The document discusses nanofluids, which are colloidal suspensions of nanoparticles in a base fluid that can enhance heat transfer. Nanofluids are prepared by dispersing nanoparticles less than 100 nm in size, such as metals or metal oxides, in a base fluid like water. This improves the thermal conductivity and heat transfer properties compared to conventional fluids. Nanofluids have applications in areas where efficient heat transfer is important, such as automotive cooling, domestic heating/refrigeration, and industrial processes.
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
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
This document describes a study on incorporating discrete titanium dioxide (TiO2) nanotubes into polyethersulfone (PES) membranes using a non-solvent induced phase separation approach to modify the membranes. Different concentrations of TiO2 nanotubes were added to create nanocomposite membranes. Characterization showed the nanocomposite membranes had enhanced hydrophilicity and negative surface charge compared to unmodified PES membranes. Testing also found the TiO2 nanotube modified membranes had higher water flux, better organic matter rejection, and improved antifouling properties when filtering real wastewater compared to the unmodified PES membrane. Adding 1 wt% TiO2 nanotubes provided the best performance.
A review of imperative technologies for for waste water tratament 1Edgy Rod
This document summarizes five oxidation processes for wastewater treatment: cavitation, photocatalytic oxidation, Fenton's chemistry, ozonation, and hydrogen peroxide. It discusses the basics of each process, including optimal operating parameters and reactor design. The processes generate hydroxyl radicals that can oxidize many organic and inorganic compounds. While individually the processes can partially degrade compounds, a hybrid approach may be needed to fully treat wastewater and reduce toxicity to levels for further biological treatment. More research is still needed to scale up some technologies.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
IRJET- Membrane Separation Technology Applied in a Refrigeration CycleIRJET Journal
This document proposes modifying an absorption refrigeration cycle by using a membrane separation technology instead of vaporization separation. It would insert a hydrophobic membrane contactor to separate the refrigerant and absorbent through liquid-liquid extraction, reducing the high temperature heat required for vaporization. The membrane contactor uses hollow porous polypropylene fibers in a cartridge to generate a concentration gradient across the membrane, separating water with high solute concentration on one side from an organic solvent with low solute concentration on the other side. Preliminary results showed this membrane-based cycle could technically separate ethanol and acetaldehyde absorbed in water.
The Tianjin desalination plant in China constitutes a landmark project that integrates power production, seawater desalination, and edible salt production. IDE Technologies constructed a 100,000 m3/d multi-effect distillation plant within the area of a large coal-fired power station to provide boiler feed water and drinking water. The plant successfully operates under variable steam pressures from 0.3-6.0 bar and extreme ambient temperatures from -20°C to 40°C. The desalination plant produces high-quality drinking water and the brine is used to produce edible salt, providing an economic model of sustainable development that meets China's goals of a "Recycled Economy".
Vegetable oils in electrics transformers.IJERD Editor
the replacement of mineral dielectric oils by dielectric oils represent a case of improving environmental conditions failure vegetable oils have one much lower biodegradability and are prone to fewer accidents for its high resistance to ignition.
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
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
This document describes a study on incorporating discrete titanium dioxide (TiO2) nanotubes into polyethersulfone (PES) membranes using a non-solvent induced phase separation approach to modify the membranes. Different concentrations of TiO2 nanotubes were added to create nanocomposite membranes. Characterization showed the nanocomposite membranes had enhanced hydrophilicity and negative surface charge compared to unmodified PES membranes. Testing also found the TiO2 nanotube modified membranes had higher water flux, better organic matter rejection, and improved antifouling properties when filtering real wastewater compared to the unmodified PES membrane. Adding 1 wt% TiO2 nanotubes provided the best performance.
A review of imperative technologies for for waste water tratament 1Edgy Rod
This document summarizes five oxidation processes for wastewater treatment: cavitation, photocatalytic oxidation, Fenton's chemistry, ozonation, and hydrogen peroxide. It discusses the basics of each process, including optimal operating parameters and reactor design. The processes generate hydroxyl radicals that can oxidize many organic and inorganic compounds. While individually the processes can partially degrade compounds, a hybrid approach may be needed to fully treat wastewater and reduce toxicity to levels for further biological treatment. More research is still needed to scale up some technologies.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
IRJET- Membrane Separation Technology Applied in a Refrigeration CycleIRJET Journal
This document proposes modifying an absorption refrigeration cycle by using a membrane separation technology instead of vaporization separation. It would insert a hydrophobic membrane contactor to separate the refrigerant and absorbent through liquid-liquid extraction, reducing the high temperature heat required for vaporization. The membrane contactor uses hollow porous polypropylene fibers in a cartridge to generate a concentration gradient across the membrane, separating water with high solute concentration on one side from an organic solvent with low solute concentration on the other side. Preliminary results showed this membrane-based cycle could technically separate ethanol and acetaldehyde absorbed in water.
