IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
To study the behavior of nanofluids in heat transfer applications a revieweSAT Journals
Abstract Using nanofluids as an innovative kind of liquid blend including trivial volume fraction (in percent) of millimeter or nanometer size powdered particles with base fluids is fairly a novel arena or idea. The objective of this presented review paper is to inspect the performance of the nanofluid-based solar collector (NBSC). In past few years for a number of experimental and industrial thermal engineering systems solar energy has proven to be the best input energy source. Nanofluids are the fluid that has shown various developments in the thermal properties over the past decade. In the field of nanotechnology, nano fluids have a great potential to enhance the rheological properties like thermal conductivity of base fluid like water, ethanol etc. Nanofluids are the suspension of mainly the base fluid like water in nanoparticles such as alumina (Al2O3) of size micro or milimetre and shows distinctive features than that of conservative fluids used. Because of better rheological properties nanofluids are utilized to build up the performance of conventional solar thermal engineering systems. The presented literature review presents a detailed discussion about the solar collectors, applications of nanofluids in solar collector and their augmentation in thermo physical properties. Keywords: Nano fluids, Nanoparticles, Solar collector, Thermal conductivity
Critical heat flux enhancement in pool boiling with al2 o3 water nanofluideSAT Journals
Abstract Boiling is an important phase change phenomena as it plays a crucial role in the design of high heat flux system like boilers, heat exchangers, microscopic heat transfer devices. However boiling phenomenon is limited by critical heat flux. At critical heat flux material of heated surface suffers physical damage due to lower heat transfer resulting from thin film formed over the surface. Now a days Nanofluid which is colloidal suspension of nanoparticle in base fluid is highlighted as innovative techniques to enhance critical heat flux. In the present study Al2O3 nanoparticles were characterized by using SEM and XRD analysis. From SEM images it was seen that nanoparticle has spherical morphology, and from XRD analysis average nanoparticle size determined was 29.48 nm. Five different nanofluids of concentration range from 3 gram/liter to 15 gram/liter were prepared. Critical heat flux (CHF) of each Al2O3-water nanofluid in pool boiling is determined on NiCr wire of SWG 28. The minimum critical heat flux enhancement is 30.53% at 3 gram/liter nanofluid compared to critical heat flux of distilled water. The highest critical heat flux enhancement is 72.70 % at 12 gram/liter nanofluid. Critical heat flux of nanofluid increases with increase in concentration of Al2O3 nanoparticle in distilled water up to 12 gram/liter nanofluid. Surface roughness of bare wire was 0.126 μm. Surface roughness of wire sample used in pool boiling of 3 gram/liter nanofluid is 0.299μm and highest surface roughness was 0.715 μm of heater used in pool boiling of 12 gram/liter nanofluid. The Surface roughness measurement results show the evidence of nanoparticle deposition on wire surface and its effect on Critical Heat Flux enhancement. Keywords: Critical heat flux, Nanoparticle, Nanofluid, Concentration, Surface roughness.
IRJET- Selection of Phase Change Material using Shenon Entropy and Vikor ...IRJET Journal
This document discusses the selection of phase change materials (PCMs) for latent heat thermal energy storage using multi-criteria decision making methods. It presents the properties of several potential PCM candidates and evaluates them using the Vikor and entropy methods. First, the normalized decision matrix of PCM properties is calculated. Then, Shannon's entropy is used to determine the weights of each property criterion. Finally, the Vikor method is applied to rank the PCM alternatives based on their closeness to the ideal solution. The top performing PCM identified is a combination of PEG6000, polyurethlene and graphene.
Effect of nanofluid on heat transfer characteristics of double pipe heat exch...eSAT Journals
Abstract A nanofluid is a suspension of nano sized particles made up of metal, oxides or carbides of size up to 100 nm in a base fluid of water, ethylene glycol or oil. Recently large numbers of experiments have been are carried out to evaluate the effect of nanofluid in enhancement of the heat transfer rate in various heat exchangers. The heat transfer enhancement using nanofluid mainly depends on type of nanoparticles, size of nanoparticles, shape of nanoparticles, type of base fluid and concentration of nanoparticles in the base fluid. In the present paper, an experimental evaluation has been carried out to determine the effect of various concentration of CuO nanoparticles mixed in water on heat transfer characteristics of double pipe heat exchanger for parallel flow and counter flow arrangement. The volume concentrations of CuO nanofluid prepared by two step method are 0.002 %, 0.003% and 0.004 %. The conclusion derived for the study is that overall heat transfer coefficient increases with increase in volume concentration of CuO nanoparticle compared to water which have been validated by theoretical prediction also. Keywords: Nanofluid, Heat Transfer Characteristics, Double Pipe Heat Exchanger, CuO Nanoparticles
The document discusses nanofluids, which are engineered colloidal suspensions of nanoparticles in a base fluid. It provides an introduction to nanofluids and their properties. The document then covers preparation methods for nanofluids, factors that influence the thermal conductivity of nanofluids like Brownian motion and interfacial layers, common materials used for nanoparticles and base fluids, advantages and limitations of nanofluids, and applications. The overall document serves as a review of nanofluids that discusses their composition, properties, production methods, performance factors, and considerations for use.
Heat transfer enhancement by nanofluid Suhail Patel
The purpose of this paper is to look into the present aspects of “Nanotechnology”. This gives a brief description of how heat transfer enhances using Nanofluid And its application in various fields viz. heat transportation, military applications, medical, etc. This paper focuses one explaining the basic mechanisms of improvement in heat transfer by addition nanoparticles.
Cryogenic Treatment and Cryogenic Cooling in Die Sink Electric Discharge Mach...IJERA Editor
Integration of Cryogenic Treatment and Cryogenic Cooling with EDM process results in a newer process called as the Cryogenically Assisted Electric Discharge Machining (CEDM) process. It is one of very recent developments for the enhancement of process capabilities of EDM. In this technique, either the tool or the workpiece, or tool and workpiece both, may be, cryogenically treated down to sub zero temperatures or the EDM tool is cryogenically cooled with an objective to modify their properties. The modifications in properties result in the reduction of tool wear rate (TWR) and surface roughness (SR) and to increase material removal rate (MRR). An experimental set up for both the variants of CEDM has been discussed in the presented paper
IRJET- Effect of Nano Fluid in Multi-Cylinder Four Stroke Petrol Engine: ...IRJET Journal
This document reviews research on using nanofluids in automotive cooling systems. Nanofluids are fluids containing nanometer-sized particles that can enhance heat transfer properties compared to conventional fluids like water. The review finds that nanofluids made of particles like aluminum oxide, copper oxide, and titanium dioxide suspended in water can increase the thermal conductivity and cooling efficiency of engine radiators. Experimental studies show heat transfer improvement of up to 39% and negligible pressure drop increase when using nanofluids in radiators and heat exchangers. Overall, the literature indicates nanofluids have potential to improve cooling system performance and engine efficiency.
To study the behavior of nanofluids in heat transfer applications a revieweSAT Journals
Abstract Using nanofluids as an innovative kind of liquid blend including trivial volume fraction (in percent) of millimeter or nanometer size powdered particles with base fluids is fairly a novel arena or idea. The objective of this presented review paper is to inspect the performance of the nanofluid-based solar collector (NBSC). In past few years for a number of experimental and industrial thermal engineering systems solar energy has proven to be the best input energy source. Nanofluids are the fluid that has shown various developments in the thermal properties over the past decade. In the field of nanotechnology, nano fluids have a great potential to enhance the rheological properties like thermal conductivity of base fluid like water, ethanol etc. Nanofluids are the suspension of mainly the base fluid like water in nanoparticles such as alumina (Al2O3) of size micro or milimetre and shows distinctive features than that of conservative fluids used. Because of better rheological properties nanofluids are utilized to build up the performance of conventional solar thermal engineering systems. The presented literature review presents a detailed discussion about the solar collectors, applications of nanofluids in solar collector and their augmentation in thermo physical properties. Keywords: Nano fluids, Nanoparticles, Solar collector, Thermal conductivity
Critical heat flux enhancement in pool boiling with al2 o3 water nanofluideSAT Journals
Abstract Boiling is an important phase change phenomena as it plays a crucial role in the design of high heat flux system like boilers, heat exchangers, microscopic heat transfer devices. However boiling phenomenon is limited by critical heat flux. At critical heat flux material of heated surface suffers physical damage due to lower heat transfer resulting from thin film formed over the surface. Now a days Nanofluid which is colloidal suspension of nanoparticle in base fluid is highlighted as innovative techniques to enhance critical heat flux. In the present study Al2O3 nanoparticles were characterized by using SEM and XRD analysis. From SEM images it was seen that nanoparticle has spherical morphology, and from XRD analysis average nanoparticle size determined was 29.48 nm. Five different nanofluids of concentration range from 3 gram/liter to 15 gram/liter were prepared. Critical heat flux (CHF) of each Al2O3-water nanofluid in pool boiling is determined on NiCr wire of SWG 28. The minimum critical heat flux enhancement is 30.53% at 3 gram/liter nanofluid compared to critical heat flux of distilled water. The highest critical heat flux enhancement is 72.70 % at 12 gram/liter nanofluid. Critical heat flux of nanofluid increases with increase in concentration of Al2O3 nanoparticle in distilled water up to 12 gram/liter nanofluid. Surface roughness of bare wire was 0.126 μm. Surface roughness of wire sample used in pool boiling of 3 gram/liter nanofluid is 0.299μm and highest surface roughness was 0.715 μm of heater used in pool boiling of 12 gram/liter nanofluid. The Surface roughness measurement results show the evidence of nanoparticle deposition on wire surface and its effect on Critical Heat Flux enhancement. Keywords: Critical heat flux, Nanoparticle, Nanofluid, Concentration, Surface roughness.
IRJET- Selection of Phase Change Material using Shenon Entropy and Vikor ...IRJET Journal
This document discusses the selection of phase change materials (PCMs) for latent heat thermal energy storage using multi-criteria decision making methods. It presents the properties of several potential PCM candidates and evaluates them using the Vikor and entropy methods. First, the normalized decision matrix of PCM properties is calculated. Then, Shannon's entropy is used to determine the weights of each property criterion. Finally, the Vikor method is applied to rank the PCM alternatives based on their closeness to the ideal solution. The top performing PCM identified is a combination of PEG6000, polyurethlene and graphene.
Effect of nanofluid on heat transfer characteristics of double pipe heat exch...eSAT Journals
Abstract A nanofluid is a suspension of nano sized particles made up of metal, oxides or carbides of size up to 100 nm in a base fluid of water, ethylene glycol or oil. Recently large numbers of experiments have been are carried out to evaluate the effect of nanofluid in enhancement of the heat transfer rate in various heat exchangers. The heat transfer enhancement using nanofluid mainly depends on type of nanoparticles, size of nanoparticles, shape of nanoparticles, type of base fluid and concentration of nanoparticles in the base fluid. In the present paper, an experimental evaluation has been carried out to determine the effect of various concentration of CuO nanoparticles mixed in water on heat transfer characteristics of double pipe heat exchanger for parallel flow and counter flow arrangement. The volume concentrations of CuO nanofluid prepared by two step method are 0.002 %, 0.003% and 0.004 %. The conclusion derived for the study is that overall heat transfer coefficient increases with increase in volume concentration of CuO nanoparticle compared to water which have been validated by theoretical prediction also. Keywords: Nanofluid, Heat Transfer Characteristics, Double Pipe Heat Exchanger, CuO Nanoparticles
The document discusses nanofluids, which are engineered colloidal suspensions of nanoparticles in a base fluid. It provides an introduction to nanofluids and their properties. The document then covers preparation methods for nanofluids, factors that influence the thermal conductivity of nanofluids like Brownian motion and interfacial layers, common materials used for nanoparticles and base fluids, advantages and limitations of nanofluids, and applications. The overall document serves as a review of nanofluids that discusses their composition, properties, production methods, performance factors, and considerations for use.