The Tianjin desalination plant in China constitutes a landmark project that integrates power production, seawater desalination, and edible salt production. IDE Technologies constructed a 100,000 m3/d multi-effect distillation plant within the area of a large coal-fired power station to provide boiler feed water and drinking water. The plant successfully operates under variable steam pressures from 0.3-6.0 bar and extreme ambient temperatures from -20°C to 40°C. The desalination plant produces high-quality drinking water and the brine is used to produce edible salt, providing an economic model of sustainable development that meets China's goals of a "Recycled Economy".
Vegetable oils in electrics transformers.IJERD Editor
the replacement of mineral dielectric oils by dielectric oils represent a case of improving environmental conditions failure vegetable oils have one much lower biodegradability and are prone to fewer accidents for its high resistance to ignition.
This technical seminar presentation discusses nanofluids, which are fluids containing nanometer-sized particles that can alter the heat transfer properties of base fluids. The document outlines various preparation methods for nanofluids, materials used, factors that influence thermal conductivity, advantages and limitations. It also discusses applications in electronics, transportation, industrial cooling and more. Nanofluids show potential as next-generation heat transfer fluids due to characteristics like higher thermal conductivity compared to conventional fluids.
Enhancement of rate of heat transfer using nanofluidsSharathKumar528
This document discusses the use of nanofluids for heat transfer applications. It defines nanofluids as fluids containing nanometer-sized particles that can enhance thermal conductivity. Metallic nanoparticles dispersed in water or ethylene glycol at low volumes increase the mixture's thermal conductivity over conventional fluids. The document outlines several factors that influence nanofluids' thermal properties, such as particle size and Brownian motion. It also describes methods for preparing different types of nanofluids and measuring their thermal conductivity using techniques like transient hot wire method. The document concludes with an experiment using titanium dioxide nanofluids as a coolant for car radiators.
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.
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.
Enhancement of rate of heat transfer using nano fluidsSharathKumar528
Nano fluids as coolants and lubricants is still very primitive in technology. This presentation explores the future of nano fluids for enhanced heat transfer.
This document reviews the preparation, properties, and applications of nanofluids. It discusses:
1) Methods for preparing nanofluids and factors that influence their stability and thermal properties.
2) Experimental and theoretical models that have been used to analyze the thermal conductivity and other properties of nanofluids. Many studies found thermal conductivity increased significantly with only small amounts of nanoparticles.
3) Potential applications of nanofluids in various industries where enhanced heat transfer is important, such as electronics, automobiles, and power plants. However, issues around nanofluid stability and production costs need further research before wide commercial use.
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.
iaetsd Nanofluid heat transfer a reviewIaetsd Iaetsd
This document summarizes research on using nanofluids to enhance heat transfer. Nanofluids are fluids containing nanosized particles that can increase the thermal conductivity of the base fluid. Several studies have found that nanofluids can increase heat transfer rates compared to the base fluid alone. The amount of heat transfer enhancement depends on factors like the nanoparticle material, size, concentration, and whether the fluid flow is laminar or turbulent. Nanofluids show potential for applications like cooling engines, electronics, and nuclear systems. However, issues like long-term stability, increased pumping power needs, and high production costs still need to be addressed for more widespread use of nanofluids in industries.