Heat transfer enhancement by nanofluid Suhail Patel
The purpose of this paper is to look into the present aspects of “Nanotechnology”. This gives a brief description of how heat transfer enhances using Nanofluid And its application in various fields viz. heat transportation, military applications, medical, etc. This paper focuses one explaining the basic mechanisms of improvement in heat transfer by addition nanoparticles.
Cryogenic Treatment and Cryogenic Cooling in Die Sink Electric Discharge Mach...IJERA Editor
Integration of Cryogenic Treatment and Cryogenic Cooling with EDM process results in a newer process called as the Cryogenically Assisted Electric Discharge Machining (CEDM) process. It is one of very recent developments for the enhancement of process capabilities of EDM. In this technique, either the tool or the workpiece, or tool and workpiece both, may be, cryogenically treated down to sub zero temperatures or the EDM tool is cryogenically cooled with an objective to modify their properties. The modifications in properties result in the reduction of tool wear rate (TWR) and surface roughness (SR) and to increase material removal rate (MRR). An experimental set up for both the variants of CEDM has been discussed in the presented paper
IRJET- Effect of Nano Fluid in Multi-Cylinder Four Stroke Petrol Engine: ...IRJET Journal
This document reviews research on using nanofluids in automotive cooling systems. Nanofluids are fluids containing nanometer-sized particles that can enhance heat transfer properties compared to conventional fluids like water. The review finds that nanofluids made of particles like aluminum oxide, copper oxide, and titanium dioxide suspended in water can increase the thermal conductivity and cooling efficiency of engine radiators. Experimental studies show heat transfer improvement of up to 39% and negligible pressure drop increase when using nanofluids in radiators and heat exchangers. Overall, the literature indicates nanofluids have potential to improve cooling system performance and engine efficiency.
DESIGN AND TESTING OF PROTOTYPE MAGNETIC REFRIGERATION Muhammad Usman
Magnetic refrigeration is considered as a more reliable and sustainable source to generate cooling and effect in the working fluid using a hysteresis effect. Magnetically soft material with less hysteresis loop area has been recommended for this project.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IRJET- Performance Analysis of Vcr’s using NanorefrigerantsIRJET Journal
This document analyzes the performance of vapor compression refrigerators (VCRs) using nanorefrigerants. An experiment was conducted using a 7-liter domestic refrigerator that operated with refrigerants blended with zinc oxide (ZnO) nanoparticles and a blend of ZnO and silicon dioxide (SiO2) nanoparticles. The coefficient of performance was found to be higher compared to using the bare R134a refrigerant alone, and total energy consumption was significantly reduced. Thus, blending refrigerants with nanoparticles improves heat transfer and increases the coefficient of performance in refrigerators.
This document describes the simulation of a sand bath heater using MATLAB. It discusses:
1) The experimental setup, which includes three sand baths - two at room temperature for studying hydrodynamics and one stainless steel bath for high temperatures up to 200C with two heaters and temperature sensors.
2) The mathematical model developed to simulate fluidization and heat transfer in the bath, which is a set of ordinary differential equations describing the heat balance and air/sand temperature relationship.
3) How Simulink was used to numerically solve the model equations since they have no analytical solution, allowing experimental results to be compared to theory.
Numerical simulation and enhancement of heat transfer using cuo water nano fl...IAEME Publication
This document summarizes a study on enhancing heat transfer using CuO/water nanofluid and a twisted tape insert with alternate axis in a circular tube. Numerical simulations were performed using ANSYS FLUENT to analyze heat transfer, friction, and thermal performance of the nanofluid at various concentrations from 0.3-0.7% by volume. The simulations also examined using nanofluid with a typical twisted tape, the twisted tape alone, and nanofluid alone. Results showed that using nanofluid together with the twisted tape with alternate axis can further improve heat transfer compared to using them individually.
Study of Heat Transfer Characteristics of Nanofluid as Coolant on a Single Cylinder Diesel Engine with Spiral Radiator.
Team Members: Sandeep Raj Kanth, Viral Hitenkumar Naik, Rudra Ranjan Swain
Guide: Dr. G. Naga Srinivasulu, Assistant Professor, Mechanical Engineering Department, NIT Warangal
IRJET- Design and Fabrication of “Cavitation Water Heater”IRJET Journal
This document describes the design and fabrication of a cavitation water heater. It uses the principle of cavitation to heat water in a more efficient manner than conventional heaters. Cavitation is induced by rotating a rotor with holes inside a casing containing water. This causes bubbles to form and collapse, releasing heat. The system was tested and found to heat water using less electricity than conventional heaters. It provides direct, homogeneous heating of water without a heat transfer medium. This cavitation water heater design could provide an efficient and lower cost alternative for heating water.
Ridding of Pollution From Plastic by Turning it into Valuable Fuel using Wire...IRJET Journal
This document discusses a process for converting waste plastics into liquid fuel using pyrolysis and sensor technology. Temperature and pressure sensors monitor the pyrolysis process, which involves heating plastics in the absence of oxygen to produce combustible gases and liquid fuel. Plastics are first separated by resin type using various sorting methods. The pyrolysis reactor is heated to 310-540 degrees Celsius using electrical coils while sensors ensure accurate temperature and pressure control. This process provides a way to reduce plastic pollution while producing a valuable fuel and addressing India's need to import less petroleum.
This document summarizes a computational study on using finned heat pipes to cool photovoltaic (PV) solar panels. The study uses computational fluid dynamics (CFD) to model heat transfer from a solar panel through a heat pipe with attached fins. The CFD analysis shows that attaching fins to a heat pipe can reduce the temperature of a solar panel by up to 20°C compared to no cooling. This temperature reduction can increase the panel's efficiency and power output. The study aims to develop a passive cooling system for PV panels using a low-cost finned heat pipe design.
Investigation on effective thermal conductivity of foams using transient plan...eSAT Publishing House
The document describes an experimental setup used to determine the effective thermal conductivity of various foam materials (polyurethane foam, latex rubber foam, synthetic foam) using the transient plane heat source method. Thermal conductivity measurements were taken for each foam material at different concentrations (obtained by compressing the foam to different thicknesses). The results showed that increasing the concentration of the material (decreasing porosity) led to an increase in the effective thermal conductivity, as compressing the foam evacuated more of the low conductivity air pockets within the material.
Review Paper on Enhancement of Heat Transfer by Using Binary NanofluidsIRJET Journal
This document provides a literature review on enhancing heat transfer using binary nanofluids. It discusses research that has been conducted on improving critical heat flux and boiling heat transfer by using nanofluids made of nanoparticles suspended in a base fluid. The key findings are:
1) Experiments show that nanofluids can increase critical heat flux by 20-300% compared to water alone, with the level of enhancement depending on nanoparticle material, size, concentration, and other factors.
2) Nanoparticle deposition on heater surfaces during boiling is observed to increase surface roughness and wettability, enhancing critical heat flux.
3) Both pool boiling and convective flow boiling experiments demonstrate heat transfer coefficient and critical heat
IRJET- Experimental Analysis on Power Generation Unit using R134a Powered...IRJET Journal
This document describes an experimental analysis of a power generation unit that uses solar energy concentrated by a Fresnel lens to power an Organic Rankine Cycle (ORC) and generate electricity. R134a refrigerant is used as the working fluid. Key points:
- A Fresnel lens concentrates solar energy to heat a copper tube, vaporizing the R134a working fluid.
- The vapor drives a turbine that powers a generator. Lower boiling point fluids like R134a allow utilization of lower solar temperatures compared to water.
- Calculations are shown for system parameters like heat transfer rate, pressure drop, turbine power output, and thermal efficiency based on the ORC using R134a.
The document provides a literature review on the effects of nanofluids in enhancing thermophysical properties. It discusses how adding nanoparticles to base fluids can increase thermal conductivity. The summary discusses how decreasing nanoparticle size and increasing temperature and volume fraction can further increase thermal conductivity. Prior studies found thermal conductivity enhancement was highest for nanofluids with smaller nanoparticle sizes (<50nm) and at higher temperatures. The literature review examines several past studies that investigated these effects and relationships between properties.
IRJET- Heat Exchanger based on Nano FluidIRJET Journal
The document discusses using nanofluids to improve heat transfer in a heat exchanger. It begins by introducing nanofluids and their potential to increase heat transfer rates compared to conventional fluids. It then describes the experimental setup to test a heat exchanger using water and metal-based nanofluids. Temperature sensors will measure the inlet and outlet temperatures of the two fluids while flow control valves regulate flow rates. The goal is to study the effect of mass flow rates on heat exchanger efficiency. CAD software was used to model the design. Experimental testing will obtain results and conclusions on the heat exchanger's performance using nanofluids versus just water.
IRJET- Flow and Heat Transfer Charecterstics of Multiple Jet CoolingIRJET Journal
The document summarizes research on heat transfer characteristics of multiple jet cooling for electronic components. Experiments were conducted using an array of 49 water jets impinging on an electrically heated copper plate. The jet diameter was 0.5mm, arranged in a 7x7 square array with 3mm pitch. Tests were run at flow rates of 22-40 ml/min and heat fluxes of 25-200W/cm2. Results showed that heat transfer coefficient, or Nusselt number, increased with increasing heat flux and Reynolds number. Prior studies on jet impingement cooling are also summarized.
Preparation And comaparision of alluminium nanofluid with bsae fluidMrutyunjaya Swain
This project report summarizes research on the preparation and comparison of Al2O3-water nanofluid with a base fluid. Nanofluids are suspensions of nanoparticles in a base fluid that can improve heat transfer properties. The report describes how nanofluids were prepared using single-step and two-step methods and their thermal conductivity was measured and found to be higher than the base fluids alone. Potential applications of nanofluids include industrial cooling, automotive cooling, electronic cooling, and biomedical uses. However, nanofluids also have limitations such as potentially lower specific heat and higher costs.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Case study on slender multi storey rc building with brick infilleSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
This document presents a methodology for real-time object tracking using a webcam. It combines Prewitt edge detection for object detection and Kalman filtering for tracking. Prewitt edge detection is used to detect the edges of the moving object in each video frame. Then, Kalman filtering is used to track the detected object across subsequent frames by predicting its location. Experiments show the approach can efficiently track objects under deformation, occlusion, and can track multiple objects simultaneously. The combination of Prewitt edge detection and Kalman filtering provides an effective method for real-time object tracking.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
DESIGN AND TESTING OF PROTOTYPE MAGNETIC REFRIGERATION Muhammad Usman
Magnetic refrigeration is considered as a more reliable and sustainable source to generate cooling and effect in the working fluid using a hysteresis effect. Magnetically soft material with less hysteresis loop area has been recommended for this project.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IRJET- Performance Analysis of Vcr’s using NanorefrigerantsIRJET Journal
This document analyzes the performance of vapor compression refrigerators (VCRs) using nanorefrigerants. An experiment was conducted using a 7-liter domestic refrigerator that operated with refrigerants blended with zinc oxide (ZnO) nanoparticles and a blend of ZnO and silicon dioxide (SiO2) nanoparticles. The coefficient of performance was found to be higher compared to using the bare R134a refrigerant alone, and total energy consumption was significantly reduced. Thus, blending refrigerants with nanoparticles improves heat transfer and increases the coefficient of performance in refrigerators.
This document describes the simulation of a sand bath heater using MATLAB. It discusses:
1) The experimental setup, which includes three sand baths - two at room temperature for studying hydrodynamics and one stainless steel bath for high temperatures up to 200C with two heaters and temperature sensors.
2) The mathematical model developed to simulate fluidization and heat transfer in the bath, which is a set of ordinary differential equations describing the heat balance and air/sand temperature relationship.
3) How Simulink was used to numerically solve the model equations since they have no analytical solution, allowing experimental results to be compared to theory.
Numerical simulation and enhancement of heat transfer using cuo water nano fl...IAEME Publication
This document summarizes a study on enhancing heat transfer using CuO/water nanofluid and a twisted tape insert with alternate axis in a circular tube. Numerical simulations were performed using ANSYS FLUENT to analyze heat transfer, friction, and thermal performance of the nanofluid at various concentrations from 0.3-0.7% by volume. The simulations also examined using nanofluid with a typical twisted tape, the twisted tape alone, and nanofluid alone. Results showed that using nanofluid together with the twisted tape with alternate axis can further improve heat transfer compared to using them individually.
Study of Heat Transfer Characteristics of Nanofluid as Coolant on a Single Cylinder Diesel Engine with Spiral Radiator.
Team Members: Sandeep Raj Kanth, Viral Hitenkumar Naik, Rudra Ranjan Swain
Guide: Dr. G. Naga Srinivasulu, Assistant Professor, Mechanical Engineering Department, NIT Warangal
IRJET- Design and Fabrication of “Cavitation Water Heater”IRJET Journal
This document describes the design and fabrication of a cavitation water heater. It uses the principle of cavitation to heat water in a more efficient manner than conventional heaters. Cavitation is induced by rotating a rotor with holes inside a casing containing water. This causes bubbles to form and collapse, releasing heat. The system was tested and found to heat water using less electricity than conventional heaters. It provides direct, homogeneous heating of water without a heat transfer medium. This cavitation water heater design could provide an efficient and lower cost alternative for heating water.
Ridding of Pollution From Plastic by Turning it into Valuable Fuel using Wire...IRJET Journal
This document discusses a process for converting waste plastics into liquid fuel using pyrolysis and sensor technology. Temperature and pressure sensors monitor the pyrolysis process, which involves heating plastics in the absence of oxygen to produce combustible gases and liquid fuel. Plastics are first separated by resin type using various sorting methods. The pyrolysis reactor is heated to 310-540 degrees Celsius using electrical coils while sensors ensure accurate temperature and pressure control. This process provides a way to reduce plastic pollution while producing a valuable fuel and addressing India's need to import less petroleum.
This document summarizes a computational study on using finned heat pipes to cool photovoltaic (PV) solar panels. The study uses computational fluid dynamics (CFD) to model heat transfer from a solar panel through a heat pipe with attached fins. The CFD analysis shows that attaching fins to a heat pipe can reduce the temperature of a solar panel by up to 20°C compared to no cooling. This temperature reduction can increase the panel's efficiency and power output. The study aims to develop a passive cooling system for PV panels using a low-cost finned heat pipe design.
Investigation on effective thermal conductivity of foams using transient plan...eSAT Publishing House
The document describes an experimental setup used to determine the effective thermal conductivity of various foam materials (polyurethane foam, latex rubber foam, synthetic foam) using the transient plane heat source method. Thermal conductivity measurements were taken for each foam material at different concentrations (obtained by compressing the foam to different thicknesses). The results showed that increasing the concentration of the material (decreasing porosity) led to an increase in the effective thermal conductivity, as compressing the foam evacuated more of the low conductivity air pockets within the material.
Review Paper on Enhancement of Heat Transfer by Using Binary NanofluidsIRJET Journal
This document provides a literature review on enhancing heat transfer using binary nanofluids. It discusses research that has been conducted on improving critical heat flux and boiling heat transfer by using nanofluids made of nanoparticles suspended in a base fluid. The key findings are:
1) Experiments show that nanofluids can increase critical heat flux by 20-300% compared to water alone, with the level of enhancement depending on nanoparticle material, size, concentration, and other factors.
2) Nanoparticle deposition on heater surfaces during boiling is observed to increase surface roughness and wettability, enhancing critical heat flux.
3) Both pool boiling and convective flow boiling experiments demonstrate heat transfer coefficient and critical heat
IRJET- Experimental Analysis on Power Generation Unit using R134a Powered...IRJET Journal
This document describes an experimental analysis of a power generation unit that uses solar energy concentrated by a Fresnel lens to power an Organic Rankine Cycle (ORC) and generate electricity. R134a refrigerant is used as the working fluid. Key points:
- A Fresnel lens concentrates solar energy to heat a copper tube, vaporizing the R134a working fluid.
- The vapor drives a turbine that powers a generator. Lower boiling point fluids like R134a allow utilization of lower solar temperatures compared to water.
- Calculations are shown for system parameters like heat transfer rate, pressure drop, turbine power output, and thermal efficiency based on the ORC using R134a.
The document provides a literature review on the effects of nanofluids in enhancing thermophysical properties. It discusses how adding nanoparticles to base fluids can increase thermal conductivity. The summary discusses how decreasing nanoparticle size and increasing temperature and volume fraction can further increase thermal conductivity. Prior studies found thermal conductivity enhancement was highest for nanofluids with smaller nanoparticle sizes (<50nm) and at higher temperatures. The literature review examines several past studies that investigated these effects and relationships between properties.
IRJET- Heat Exchanger based on Nano FluidIRJET Journal
The document discusses using nanofluids to improve heat transfer in a heat exchanger. It begins by introducing nanofluids and their potential to increase heat transfer rates compared to conventional fluids. It then describes the experimental setup to test a heat exchanger using water and metal-based nanofluids. Temperature sensors will measure the inlet and outlet temperatures of the two fluids while flow control valves regulate flow rates. The goal is to study the effect of mass flow rates on heat exchanger efficiency. CAD software was used to model the design. Experimental testing will obtain results and conclusions on the heat exchanger's performance using nanofluids versus just water.
IRJET- Flow and Heat Transfer Charecterstics of Multiple Jet CoolingIRJET Journal
The document summarizes research on heat transfer characteristics of multiple jet cooling for electronic components. Experiments were conducted using an array of 49 water jets impinging on an electrically heated copper plate. The jet diameter was 0.5mm, arranged in a 7x7 square array with 3mm pitch. Tests were run at flow rates of 22-40 ml/min and heat fluxes of 25-200W/cm2. Results showed that heat transfer coefficient, or Nusselt number, increased with increasing heat flux and Reynolds number. Prior studies on jet impingement cooling are also summarized.
Preparation And comaparision of alluminium nanofluid with bsae fluidMrutyunjaya Swain
This project report summarizes research on the preparation and comparison of Al2O3-water nanofluid with a base fluid. Nanofluids are suspensions of nanoparticles in a base fluid that can improve heat transfer properties. The report describes how nanofluids were prepared using single-step and two-step methods and their thermal conductivity was measured and found to be higher than the base fluids alone. Potential applications of nanofluids include industrial cooling, automotive cooling, electronic cooling, and biomedical uses. However, nanofluids also have limitations such as potentially lower specific heat and higher costs.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Case study on slender multi storey rc building with brick infilleSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
This document presents a methodology for real-time object tracking using a webcam. It combines Prewitt edge detection for object detection and Kalman filtering for tracking. Prewitt edge detection is used to detect the edges of the moving object in each video frame. Then, Kalman filtering is used to track the detected object across subsequent frames by predicting its location. Experiments show the approach can efficiently track objects under deformation, occlusion, and can track multiple objects simultaneously. The combination of Prewitt edge detection and Kalman filtering provides an effective method for real-time object tracking.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
A hydration study by xrdrietveld analysis of cement regenerated from complete...eSAT Publishing House
This document summarizes a study that used X-ray diffraction and Rietveld analysis to examine the hydration of cement regenerated from concrete designed to be completely recyclable. Specifically, it analyzed samples of cement paste in which hydration was arrested at various time points up to 28 days. The results showed that the alite and belite phases decreased over time as portlandite and amorphous calcium silicate hydrate (C-S-H) increased. Aluminate phases dissolved completely while ferrite decreased. Some differences were seen in the mineralogy of cement produced from recycled concrete versus ordinary portland cement, but the hydration processes were similar. The study highlighted the importance of sample preparation methods on the
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
A short review on microemulsion and its application in extraction of vegetabl...eSAT Publishing House
This document summarizes microemulsion technology and its application in oil extraction. Microemulsions are thermodynamically stable, transparent systems containing oil, water, surfactant and co-surfactant that form spontaneously. They have droplet sizes below 100nm. Microemulsions can extract oils using less hazardous solvents than conventional methods. Winsor classified microemulsions into four types based on phase behavior. Microemulsions can be prepared by phase inversion, where the emulsion type changes with temperature or composition changes. Microemulsions provide an efficient approach for oil extraction from oilseeds with benefits over conventional extraction techniques.
Flip invariant video copy detection using sparse-coded featureseSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Availability analysis of parallel transit fuel system in petrol engine under ...eSAT Publishing House
This document summarizes a research paper that analyzes the availability of a parallel transit fuel system in a petrol engine. The fuel system has two subsystems (A and B) in series, with subsystem A having two fuel sources as a backup. Subsystem failures follow an exponential distribution and repairs follow a general distribution. The author uses Laplace transforms to obtain equations governing the behavior of the system and its state probabilities. Key results include expressions for the steady-state probabilities of different system states and the long-term availability of the overall fuel system.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Human action recognition using local space time features and adaboost svmeSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Status of noise in yeshwanthpur circle (bangalore north) based on on site dat...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Analysis of wireless sensor networks security, attacks and challengeseSAT Publishing House
This document summarizes the analysis of wireless sensor networks, including security issues, attacks, and challenges. It discusses the characteristics of wireless sensor networks and their architecture. It outlines various security goals for wireless sensor networks, including confidentiality, integrity, authentication, and availability. It then describes different types of attacks against wireless sensor networks at the physical, link, network, and transport layers. These include jamming, tampering, exhaustion, collision, and flooding attacks. Finally, it discusses key challenges for wireless sensor networks, such as limited resources, heterogeneous platforms, dynamic network topologies, and handling mixed traffic from different applications.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Comparative study of tribological characteristics of aa2024+10% fly ash compo...eSAT Journals
Abstract There has been search for the low cost and low density reinforcements for reducing the cost of composites. One prospective reinforcement in this regard is the fly ash, which is abundantly available as a waste product from thermal power plants. Because of unique nature of physical and chemical properties of the fly ash it is tried as reinforcement by many researchers in the recent past. In the present investigation composite used contains fly ash particles [10% by wt] reinforced with wrought aluminium alloy AA2024. The composite is tested for tribological behaviour in the Non-Heat Treated [NHT] and Heat-Treated [HT] conditions under different working parameters in a pin-on-disc tribometer. The results of the experiment indicate that the dispersion of fly ash particles in the AA2024 alloy matrix would increase the wear resistance of matrix alloy. It’s observed that a significant improvement in wear performance is achieved by heat treating the composite. The water quenched specimen showed a better properties as compared to air cooled and NHT counterparts. Keywords: fly ash, composite, heat-treatment, wear and microstructure
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Investigation on the activating effect of na2 co3 and naoh on slageSAT Publishing House
This document investigates the activating effect of sodium carbonate (Na2CO3) and sodium hydroxide (NaOH) on the workability and compressive strength of alkali-activated slag materials. Heat release experiments show that slag activated with Na2CO3 reacts much slower than slag activated with NaOH, with the main reaction occurring around 40 hours after mixing compared to 30 minutes for NaOH. Testing of workability and 7-day compressive strength was done with different alkali dosages and water-to-binder ratios. In general, Na2CO3 provided higher fluidity and strength compared to NaOH under the same conditions.
Abstract
The present day scenario of the modern world is impossible to imagine without automobile. Thus it a primary challenge for automobile industries to design efficient and cost effective engine. The performance of the engine again depends on the type of fuel used, the cooling system, the lubrication system, the range of temperature in which the engine works etc. If the factors are taken care of then the performance of the engine can be improved. In this paper the effect of the fuel assimilating metallic nano-particles is studied. After the combustion of fuel in the combustion chamber the byproducts of combustion (water vapor and carbon dioxide) are further disintegrated, the dissociation of water being an exothermal process adds up to the heat intake of the engine. The food for the engine being heat and not the fuel, it is beneficial in every sense to extract maximum possible amount of heat from the given mass of fuel. This process has both merits and demerits which are shown by the comprehensive study of the fuel used in an internal combustion engine, the chemical process involved in the combustion and the process of exhaust.