This document provides an introduction to nanofluids, which are fluids containing nanometer-sized solid particles that are engineered to enhance thermal conductivity. Conventional heat transfer fluids have inherently poor thermal conductivity, limiting their effectiveness. While adding micrometer-sized particles provided some improvement, nanofluids offer even better conductivity. Even at very low volumes of nanoparticles, nanofluids can exhibit up to 40% higher thermal conductivity than conventional fluids. This is due to nanoparticles having a high surface area to volume ratio and thermal properties an order of magnitude higher than base fluids. Their small size allows nanoparticles to behave similarly to base fluid molecules, avoiding issues like clogging and sedimentation seen with microparticles. Nanofluids' enhanced stability and thermal
Characterization of a flat plate solar water heating system using different n...Barhm Mohamad
Flat-plate solar collectors (FPSCs) are the most effective and environmentally friendly heating systems available. They are frequently used to convert solar radiation into usable heat for a variety of thermal applications. Because of their superior thermo-physical features, the use of Nano-fluids in FPSCs is a useful technique to improve FPSC performance. Nano-fluids are advanced colloidal suspensions containing Nano-sized particles that have been researched over the last two decades and identified a fluid composed of strong nanoparticles with a diameter of smaller than (100 nm). These micro-particles aid in improving the thermal conductivity and convective heat transfer of liquids when mixed with the base fluid. The current study provides an in-depth review of the scientific advances in the field of Nano-fluids on flat-plate solar collectors. Previous research on the usage of Nano-fluids in FPSCs shows that Nano-fluids can be used successfully to improve the efficiency of flat-plate collectors. Though several Nano-fluids have been reviewed as solar collector operatin fluids. Nano-fluids have greater pressure drops than liquids, and their pressure drops andhence pumping power rise as the volume flow rate increases. Additionally, the article discusses the concept of Nano-fluids, the different forms of nanoparticles, the methods for preparing Nano-fluids, and their thermos-physical properties. The article concludes with a few observations and suggestions on the usage of Nano-fluids in flat-plate solar collectors. This article summarizes the numerous research studies conducted in this region, which may prove useful for future experimental studies.
a brief presentation of increasing efficiency of refrigerants using nanotechnology. its main objective is to reduce other pollution effects produced due to refrigerants.
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.
IRJET - Concept of Nano Fluid in Heat Transfer Applications: A ReviewIRJET Journal
This document reviews the concept and applications of nanofluids in heat transfer. Nanofluids are fluids containing nanometer-sized solid particles that can enhance thermal conductivity and other properties. The document discusses how nanofluids can increase the efficiency of various thermal devices by increasing heat transfer rates. Specifically, it describes how nanofluids have been used to improve the performance of solar stills for desalination, heat exchangers, and solar collectors by increasing evaporation and heat transfer rates. The effectiveness of heat exchangers can be increased by 8% by using nanofluids instead of plain water as the cooling fluid. Overall, the document examines how nanofluids can lead to more effective utilization of energy and reduction of
This document reviews the concept and applications of nanofluids in heat transfer. Nanofluids are fluids containing nanometer-sized solid particles that can enhance thermal conductivity and other properties of base fluids like water and ethylene glycol. The document discusses how nanofluids increase properties like thermal conductivity, density, heat capacity and viscosity compared to base fluids. It also reviews applications of nanofluids in improving efficiency of solar stills, heat exchangers, solar collectors and other thermal systems. For example, the use of nanofluids in solar stills can increase their efficiency and water production rate by over 50%. In heat exchangers, nanofluids increase effectiveness from around 40% to over 90% by enhancing heat
A report on applications and challenges of nanofluidsSuvendu Roy
The document is a report on applications and challenges of nanofluids submitted by Sabuj Samanta. It discusses how nanofluids are produced by dispersing nanoparticles in base fluids like water or ethylene glycol. Nanofluids have higher thermal conductivity and heat transfer properties compared to base fluids alone. The report covers the preparation and properties of nanofluids, and their various applications in fields like solar energy collection, automotive cooling, electronics cooling, and medicine. It also discusses the economic aspects and costs associated with nanofluids.
Experimental investigation of cooling performance of an Automobile radiator u...IJERD Editor
This document summarizes an experimental study that investigated the cooling performance of an automobile radiator using an Al2O3-water+ethylene glycol nanofluid. Different volume fractions of Al2O3 nanoparticles between 0.01-0.08% were added to the base fluid and tested. The maximum heat transfer performance observed was a 48% increase over water for the 0.08% volume fraction nanofluid. Flow rates were also varied between 3-15 liters per minute, showing increased heat transfer with higher flow. The nanofluid had increased thermal conductivity compared to the base fluid, improving the radiator's cooling capacity.