Keywords: Nanofluids, Heat Transfer, Conductivity, Knocking and Detonation, Thermal Diffusibility.
The Effect of Milling Times and Annealing on Synthesis of Strontium Titanate ...AM Publications
Analysis of microstructure of Strontium titanate (SrTiO3) phase obtained by milling and annealing of
SrCO3 and TiO2 precursors. However, the material properties for strontium titanate require a careful control of
crystallite structure as well as microstructure design to meet a specific application. The mixture of strontium
carbonate (SrCO3) and tintanium oxide (TiO2) powders was used to obtain SrTiO3 phase by using vibrator ball mill
with ball to powder ratio 10:1 and heat treatment processes. The size of powder particles was determined by a laser
particle analyzer (PSA). The X-ray diffraction methods were used for qualitative, quantitative phase analyses and for
crystallite size and lattice distortion determination. The milling process of strontium carbonate and tintanium oxide
mixture causes decrease of the mean particle size and crystallite size of involved phases. The X-ray diffraction
investigations of SrCO3 and TiO2 mixture milled for 60 hours and annealed at 900°C with 24 h of holding time
enabled the identification of SrTiO3 phase. Annealing the sample of the particles at 900 0C has resulted in a dense
compact and promoted the formation of particles containing nanocrystallites. The crystallite-growth samples of
SrTiO3 phase were dependent on temperature and time of their annealing
IRJET- Design and Analysis of Absorber Tube of Solar Parabolic trough CollectorIRJET Journal
This document discusses a computational fluid dynamics (CFD) analysis of the fluid flow and heat transfer in the absorber tube of a parabolic trough solar collector with and without internal inserts. The CFD analysis is conducted to study the effect of different insert profiles on heat transfer and compare results to an absorber tube without inserts. The goal is to improve the efficiency of heat transfer from the absorber tube wall to the working fluid by increasing contact area between the fluid and tube, increasing residual time of the fluid, and decreasing fluid velocity using inserts or internal fins.
Preparation and characterization of microfiltration ceramic membrane for oily...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Time dependent behaviour of a class f fly ash-based geopolymer concreteeSAT Publishing House
This document summarizes a study on the time-dependent behavior of a class F fly ash-based geopolymer concrete. The concrete was composed of 85.2% low-calcium fly ash and 14.8% GGBFS. The study examined the effects of different curing regimes (1 day at 40°C, 1 day at 80°C, 3 days at 40°C, 7 days at 80°C) on drying shrinkage and creep behavior over time. Results showed that a minimum of 3 days curing at 40°C or 1 day at 80°C was needed to reduce drying shrinkage to levels predicted for OPC concrete. Creep strains were reduced by 70% compared to OPC
IRJET- Enhancement of Thermal Properties of Dielectric by Adding NanoparticleIRJET Journal
This document discusses enhancing the thermal properties of dielectric fluids used in electric discharge machining (EDM) by adding copper nanoparticles. Experiments were conducted adding copper nanoparticles to the dielectric fluid in EDM to investigate the impact on material removal rate, surface roughness, and thermal conductivity. It was found that adding nanoparticles increased the thermal conductivity of the dielectric fluid, which led to increases in material removal rate of 18-36% compared to conventional EDM without nanoparticles. The document provides background on EDM processes, nanoparticle production methods, and thermal conductivity of dielectric fluids.
This document discusses microwave-assisted pyrolysis of plastic waste. It begins by introducing the problem of increasing plastic waste and discusses pyrolysis as a potential solution. It then describes the design of a microwave reactor for pyrolyzing plastic waste, with a quartz reactor vessel and ability to heat using microwaves. Experiments were conducted with a mixture of plastics and carbon black as the microwave absorber. Products were analyzed using various techniques and the char was characterized. The results suggest microwave pyrolysis may be an effective way to treat plastic waste.
Enhancement of the output power generated from a hybrid solar thermal systemeSAT Journals
Abstract This paper investigates the output power and increased the efficiency of a hybrid Photovoltaic/ Thermal (PV/T) modules through utilizing the heat generated from the surface of panels by one axial tracking of the hybrid PV/Tsystem by means of zenith angle and decreasing the heat generated from the PV modules by controlling the flow rate of the system. A comparison between theoretical and experimental work results for fixed and tracking PV/T hybrid system is presented. Comsol software package used to simulate the electromagnetic waves produced by the sun through solving Maxwell's equations in three dimensions and the sun irradiance is assumed to be Gaussian distribution across the twelve mourning hours. Beside that an experimental work is presented depending on the results conjured from the theoretical experience used in Comsol Multiphysics In the second part of the experimental work, one axial sun-tracking system is designed where the movement of a photo-voltaic module is controlled to follow the Sun’s radiation using a Data acquisition card (DAQ) unit. Finally an active cooling system is designed and conducted to cool the fixed and tracking modules at which an absorber system consists of copper pipe welded with aluminium plate is attached underneath the PV modules to allow water flowing below the modules. In addition to the above an electrical analysis for both systems are presented where I-V, P-V, power with 12 mourning hour’s and electrical efficiency. Beside that the thermal analysis for the fixed and tracking PV modules and the piping water are presented where the input, output temperatures, the total energy of heat losses and thermal efficiency are calculated. As a result, a significant enhancement in the total electrical efficiency is observed with acceptable increase in the output water temperature. Keywords: Cooling systems; DAQ; Hybrid; Comsol Multiphysics; Mat lab; Solid work; Lab view.…
Effect of nanofluids and mass flow rate of air on heat transfer rate in autom...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
DESIGN, SIMULATION AND ANALYSIS OF A HYBRID-TYPE (PV/T) SOLAR AIR HEATER FOR ...ijiert bestjournal
This paper deals with the numerical analysis of a H ybrid-Type (PV/T) Solar Air Heater and a study on t he effect of various design parameters that enhance th e performance of the system. The heat transfer improvement in general may be achieved by increasin g the heat transfer coefficient or by increasing th e surface area or by increasing both. The main object ive of the present work is to determine the optimum air mass flow rate at which PV/T systems are to be oper ated and to develop an optimal design of a hybrid t ype (PV/T) solar air heater that shows better performan ce at various heat fluxes due to solar radiation. T his study determines the set of design parameters which lead to the best annual yield of the system. In th is study of a hybrid type (PV/T) solar air heater ICEM CFD (ANSYS) is used to obtain the optimum results,there by increasing the efficiency of the system.
COMPUTATIONAL STUDY OF COOLING OF PV SOLAR PANEL USING FINNED HEAT PIPE TECHN...IAEME Publication
Various solar energy technologies exist and they have different application techniques in the generation of electrical power. The widespread use of photovoltaic (PV) modules in such
technologies has been relatively high costs and low efficiencies. The efficiency of PV panel decreases as the operating temperature increases. This is due to reflection from the top surface, absorption of heat by the parts other than the cell, absorption of heat from the other portion of the spectrum.
The document reviews various solar distillation technologies for desalination. It discusses different types of solar concentrators and collectors that can be used to heat saline water and produce fresh water through distillation. Several studies that have tested different solar distillation designs and configurations are summarized. These include designs using parabolic concentrators, double pass solar air heaters, humidification-dehumidification processes, and systems combining multiple technologies. The document indicates that solar distillation is a promising technology for desalination using renewable energy but further improvements are needed to increase efficiency and competitiveness compared to conventional thermal desalination methods.
IRJET- Testing and Analysis of Shell and Tube Heat Exchanger by using Nan...IRJET Journal
This document discusses testing and analysis of a shell and tube heat exchanger using an alumina-water nanofluid. Key points include:
- Nanofluids are fluids containing nanoparticles that can enhance heat transfer properties compared to base fluids like water. Alumina nanoparticles were used here.
- Experiments were conducted on a shell and tube heat exchanger to analyze the effect of nanofluid on thermal conductivity and heat transfer performance.
- Results showed the nanofluid increased thermal conductivity and heat transfer coefficient compared to water alone, with higher enhancement at a 2% nanoparticle concentration. Friction factor also increased due to higher nanofluid viscosity.
Heat transfer enhancement through different circular diametrical dimple surfa...eSAT Journals
Abstract The prime objective of present work is to study experimentally the heat transfer enhancement through different circular diametrical dimple surfaces in longitudinal and lateral directions. In this paper horizontal rectangular plates of Stainless Steel and Galvanised Iron with different circular diametrical dimples (like 11mm , 14mm ) for in-line arrangements were studied in forced convection with varying laminar external flow condition. The various parameters considered for study are Reynolds Number, Nusselt number, Prandtl Number, Co-efficient of Friction, Heat transfer coefficient and heat transfer rate for a constant Prandtl number (0.698) It has been found that the heat transfer coefficient and heat transfer rate increases for various dimple surfaces as compared to plane surface. It has been also found that the heat transfer coefficient and heat transfer rate increases along longitudinal direction as compared to lateral direction. And it is seen that heat transfer rate is maximum for larger diameter (14mm) of dimple. For circular dimples, heat transfer enhancements (relative to a flat plate) were observed for Reynolds number range from 350 to 550. Index Terms: Dimple plates, Forced Convection, Heat transfer Enhancement
Performance Analysis of Forced Convection Solar Dryer for TurmericIRJET Journal
This document describes the design, development, and performance analysis of a forced convection solar dryer for drying turmeric. Key points:
1) A forced convection solar dryer was designed and built consisting of a solar collector, blower, drying chamber, and supporting frame. Experiments were conducted drying turmeric using this solar dryer.
2) Results showed that turmeric could be dried from an initial 85.33% moisture content to a final 10.76% moisture content within 48 hours of sunshine using the solar dryer, much faster than open-air drying.
3) Drying time, solar intensity, moisture loss, and dryer efficiency were evaluated under different experimental conditions. The solar
Experimental studies on pressure drop in a sinusoidal plate heat exchanger ef...eSAT Publishing House
The document summarizes experimental studies on pressure drop in a sinusoidal plate heat exchanger with varying corrugation angles. Three plate heat exchangers were fabricated with corrugation angles of 30, 40, and 50 degrees. Experiments with water flow showed that pressure drop and friction factor are affected by the corrugation angle. Pressure drop increased linearly with Reynolds number and was highest for the 50 degree angle. Friction factor decreased linearly with Reynolds number on a logarithmic scale and was lowest for the 50 degree angle. The results indicate that higher corrugation angles induce more turbulence, increasing pressure drop but decreasing friction factor.
Similar to Design parameters to obtain al2 o3 nanofluid to enhance (20)
Hudhud cyclone caused extensive damage in Visakhapatnam, India in October 2014, especially to tree cover. This will likely impact the local environment in several ways: increased air pollution as trees absorb less; higher temperatures without tree canopy; increased erosion and landslides. It also created large amounts of waste from destroyed trees. Proper management of solid waste is needed to prevent disease spread. Suggested measures include restoring damaged plants, building fountains to reduce heat, mandating light-colored buildings, improving waste management, and educating public on health risks. Overall, changes are needed to water, land, and waste practices to rebuild the environment after the cyclone removed green cover.
Impact of flood disaster in a drought prone area – case study of alampur vill...eSAT Publishing House
1) In September-October 2009, unprecedented heavy rainfall and dam releases caused widespread flooding in Alampur village in Mahabub Nagar district, a historically drought-prone area.
2) The flood damaged or destroyed homes, buildings, infrastructure, crops, and documents. It displaced many residents and cut off the village.
3) The socioeconomic conditions and mud-based construction of homes in the village exacerbated the flood's impacts, making damage more severe and recovery more difficult.
The document summarizes the Hudhud cyclone that struck Visakhapatnam, India in October 2014. It describes the cyclone's formation, rapid intensification to winds of 175 km/h, and landfall near Visakhapatnam. The cyclone caused extensive damage estimated at over $1 billion and at least 109 deaths in India and Nepal. Infrastructure like buildings, bridges, and power lines were destroyed. Crops and fishing boats were also damaged. The document then discusses coping strategies and improvements needed to disaster management plans to better prepare for future cyclones.
Groundwater investigation using geophysical methods a case study of pydibhim...eSAT Publishing House
This document summarizes the results of a geophysical investigation using vertical electrical sounding (VES) methods at 13 locations around an industrial area in India. The VES data was interpreted to generate geo-electric sections and pseudo-sections showing subsurface resistivity variations. Three main layers were typically identified - a high resistivity topsoil, a weathered middle layer, and a basement rock. Pseudo-sections revealed relatively more weathered areas in the northwest and southwest. Resistivity sections helped identify zones of possible high groundwater potential based on low resistivity anomalies sandwiched between more resistive layers. The study concluded the electrical resistivity method was useful for understanding subsurface geology and identifying areas prospective for groundwater exploration.
Flood related disasters concerned to urban flooding in bangalore, indiaeSAT Publishing House
1. The document discusses urban flooding in Bangalore, India. It describes how factors like heavy rainfall, population growth, and improper land use have contributed to increased flooding in the city.
2. Flooding events in 2013 are analyzed in detail. A November rainfall caused runoff six times higher than the drainage capacity, inundating low-lying residential areas.
3. Impacts of urban flooding include disrupted daily life, damaged infrastructure, and decreased economic activity in affected areas. The document calls for improved flood management strategies to better mitigate urban flooding risks in Bangalore.
Enhancing post disaster recovery by optimal infrastructure capacity buildingeSAT Publishing House
This document discusses enhancing post-disaster recovery through optimal infrastructure capacity building. It presents a model to minimize the cost of meeting demand using auxiliary capacities when disaster damages infrastructure. The model uses genetic algorithms to select optimal capacity combinations. The document reviews how infrastructure provides vital services supporting recovery activities and discusses classifying infrastructure into six types. When disaster reduces infrastructure services, a gap forms between community demands and available support, hindering recovery. The proposed research aims to identify this gap and optimize capacity selection to fill it cost-effectively.
Effect of lintel and lintel band on the global performance of reinforced conc...eSAT Publishing House
This document analyzes the effect of lintels and lintel bands on the seismic performance of reinforced concrete masonry infilled frames through non-linear static pushover analysis. Four frame models are considered: a frame with a full masonry infill wall; a frame with a central opening but no lintel/band; a frame with a lintel above the opening; and a frame with a lintel band above the opening. The results show that the full infill wall model has 27% higher stiffness and 32% higher strength than the model with just an opening. Models with lintels or lintel bands have slightly higher strength and stiffness than the model with just an opening. The document concludes lintels and lintel
Wind damage to trees in the gitam university campus at visakhapatnam by cyclo...eSAT Publishing House
1) A cyclone with wind speeds of 175-200 kph caused massive damage to the green cover of Gitam University campus in Visakhapatnam, India. Thousands of trees were uprooted or damaged.
2) A study assessed different types of damage to trees from the cyclone, including defoliation, salt spray damage, damage to stems/branches, and uprooting. Certain tree species were more vulnerable than others.
3) The results of the study can help in selecting more wind-resistant tree species for future planting and reducing damage from future storms.
Wind damage to buildings, infrastrucuture and landscape elements along the be...eSAT Publishing House
1) A visual study was conducted to assess wind damage from Cyclone Hudhud along the 27km Visakha-Bheemli Beach road in Visakhapatnam, India.
2) Residential and commercial buildings suffered extensive roof damage, while glass facades on hotels and restaurants were shattered. Infrastructure like electricity poles and bus shelters were destroyed.
3) Landscape elements faced damage, including collapsed trees that damaged pavements, and debris in parks. The cyclone wiped out over half the city's green cover and caused beach erosion around protected areas.
1) The document reviews factors that influence the shear strength of reinforced concrete deep beams, including compressive strength of concrete, percentage of tension reinforcement, vertical and horizontal web reinforcement, aggregate interlock, shear span-to-depth ratio, loading distribution, side cover, and beam depth.
2) It finds that compressive strength of concrete, tension reinforcement percentage, and web reinforcement all increase shear strength, while shear strength decreases as shear span-to-depth ratio increases.
3) The distribution and amount of vertical and horizontal web reinforcement also affects shear strength, but closely spaced stirrups do not necessarily enhance capacity or performance.
Role of voluntary teams of professional engineers in dissater management – ex...eSAT Publishing House
1) A team of 17 professional engineers from various disciplines called the "Griha Seva" team volunteered after the 2001 Gujarat earthquake to provide technical assistance.
2) The team conducted site visits, assessments, testing and recommended retrofitting strategies for damaged structures in Bhuj and Ahmedabad. They were able to fully assess and retrofit 20 buildings in Ahmedabad.
3) Factors observed that exacerbated the earthquake's impacts included unplanned construction, non-engineered buildings, improper prior retrofitting, and defective materials and workmanship. The professional engineers' technical expertise was crucial for effective post-disaster management.
This document discusses risk analysis and environmental hazard management. It begins by defining risk, hazard, and toxicity. It then outlines the steps involved in hazard identification, including HAZID, HAZOP, and HAZAN. The document presents a case study of a hypothetical gas collecting station, identifying potential accidents and hazards. It discusses quantitative and qualitative approaches to risk analysis, including calculating a fire and explosion index. The document concludes by discussing hazard management strategies like preventative measures, control measures, fire protection, relief operations, and the importance of training personnel on safety.
Review study on performance of seismically tested repaired shear wallseSAT Publishing House
This document summarizes research on the performance of reinforced concrete shear walls that have been repaired after damage. It begins with an introduction to shear walls and their failure modes. The literature review then discusses the behavior of original shear walls as well as different repair techniques tested by other researchers, including conventional repair with new concrete, jacketing with steel plates or concrete, and use of fiber reinforced polymers. The document focuses on evaluating the strength retention of shear walls after being repaired with various methods.
Monitoring and assessment of air quality with reference to dust particles (pm...eSAT Publishing House
This document summarizes a study on monitoring and assessing air quality with respect to dust particles (PM10 and PM2.5) in the urban environment of Visakhapatnam, India. Sampling was conducted in residential, commercial, and industrial areas from October 2013 to August 2014. The average PM2.5 and PM10 concentrations were within limits in residential areas but moderate to high in commercial and industrial areas. Exceedance factor levels indicated moderate pollution for residential areas and moderate to high pollution for commercial and industrial areas. There is a need for management measures like improved public transport and green spaces to combat particulate air pollution in the study areas.
Low cost wireless sensor networks and smartphone applications for disaster ma...eSAT Publishing House
This document describes a low-cost wireless sensor network and smartphone application system for disaster management. The system uses an Arduino-based wireless sensor network comprising nodes with various sensors to monitor the environment. The sensor data is transmitted to a central gateway and then to the cloud for analysis. A smartphone app connected to the cloud can detect disasters from the sensor data and send real-time alerts to users to help with early evacuation. The system aims to provide low-cost localized disaster detection and warnings to improve safety.
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Time Division Multiplexing (TDM) is a method of transmitting multiple signals over a single communication channel by dividing the signal into many segments, each having a very short duration of time. These time slots are then allocated to different data streams, allowing multiple signals to share the same transmission medium efficiently. TDM is widely used in telecommunications and data communication systems.
### How TDM Works
1. **Time Slots Allocation**: The core principle of TDM is to assign distinct time slots to each signal. During each time slot, the respective signal is transmitted, and then the process repeats cyclically. For example, if there are four signals to be transmitted, the TDM cycle will divide time into four slots, each assigned to one signal.
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3. **Frame Structure**: TDM data is organized into frames, where each frame consists of a set of time slots. Each frame is repeated at regular intervals, ensuring continuous transmission of data streams. The frame structure helps in managing the data streams and maintaining the synchronization between the transmitter and receiver.
4. **Multiplexer and Demultiplexer**: At the transmitting end, a multiplexer combines multiple input signals into a single composite signal by assigning each signal to a specific time slot. At the receiving end, a demultiplexer separates the composite signal back into individual signals based on their respective time slots.
### Types of TDM
1. **Synchronous TDM**: In synchronous TDM, time slots are pre-assigned to each signal, regardless of whether the signal has data to transmit or not. This can lead to inefficiencies if some time slots remain empty due to the absence of data.
2. **Asynchronous TDM (or Statistical TDM)**: Asynchronous TDM addresses the inefficiencies of synchronous TDM by allocating time slots dynamically based on the presence of data. Time slots are assigned only when there is data to transmit, which optimizes the use of the communication channel.
### Applications of TDM
- **Telecommunications**: TDM is extensively used in telecommunication systems, such as in T1 and E1 lines, where multiple telephone calls are transmitted over a single line by assigning each call to a specific time slot.
- **Digital Audio and Video Broadcasting**: TDM is used in broadcasting systems to transmit multiple audio or video streams over a single channel, ensuring efficient use of bandwidth.
- **Computer Networks**: TDM is used in network protocols and systems to manage the transmission of data from multiple sources over a single network medium.
### Advantages of TDM
- **Efficient Use of Bandwidth**: TDM all
TIME DIVISION MULTIPLEXING TECHNIQUE FOR COMMUNICATION SYSTEM
Design parameters to obtain al2 o3 nanofluid to enhance
1. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 02 Issue: 09 | Sep-2013, Available @ http://www.ijret.org 8
DESIGN PARAMETERS TO OBTAIN AL2O3 NANOFLUID TO ENHANCE
HEAT TRANSFER
Andreea Kufner1
1
Ph.D Student, Mechanical Engineering, Valahia University of Targoviste, Romania, kufner_georgiana@yahoo.com
Abstract
The study of nanostructures gained more and more ground in the past years due to the acceptable electrical conductivity, mechanical
flexibility and low cost manufacturing potential (mixing, mechanical stirring, ultrasonication, vacuum chambers).The process of
obtaining nanofluids with 0.1%, 0.5% and 1% concentration of aluminium oxide (Al2O3) was studied by mechanical stirring (in the
reactor station - static process equipment fitted with a stirring device in order to obtain solutions, emulsions, to make or to activate
chemical reactions and physic-chemical operations and to increase the heat exchange), vibrations and magnetic stirring. The selected
nanoparticles have an average size of 10 nm and were dispersed in base fluids consisting of distilled water and low concentration of
glycerin (5.4%, respectively 13%). The samples extracted during the process were analyzed with the quartz crystal microbalance
(QCM – modern alternative to analyze the complex liquids from water and copolymers to blood and DNA and the dynamic
viscoelasticity of fluids can be determined), in terms of homogenization and stability (behavior in time). Also, a heat transfer study
with the reactor station and a comparison between the heat transfer of the carrier fluid (consisting of water and 5.4% glycerin) and
the heat transfer of the antifreeze used in solar panels installations was conducted. This study showed a decrease of the time
consumed with heating the nanofluids and an improvement of the heat transfer due to the nanoparticles of Al2O3.
Index Terms: nanopowder, mechanical stirring, cluster, QCM, stability, sedimentation
-----------------------------------------------------------------------***-----------------------------------------------------------------------
1. INTRODUCTION
Nowadays, alumina is one of the most used oxides due to its
use in many areas such as thin film coatings, heat-resistant
materials, and advanced ceramic abrasive grains. Improved
devices using nanoscale structures requires the understanding
of thermal, mechanical electrical and optical properties of
nanostructures involved and also their manufacturing process.
The size of the nanoparticle defines the surface-volume ratio,
and for the same concentration, the suspension of particle size
would result in as small an area as possible to the interface
solid / liquid. Nanoparticle size affects the viscosity of
nanofluids. In general, viscosity increases as the concentration
of nanoparticles is increased. Studies on the suspension with
the same concentration of nanoparticles, but nanoparticles of
different sizes, have shown that the viscosity of the suspension
decreases as the nanoparticle size decreases. Particular
attention was given to the influence of nanoparticle size on
thermal conductivity concentration of nanofluids. As base
fluids have been used, in particular, distilled water, ethylene
glycol and propylene glycol and engine oil in which were
added nanoparticles in a concentration of less than 5% [1].
Increases of around 32% in thermal conductivity were
reported in case of nanofluids based on water and around 30%
of the ones based on ethylene glycol; in both cases a 4%
volume load of nanoparticles was used. Other researchers
reported that the thermal conductivity enhancement was
decreased as concentration increased from 6% to 10% [2]. The
same phenomena was observed also when the thermal
conductivity was increased as concentration increased from
2% to 10% [3], Al2O3 nanoparticles even though the particle
size was almost the same in both the cases. The great
disadvantage of larger nanoparticles is that suspensions tend to
become unstable. Experiments have shown that nanofluids
were able to enhance the thermal conductivity and convective
heat transfer by large margins [4]. Reducing particle size from
micro to nanometer, the development of new materials with
improved properties could be achieved and many researchers
reported results on nanoparticles dispersed in a viscous fluid
and on homogeneity [5], [6].
2. MATERIALS AND METHODS
2.1 Formulation of nanofluids
The reactive mixtures between two or more fluids are a vast
research field. The study of the optimal composition of heat or
cooling carriers from the solar water heating, from heat
exchangers, from cooling systems of engines and generators,
from thermal stations is a challenge because it must fulfill
some conditions, such as: high thermal transfer coefficient,
high specific heat (in case of heating carriers), no corrosion of
the pipes or metallic parts in contact etc. The most used heat
carriers are: burning gases, hot air, water vapors (steam), hot
water, engine oil, mineral oils and melted salts.
2. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 02 Issue: 09 | Sep-2013, Available @ http://www.ijret.org 9
The selected nanoparticles to obtain the nanofluid have an
average size of 10nm (according to the supplier’s
specifications), a specific surface of 160 m2
/gr and density of
3.7 gr/cm3
(Fig -1).
Fig -1: TEM image of Al2O3 nanoparticles
From the literature some information about the main
parameters that have influence on mixtures was selected
(temperature, speed and mixing time), and most of the
researchers report that nanoparticle’s dispersions in different
base fluids are made at maximum speed (depending on the
devices) [7] and at room temperature [8], [9] although there
are some studies that report the analyses of nanofluids at
different temperatures (20°C, 35°C and 50°C) [10]. When
referring to time, this varies a lot according to the amount of
nanofluid that is intended to be achieved [11], [12], [13] [14]
The shape of the reactor’s bottom can have a significant effect
on the hydrodynamic conditions inside it and hence the ability
to achieve a homogeneous suspension. Cylindrical shaped
tanks to lead to increased mass of particles in suspension by
eliminating areas that are “dead” at the intersection of the tank
wall. “Dead” areas or regions of segregation are found at the
intersection of walls, especially in flat-bottomed tanks [15].
The stirred tanks have many applications in the mechanical,
physical, chemical and biochemical processes where mixing is
important for the whole process performance, such as:
hydrodynamic operations (mixing, deposition, filtering,
washing, decanting, centrifuging), heat transfer operations
(heating, cooling, condensation, vaporization), mass transfer
operations (drying, distillation and rectifying, absorption and
adsorption, adsorption and desorption, crystallization,
sublimation).
The techniques used to achieve a homogeneous and stable in
time nanofluid are mechanical stirring, mechanical vibration
and magnetic stirring.
Mechanical stirring: distilled water together with glycerin and
nanopowder were mixed in the reactor station (Fig -2), firstly
at room temperature 21°C, and secondly at 50°C, maximum
rotational speed of 3300 rpm, for 2 hours. The withdrawn
samples were analyzed with the quartz microbalance – QCM
(Fig -3).
Fig -2: Reactor station with auxiliary heating system
1 – stirrer; 2 – float; 3 – inner recipient; 4 – mantle; 5 –
serpentine; 6 – temperature sensor; 7 – mixture evacuation
outlet; 8 – display; 9 – heat carrier outlet tap; 10 – supplying
and recirculation pump; 11 – inferior inlet; 12 – heat carrier
evacuation outlet; 13 – thermometer; 14 – heating unit; 15 –
superior inlet; 16 – heat carrier supplying inlet from mantle;
17 – profiled rail; 18 – cap; 19 – supplying pipeline; 20 – data
acquisition board and connections
The QCM (Fig -3), is an extremely sensitive sensor capable of
measuring mass changes in the spectrum of nanogram/cm2
.
The lowest detectable mass change is usually of a few ng/cm2
and is limited by the noise specifications of the crystal
oscillator and frequency counter resolution used to measure
frequency shifts [16].
The results show a decrease in the frequency shift and an
increase in the resistance which means that the quartz
microbalance is an outstanding device to analyze the fluid
properties.
3. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 02 Issue: 09 | Sep-2013, Available @ http://www.ijret.org 10
Fig -3: Quartz crystal microbalance
Mechanical vibration: from the reactor station, where the
mechanical stirring took place, 200ml nanofluid was
withdrawn and submitted to mechanical vibration for 2 hours.
The device for magnetic stirring consists of a motor that
rotates a disc on which two magnets are mounted. The disc
rotates the two magnets and these, in turn, are rotating
(stirring) the magnet from the nanofluid by attraction/rejection
leading to breakage of the possible clusters remained after
mechanical stirring and vibrations and to a better dispersion of
the nanoparticles in the base fluid. The device is connected to
a stabilized source that operates at maximum voltage of 12V
and hence the maximum power that can be achieved for
magnetic stirring is 60W. Information about the parameters
controlled and monitored during the process of obtaining the
nanofluids, is presented in Table -1.
Table -1: Samples withdrawn during the process of obtaining the nanofluids with 0.1%, 0.5% and 1%
volume concentration of Al2O3
No Sample Concentration Parameters
Wate
r [%]
Glyceri
n [%]
Al2O3
[%]
Mechanical Vibrations Magnetically
Rotational
speed
[rpm]
Temp.
[°C]
Time
[min]
Power[
W]
Time
[min]
Power
[W]
Time
[min]
1 NA-C1 94.55 5.35 0.1 3300 21 120 - - - -
2 NV-C1 94.55 5.35 0.1 - - - 3.12 120 - -
3 NM-C1 94.55 5.35 0.1 - - - - - 60 120
4 NAT-
C1
94.55 5.35 0.1 3300 50 120 - - - -
5 NVT-
C1
94.55 5.35 0.1 - - - 3.12 120 - -
6 NMT-
C1
94.55 5.35 0.1 - - - - - 60 120
7 NA-C2 86.13 13.38 0.5 3300 21 120 - - - -
8 NV-C2 86.13 13.38 0.5 - - - 3.12 120 - -
9 NM-C2 86.13 13.38 0.5 - - - - - 60 120
10 NAT-
C2
86.13 13.38 0.5 3300 50 120 - - - -
11 NVT-
C2
86.13 13.38 0.5 - - - 3.12 120 - -
12 NMT-
C2
86.13 13.38 0.5 - - - - - 60 120
13 NA-C3 85.88 13.13 1 3300 21 120 - - - -
14 NV-C3 85.88 13.13 1 - - - 3.12 120 - -
15 NM-C3 85.88 13.13 1 - - - - - 60 120
16 NAT-
C3
85.88 13.13 1 3300 50 120 - - - -
17 NVT-
C3
85.88 13.13 1 - - - 3.12 120 - -
18 NMT-
C3
85.88 13.13 1 - - - - - 60 120
4. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 02 Issue: 09 | Sep-2013, Available @ http://www.ijret.org 11
2.1 Analysis of nanofluids
The result of QCM analyses are presented graphically in
Charts 1 and 2.
• NA-C1: sample withdrawn from nanofluid with 0.1%
Al2O3 vol. concentration, after mechanical stirring at
21°C;
• NV-C1: sample withdrawn from nanofluid with 0.1%
Al2O3 vol. concentration, after mechanical vibration at
21°C;
• NM-C1: sample withdrawn from nanofluid with 0.1%
Al2O3 vol. concentration, after magnetic stirring at 21°C;
• NAT-C1:sample withdrawn from nanofluid with 0.1%
Al2O3 vol. concentration, after mechanical stirring at
50°C;
• NVT-C1: sample withdrawn from nanofluid with 0.1%
Al2O3 vol. concentration, after mechanical vibration at
50°C;
• NMT-C1sample withdrawn from nanofluid with 0.1%
Al2O3 vol. concentration, after magnetic stirring at 50°C;
For the nanofluid with 0.5% volume concentration Al2O3, C2
notation was used and for 1% volume concentration Al2O3, it
was used C3 notation.
Chart -1: Shift frequency depending on time for the nanofluid
with 0.1% vol. concentration of Al2O3, mechanically stirred at
21°C
Chart -2: Shift frequency depending on time, for three
nanofluids (volume concentrations of 0.1%, 0.5% and 1%
Al2O3, achieved by mechanical stirring, vibrations and
magnetic stirring at 21°C, respectively 50°C)
3. RESULTS AND DISCUSSION ON
FORMULATION AND ANALYSIS OF AL2O3
BASED NANOFLUIDS
The influence of increased concentration of nanoparticles can
be observed from the above chart. If in the case of nanofluid
with 0.1% vol. concentration of nanoparticles we did not
consider the curve for sample NA-C1 (mechanical stirring at
21°C) since it was unstable towards NAT-C1 (mechanical
stirring at 50°C), but for the nanofluid with 0.1% vol.
concentration Al2O3 a considerable improvement of QCM
oscillation damping phenomena can be observed for the
samples mechanically agitated in the reactor station.
The mechanical stirring of 0.1% concentration of Al2O3
nanopowder in a base fluid with 5.35% glycerin has not
influenced the homogenization process, on the contrary,
following the analyses, it was observed QCM oscillation
damping phenomena, which means the nanoparticles haven’t
been completely dispersed and their tendency is to form
sediments, hence clusters. Mechanical stirring at 50°C has a
positive influence over the homogeneity of nanofluid, but still
the higher temperature gives higher frequency shifts, which
means that the nanofluid has unstable areas. On the other
hand, a nanofluid submitted to mechanical vibrations,
regardless the temperature is homogenous, and at higher
temperatures the nanoparticles are better dispersed in the base
fluid, achieving an in-time stable nanofluid. As in the case of
water and 5.4% glycerin mixture the stability is observed
between ΔF=-170 Hz, ΔF=-130 Hz, and by adding 0.1%
Al2O3, this stability is observed between ΔF=-90 Hz, ΔF=-40
Hz. This confirms the selected techniques and also the settles
parameters to achieve the nanofluid.
If in the case of nanofluid with 0.1% vol. concentration of
nanoparticles the result for sample NA-C1 (mechanical
stirring at 21°C) was not considered, since it was unstable
towards NAT-C1 (mechanical stirring at 50°C), but for the
nanofluid with 0.1% vol. concentration Al2O3 a considerable
improvement of QCM oscillation damping phenomena can be
observed for the samples mechanically agitated in the reactor
station. But due to the positive values of the frequency shift
they cannot be considered homogenous neither stable in time
since the principle rules quartz crystal microbalance is based
on the fact that the amount of mixture applied to the surface of
the resonator is associated with the flow (movement) of the
fluid and thereby a decrease of frequency shift is observed.
The samples were submitted to visual analysis, from which we
can see the lack of homogeneity, due to sedimentation of
nanoparticles. These samples as well as some of the steps from
obtaining the nanofluid with 0.1% Al2O3 are shown in Fig -4
and for the nanofluid with 0.5% in Fig -5:
-3500000.00
-3000000.00
-2500000.00
-2000000.00
-1500000.00
-1000000.00
-500000.00
0.00
500000.00
0 22 42 62 82 102 122 142 162 182 202 222 242 262 282
ΔF[Hz]
Time [s]
Shift frequency [Hz] NA-C1
-200
-100
0
100
200
300
400
1 21 41 61 81 101 121 141 161 181 201 221 241 261 281
ΔF[Hz]
Time [s]
Shift frequency [Hz]
NA-C2
NA-C3
NV-C1
NV-C2
NV-C3
NM-C1
NM-C2
NM-C3
NAT-C1
NAT-C2
NAT-C3
NVT-C1
NVT-C2
NVT-C3
NMT-C1
NMT-C2
NMT-C3
5. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
__________________________________________________________________________________________
Volume: 02 Issue: 09 | Sep-2013, Available @ http://www.ijret.org 12
a) b)
c)
Fig -4: Achieving 0.1% vol. conc. Al2O3 nanofluid
a) NA-C1 sample extracted after mechanical stirring; b)
nanoparticle sedimentation after submission to vibrations; c)
nanofluid with 0.1% vol. conc. – 1 day after formulation
a) b)
Fig -5: Achieving 0.5% vol. conc. Al2O3 nanofluid
a) after extraction of sample NV-C2 and 2 hours after
extracting sample NA-C2; b) samples extracted from
nanofluid with 0.5% vol. conc. Al2O3
For the nanofluid with 1% vol. concentration, the quantities of
water and glycerin were decreased with 0.25% each and
similar evolution can be observed for the samples withdrawn
after the mechanical stirring at 21, respectively la 50°C from
the nanofluids with 0.5, respectively 1% Al2O3. But the
negative influence of the increased concentration of the
nanoparticles can also be observed. From the QCM analyses
no stabilization trend is visible for nearly all samples. It may
be noted that regardless of the concentration, a nanofluid
mechanically stirred at 50°C, which is then submitted to
mechanical vibrations has stable areas after 180s.
Fig -6 shows some of the samples containing 0.1%, 0.5% and
1% vol. conc. of Al2O3 after achieving the nanofluid with 1%
Al2O3:
a) b)
c)
Fig -6: Achieving 1% vol. conc. Al2O3 nanofluid
a) samples from nanofluids after mechanical stirring at 21°C,
from right to left: with 1% Al2O3 after formulation, with 0.5%
Al2O3 after one day after formulation, 0.1% Al2O3 two days
after formulation; b) samples from nanofluids submitted to
mechanical vibrations at 21°C, from right to left: with 1%
Al2O3 after formulation, with 0.5% Al2O3 after one day after
formulation, 0.1% Al2O3 two days after formulation;
c) samples from nanofluid with 1% vol. conc. of Al2O3 after
formulation
One can say that submitting a nanofluid to vibrations has a
very good influence on the homogeneity and stability in time
comparing to mechanic and magnetic stirring. Only
mechanical stirring is not sufficient to obtain a homogeneous
nanofluid and magnetic stirring is not totally breaking the
agglomerates formed, which affect stability of the nanofluids.
A higher temperature (in this case 50°C) has a better influence
on the stability of nanofluids comparing to the one obtained at
room temperature. Chart -3 shows the QCM results for the
three nanofluids on dispersion techniques (mechanical stirring,
vibrations and magnetic stirring at 21°C, respectively 50°C).
a)
-50
0
50
100
150
200
250
300
350
400
1 21 41 61 81 101 121 141 161 181 201 221 241 261 281
ΔF[Hz]
Time [s]
Shift frequency [Hz]
NA-C2
NA-C3
NAT-C1
NAT-C2
NAT-C3
6. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 02 Issue: 09 | Sep-2013, Available @ http://www.ijret.org 13
b)
c)
Chart -3: Shift frequency depending on time, for three
nanofluids (process type): a) mechanical stirring; b)
vibrations; c) magnetic stirring
The samples extracted for visual analysis were stored in dark
areas because strong light favors cluster formation. After two
– six weeks the samples are as in Fig -7:
a) b)
c) d)
e) f)
Fig -7: Samples extracted from the Al2O3 based nanofluids:
a) after one week of formulation; b) after two weeks of
formulation; c) after three weeks of formulation; d) after four
weeks of formulation; e) after five weeks of formulation; f)
after six weeks of formulation
4. ENHANCED HEAT TRANSFER ACHIEVED
WITH FIVE DIFFERENT CARRIERS
A simulation of the heat transfer achieved was done helped by
the reactor station. This simulation aims to evidence the heat
transfer in a solar collector. For this, the reactor station was
used to test five heat carriers (base fluid of the nanoparticles,
antifreeze and three nanofluids). During the experiments the
following parameters were monitored:
- time of heating the carrier in the auxiliary system, done
by the heating unit;
- time of heat transfer from carrier to water (through the
mantle’s walls);
- temperature of water and heat carrier during cooling off
The objective is a comparative analysis on the heat transfer
between heat carrier and water and then an evaluation of the
nanofluids’ performance having different concentrations of
nanoparticles. The results are compared with the ones obtained
in the same conditions for the mixture with 94.6% water and
-100
-80
-60
-40
-20
0
20
1 21 41 61 81 101 121 141 161 181 201 221 241 261 281
ΔF[Hz]
Time[s]
Shift frequency [Hz]
NV-C1
NV-C2
NV-C3
NVT-C1
NVT-C2
NVT-C3
-100
-80
-60
-40
-20
0
20
40
60
1 21 41 61 81 101 121 141 161 181 201 221 241 261 281
ΔF[Hz]
Time[s]
Shift frequency [Hz]
NM-C1
NM-C2
NM-C3
NMT-C1
NMT-C2
NMT-C3
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5.4% glycerin and the antifreeze used in solar panel
installations. During the experiments the reactor station was
used to determine the heat transfer of nanofluids with different
concentrations of nanoparticles. The inner recipient was filled
with 8 liters of water and the auxiliary system with 8 liters of
nanofluid with 0.1%, 0.5% and 1% vol. concentration of
nanoparticles (Fig -8). The nanofluids were heated with the
heating unit from 19°C to 50°C. The temperature displayed on
the thermometer of the auxiliary system was monitored.
Fig -8: Path of heat carrier from the auxiliary system to the
mantle
1 – superior connection; 2 – mantle; 3 – serpentine; 4 – heat
carrier evacuation outlet from the auxiliary heating system; 5 –
– heat carrier exhaust valve; 6 – supply and recirculation
pump; 7 – inferior connection to supply the mantle with heat
carrier; 8 – thermometer; 9 – inlet for the recovery of the heat
agent with low temperature from the mantle.
The first step of this experiment consists in heating the five
carriers (mixture with 94.6% water and 5.4% glycerin,
antifreeze used in solar panels installations and three
nanofluids with different volume concentrations of
nanoparticles); these were heated in the auxiliary system by
heating unit. The heating times for the five heat carriers are
shown graphically in Chart -4:
Chart -4: Heating times for five heat carriers (using the
heating unit)
As it can be seen in the above chart, the antifreeze heats in
approximately 14 minutes and the mixture in almost two-fold.
It can not specify with certainty the difference between
heating times of nanofluids with 0.1% and 0.5% Al2O3; they
are very close in value. Nanofluids with concentration of 1%
nanoparticles showed the least time for heating, which would
be very low power consumption when it is tested in the reactor
station, and a rapid rise in temperature by means of solar heat
rays for use in solar collectors. The heating process of the five
heat carriers is shown schematically in Fig -9:
Heat carrier–
NANO_0.1%
Heat carrier
NANO_0.1%
50°C
10m44s
Heat carrier–
NANO_0.5%
WATER
19°C
WATER
19°C
Heat carrier
NANO_0.5%
50°C
10m40s
Water
Mantle
Serpentine
Heat carrier-
mixture
Heating
unit
Heat carrier
mixture
50°C
30 min
WATER
19°C
Heat carrier–
NANO_1%
WATER
19°C
Heat carrier
NANO_1%
50°C
9m23s
Heat carrier-
antifreeze
Heat carrier
antifreeze
50°C
30 min
WATER
19°C
Water
Mantle
Serpentine
Heating
unit
Water
Mantle
Serpentine
Water
Mantle
Serpentine
Water
Mantle
Serpentine
Heating
unit
Heating
unit
Heating
unit
Fig -9: Heating times for five heat carriers
Regarding the heat transfer of the carriers to water in the
reactor station, through the mantle’s walls (both made out of
Veralite - transparent plates based on thermoplastic polyesters
produced by extrusion), it was recorded the duration until the
water reaches 50°C (thermodynamic equilibrium state
between water and heating)
00:10:44
00:10:40
00:09:23
00:30:00
00:14:14
00:00:00
00:02:53
00:05:46
00:08:38
00:11:31
00:14:24
00:17:17
00:20:10
00:23:02
00:25:55
00:28:48
00:31:41
00:34:34
19 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50
Heatingtimeofcarrier
(byheatingunit)[min]
Temperature [°C]
TEMP. NANO_0.1% [°C]
TEMP. NANO_0.5% [°C]
TEMP. NANO_1% [°C]
TEMP. MIXTURE [°C]
TEMP. ANTIFREEZE [°C]
8. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 02 Issue: 09 | Sep-2013, Available @ http://www.ijret.org 15
Chart -5: Heat transfer time of five heat carriers
From Chart -5 it can be seen that the nanofluid with highest
concentration of nanoparticles gives the fastest heat transfer.
Comparing to the mixture of water and 5.4% glycerin and with
the antifreeze, the heat transfer curves have a similar trend but
it can be observed the improvement in thermal transfer by
adding nanoparticles in a base fluid. The heat transfer process
is shown schematically in Fig -10:
50°CWATER
50°C
2h21min
Heat carrier–
NANO_0.1%
50°CWATER
50°C
2h12min
Heat carrier –
NANO_0.5%
50°CWATER
50°C
1h58min
Heat carrier –
NANO_1%
50°CWATER
50°C
2h21min
Heat carrier -
mixture
50°CWATER
50°C
2h12min
Heat carrier-
antifreeze
Water
Mantle
Serpentine
Heating
unit
Heat carrier -
mixture
Water
Mantle
Serpentine
Water
Mantle
Serpentine
Water
Mantle
Serpentine
Water
Mantle
Serpentine
Heating
unit
Heat carrier –
NANO_0.1%
Heat carrier-
antifreeze
Heating
unit
Heating
unit
Heat carrier–
NANO_0.5%
Heat carrier –
NANO_1%
Heating
unit
Fig -10: Heat transfer time of five heat carriers
After reaching the thermodynamic equilibrium state, I stopped
the recirculation and the heat carriers were left to cool off
during 2 hours and 20 minutes.
Keeping the water warm, but also the high temperature of the
heat carrier was best achieved using nanofluids with the
highest concentration of nanoparticles, as shown in Chart -6.
In all cases, the water temperature of the heat carriers
decreased faster than that of the water in the inner recipient of
the reactor station (Chart -6). When using nanofluids, in the
first 20 minutes of cooling, the water temperature rose with
one degree, something that didn’t happen when using water-
glycerin mixture or antifreeze. A nanofluid with minimum
concentration of 0.1% or 0.5% nanoparticles of Al2O3, behave
similarly in terms of maintaining the hot water in time. In turn,
1% concentration of nanoparticles has a positive influence on
the process of heat transfer. While a temperature of 43°C was
reached (the lowest of the three nanofluids), it kept hot water
at the highest temperature (39°C) during the cooling time (Fig
-11).
Chart -6: Time evolution of water temperature depending
on the temperature of five heat carriers (during cooling off
process)
36°C
2h20min
WATER
44°C
2h20min
Heat carrier–
NANO_0.1%
Heat carrier–
NANO_0.1%
37°C
2h20min
WATER
45°C
2h20min
Heat carrier–
NANO_0.5%
Heat carrier–
NANO_0.5%
39°C
2h20min
WATER
43°C
2h20min
Heat carrier–
NANO_1%
Heat carrier–
NANO_1%
36°C
2h20min
WATER
44°C
2h20min
Heat carrier-
mixture
37°C
2h20min
WATER
45°C
2h20min
Heat carrier-
antifreeze
Water
Mantle
Serpentine
Heating
unit
Water
Mantle
Serpentine
Water
Mantle
Serpentine
Water
Mantle
Serpentine
Water
Mantle
Serpentine
Heat carrier-
mixture
Heat carrier-
antifreeze
Heating
unit
Heating
unit
Heating
unit
Heating
unit
Fig -11: Time evolution of water temperature depending on
the temperature of five heat carriers
(during cooling off process)
02:21
02:12
01:58
02:48
03:21
00:00
00:28
00:57
01:26
01:55
02:24
02:52
03:21
03:50
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
Heattransfertimefromcarriertowater
(timeuntilthewaterreaches50°C)[h]
Water temperature [°C]
NANO_0.1%
NANO_0.5%
NANO_1%
MIXTURE
ANTIFREEZE
44°C
45°C
43°C
44°C
44°C
36°C
37°C
39°C
34°C
36°C
30
35
40
45
50
55
00:00
00:10
00:20
00:30
00:40
00:50
01:00
01:10
01:20
01:30
01:40
01:50
02:00
02:10
02:20
Temperatureofheatcarriers/water
(coolingoff)[°C]
Time[h]
TEMP.WATER(coolingwith
NANO_0.1%)
TEMP.WATER(coolingwith
NANO_0.5%)
TEMP.WATER(coolingwith
NANO_1%)
TEMP.WATER(coolingwith
mixture)
TEMP.WATER(coolingwith
antifreeze)
TEMP. NANO_0.1% [°C]
TEMP. NANO_0.5% [°C]
TEMP. NANO_1% [°C]
TEMP. MIXTURE [°C]
TEMP.ANTIFREEZE [°C]
9. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 02 Issue: 09 | Sep-2013, Available @ http://www.ijret.org 16
5. DISCUSSION ON ENHANCED HEAT
TRANSFER
In the second part of the article a comparative analysis of the
heat transfer between a heat carrier and water was made. We
followed the thermal transfer properties of the three nanofluids
carried out by the three techniques (mechanical stirring,
vibration, magnetic stirring) in comparison with the properties
of a mixture consisting of 5.4% glycerin and distilled water
and an anti-freeze used in the installation with solar panel. It
was found that adding an amount of nanoparticles in a heat
carrier has a significant influence on the heat transfer through
the walls of the reactor body mantle.
Thus, on heating the carriers by heating unit, the antifreeze
reached the temperature of 50°C in about 53% of the time in
which the mixture of water with 5.4% glycerin heated. But at
the time of starting the circulation pump the antifreeze
temperature dropped to 36°C, than that of the mixture dropped
to 40°C, and during the process of recirculation, the antifreeze
temperature stabilized again at 50°C slower than that of the
mixture, which is 29 minutes to 22 for the mixture.
In case of nanofluids, starting the recirculation has about the
same effect in terms of lowering the temperature and time of
stabilization, except that the nanofluid with the highest
concentration of nanoparticles (1%) stabilizes at 50°C in the
shortest time.
Taking into account that the nanofluid NANO_1% heats up
about 30% of the time in which is heated the mixture, namely
35% of the antifreeze heating time, we can say that a higher
concentration of nanoparticles dispersed in a carrier fluid, it
reduces time spent on heating.
Following the experiments, I found that the anti-freeze heats
more rapidly than the water-glycerin mixture, but the heat
transfer from the heating agent to the water is faster for the
water- glycerin mixture than in the case of the anti-freeze
(heats water in a time of 83% of the time in which antifreeze is
heating). As for maintaining the water hot water the water-
glycerin mixture and antifreeze behave the same.
In terms of heat transfer through the walls of the reactor’s
mantle, the antifreeze heated the water in 3 hours and 21
minutes. With reference to this figure, we can say again that
nanoparticles positively affect heat transfer. The simple
addition of 0.1% nanoparticles in a mixture of water with
5.4% glycerin, improved heat transfer with 16.07% as
compared to that of the carrier fluid and by about 30% than
that of the antifreeze. So, the higher amount of nanoparticles
in a nanofluid, the better heat transfer is.
6. CONCLUSIONS AND FURTHER RESEARCH
An extensive research on the parameters that influence the
homogeneity and stability of nanofluids was conducted using
distilled water with low concentration of glycerin, as base
fluid. Also, three dispersion techniques were applied in order
to avoid clusters formation.
Effect of concentration of nanoparticles, temperature,
rotational speed and mixing time were systematically
investigated. Finally, the samples were analyzed by means of
quartz crystal microbalance. The conclusions that can derive
from here are:
• Mechanical stirring is an important step in achieving
nanofluids by dispersing nanoparticles in a base fluid,
preferably with higher viscosity than of water but it is no
sufficient to obtain a homogenous and stable nanofluid.
• The process of vibrations has a very good influence on
dispersing ultra-fine nanoparticles in a base fluid. It also
influences the time-behavior of nanofluid.
• By dispersing the nanoparticles at a higher temperature
(in this case 50°C), a more stable nanofluid can be achieved.
• The base fluid with distilled water and 5.4% glycerin
does not favor the complete suspension of Al2O3
nanoparticles.
• Increasing glycerin concentration but also
nanoparticles, the samples extracted while making the
nanofluid with 05% volume concentration of Al2O3 has some
stable areas after 2 hours of vibrations at 21°C.
• Increasing nanoparticle concentration to 1% has a
negative influence on the stability and homogeneity of
nanofluid.
• Except the graph made for the samples extracted after
mechanical stirring at 21°C and after vibrations at 50°C, that
have a slight trend in stabilizing after 180s, the rest of the
samples show some frequency bounce which means that the
nanoparticles are settling, forms clusters which lead to an
inhomogeneous nanofluid.
• Due to the sedimentation observed after obtaining the
nanofluid with 0.1% Al2O3, for the next nanofluids with 0.5%,
respectively 1% Al2O3 the glycerin concentration was
increased to 13%.
The samples were stored for visual analysis (in a dark area in
order to avoid sedimentation) and it was observed a
sedimentation layer on the bottom of the sample bottles.
Due to the increasing concentration of nanoparticles the time
of heat transfer to the water in the reactor body decreased and
sedimentation problems and clusters formation were
diminished. In terms of maintaining hot water as long as
possible, following the experiments made using nanofluids
with the highest concentration of nanoparticles (NANO_1%),
led to a decrease of up to 39°C in 2 hours and 20 minutes to
the next tested heat carrier, with the best results at 37°C
(NANO_0.5%).
These novel and important findings issued from this work are
expected to provide useful recommendations to formulate
10. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 02 Issue: 09 | Sep-2013, Available @ http://www.ijret.org 17
stable nanofluids that could be used as heat carriers in solar
panel installations.
ACKNOWLEDGEMENTS
This work was supported by the Operational Programme for
Human Resources Development 2007-2013. Priority Axis 1
"Education and training in support of economical growth and
social development based on knowledge". Major area of
intervention 1.5. "Doctoral and postdoctoral programs in
support of research". Project title: "Doctoral preparing of
excellence for the knowledge society PREDEX".
POSDRU/CPP 107/DMI1.5/s/77497
REFERENCES
[1] V. Sridhara and L. N. Satapathy, "Al2O3-Based
Nanofluids: a review," Nanoscale Research Letters, ISSN:
1556-276X, vol. 6, p. 456, 2011.
[2] J. H. Lee, K. S. Hwang, S. P. Jang, B. H. Lee, J. H. Kim,
U. S. Choi Stephen and C. J. Choi, "Effective Viscosities and
Thermal Conductivities of Aqueous Nanofluids Containing
Low Volume Concentrations of Al2O3 Nanoparticles,"
International Journal of Heat and Mass Transfer, ISSN: 0017-
9310, vol. 51, no. 11-12, pp. 2651-2656, 2008.
[3] E. V. Timofeeva, A. N. Gavrilov, J. M. McCloskey and Y.
V. Tolmachev, "Thermal Conductivity and Particle
Agglomeration in Alumina Nanofluids: Experiments and
Theory," Physical review. E, Statistical, nonlinear, and soft
matter physics, ISSN: 1539-3755, vol. 76, no. 1, pp. 061203.1-
061203.16, 2007.
[4] S. Lee, U. S. Choi-Stephen, S. Li and J. A. Eastman,
"Measuring Thermal Conductivity of Fluids Containing Oxide
Nanoparticles," Journal of heat transfer, ISSN: 0022-1481,
vol. 121, no. 2, pp. 280-289, 1999.
[5] V. S. Kuptsov, "Motion Of A Spherical Solid Particle In A
Nonuniform Flow Of A Viscous Incompressible Liquid,"
Journal of Applied Mechanics and Technical Physics, pp. 510-
513, 1976.
[6] L. P. Pergushev and A. K. Rozentsvaig, "Effect Of
Inhomogeneity Of The Disperse Phase On Coalescence And
Mass-Transfer Processes In Liquid Emulsions," Journal of
Applied Mechanics and Technical Physics, pp. 495-501, 1980.
[7] X. Wang, X. Xu and U. S. Choi Stephen, "Thermal
Conductivity of Nanoparticle-Fluid Mixture," Journal of
thermophysics and heat transfer, ISSN: 0887-8722, vol. 13,
no. 4, pp. 474-480, 1999.
[8] M. P. Beck, Y. H. Yuan, P. Warrier and A. S. Teja, "The
effect of particle size on the thermal conductivity of alumina
nanofluids," Journal of Nanoparticle Research, ISSN: 1388-
0764, vol. 11, no. 5, pp. 1129-1136, 2009.
[9] S. Kaliyaperumal, S. Barghi, L. Briens, S. Rohani and J.
Zhu, "Fluidization Of Nano And Sub-Micron Powders Using
Mechanical Vibration," Particuology, p. 279–287, 2011.
[10] I. Tavman, A. Turgut, M. Chirtoc, H. P. Schuchmann and
S. Tavman, "Experimental Investigation of Viscosity and
Thermal Conductivity of Suspensions Containing Nanosized
Ceramic Particles," Archives of Materials Science and
Engineering, ISSN: 1897-2764, vol. 34, no. 2, pp. 99-104,
2008.
[11] P. C. Mukeshkumar, J. Kumar, S. Suresh and K. Praveen
babu, "Experimental Study on Parallel and Counter Flow
Configuration of a Shell and Helically Coiled Tube Heat
Exchanger Using Al2O3 / Water Nanofluid," Journal of
Materials and Environmental Science, ISSN: 2028-2508, vol.
3, no. 4, pp. 766-775, 2012.
[12] A. Jomphoak, T. Maturos, T. Pogfay, C. Karuwan, A.
Tuantranont și T. Onjun, „Enhancement of Thermal
Conductivity with Al2O3 for Nanofluids,” Journal of
Research and Applications in Mechanical Engineering, ISSN:
2229-2152, vol. 1, nr. 1, pp. 3-5, 2011.
[13] O. Zeitoun and M. Ali, "Nanofluid impingement jet heat
transfer," Nanoscale Research Letters, ISSN: 1556-276X, vol.
7, no. 139, pp. 1-13, 2012.
[14] D. W. Oh, A. Jain, J. K. Eaton, K. E. Goodson and J. S.
Lee, "Thermal Conductivity Measurement and Sedimentation
Detection of Aluminum Oxide Nanofluids by Using the 3ω
Method," International Journal of Heat and Fluid Flow, ISSN:
0142-727X, vol. 29, no. 5, pp. 1456-1461, 2008.
[15] A. Kufner, "New Reactor Body Development And
Functional Optimization Of The Station In Order To Obtain
Reactive Mixtures," in International Conference Proceedings
of PSRC, ISBN: 978-93-82242-15-4, Phuket, 2012.
[16] V. Cimpoca, C. Rădulescu, A. Stancu, I. Dulamă and D.
Leţ, Microbalanţa cu cristal de cuarţ. Metodă analitică.
Aplicaţii, Târgovişte: Bibliotheca, 2009.
BIOGRAPHIES
Andreea KUFNER obtained her bachelor's
degree from the Faculty of Material Science
and Mechanical Engineering in 2008. She is
currently a Ph. D. student and her research is
centered on the development of nanofluids and
the possibility of using Al2O3 based nanofluid in solar
collectors. She is main author for 11 research articles
published and presented in the last 3 years.