CFD investigation on heat transfer enhancement in shell and tube heat exchang...IRJET Journal
The document discusses a computational fluid dynamics (CFD) investigation of heat transfer enhancement in a shell and tube heat exchanger using graphene oxide (GO) nanofluid. A 3D model of a shell and tube heat exchanger is developed and GO nanofluid is introduced. Governing equations are solved numerically to analyze heat transfer performance. Results show that incorporating GO nanofluid leads to enhanced heat transfer compared to traditional fluids due to GO's higher thermal conductivity and its ability to disrupt thermal boundary layers and promote mixing. Heat transfer rate increased 42% and convective heat transfer coefficient increased 62% with GO nanofluid. This suggests GO nanofluid can significantly improve heat exchanger efficiency for applications like power plants and HVAC systems. Further
Comparative analysis between traditional aquaponics and reconstructed aquapon...bijceesjournal
The aquaponic system of planting is a method that does not require soil usage. It is a method that only needs water, fish, lava rocks (a substitute for soil), and plants. Aquaponic systems are sustainable and environmentally friendly. Its use not only helps to plant in small spaces but also helps reduce artificial chemical use and minimizes excess water use, as aquaponics consumes 90% less water than soil-based gardening. The study applied a descriptive and experimental design to assess and compare conventional and reconstructed aquaponic methods for reproducing tomatoes. The researchers created an observation checklist to determine the significant factors of the study. The study aims to determine the significant difference between traditional aquaponics and reconstructed aquaponics systems propagating tomatoes in terms of height, weight, girth, and number of fruits. The reconstructed aquaponics system’s higher growth yield results in a much more nourished crop than the traditional aquaponics system. It is superior in its number of fruits, height, weight, and girth measurement. Moreover, the reconstructed aquaponics system is proven to eliminate all the hindrances present in the traditional aquaponics system, which are overcrowding of fish, algae growth, pest problems, contaminated water, and dead fish.
This technical seminar presentation discusses nanofluids, which are fluids containing nanometer-sized particles that can alter the heat transfer properties of base fluids. The document outlines various preparation methods for nanofluids, materials used, factors that influence thermal conductivity, advantages and limitations. It also discusses applications in electronics, transportation, industrial cooling and more. Nanofluids show potential as next-generation heat transfer fluids due to characteristics like higher thermal conductivity compared to conventional fluids.
Enhancement of rate of heat transfer using nanofluidsSharathKumar528
This document discusses the use of nanofluids for heat transfer applications. It defines nanofluids as fluids containing nanometer-sized particles that can enhance thermal conductivity. Metallic nanoparticles dispersed in water or ethylene glycol at low volumes increase the mixture's thermal conductivity over conventional fluids. The document outlines several factors that influence nanofluids' thermal properties, such as particle size and Brownian motion. It also describes methods for preparing different types of nanofluids and measuring their thermal conductivity using techniques like transient hot wire method. The document concludes with an experiment using titanium dioxide nanofluids as a coolant for car radiators.
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.
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.
Enhancement of rate of heat transfer using nano fluidsSharathKumar528
Nano fluids as coolants and lubricants is still very primitive in technology. This presentation explores the future of nano fluids for enhanced heat transfer.
This document reviews the preparation, properties, and applications of nanofluids. It discusses:
1) Methods for preparing nanofluids and factors that influence their stability and thermal properties.
2) Experimental and theoretical models that have been used to analyze the thermal conductivity and other properties of nanofluids. Many studies found thermal conductivity increased significantly with only small amounts of nanoparticles.
3) Potential applications of nanofluids in various industries where enhanced heat transfer is important, such as electronics, automobiles, and power plants. However, issues around nanofluid stability and production costs need further research before wide commercial use.
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.
iaetsd Nanofluid heat transfer a reviewIaetsd Iaetsd
This document summarizes research on using nanofluids to enhance heat transfer. Nanofluids are fluids containing nanosized particles that can increase the thermal conductivity of the base fluid. Several studies have found that nanofluids can increase heat transfer rates compared to the base fluid alone. The amount of heat transfer enhancement depends on factors like the nanoparticle material, size, concentration, and whether the fluid flow is laminar or turbulent. Nanofluids show potential for applications like cooling engines, electronics, and nuclear systems. However, issues like long-term stability, increased pumping power needs, and high production costs still need to be addressed for more widespread use of nanofluids in industries.
This document provides an introduction to nanofluids, which are fluids containing nanometer-sized solid particles that are engineered to enhance thermal conductivity. Conventional heat transfer fluids have inherently poor thermal conductivity, limiting their effectiveness. While adding micrometer-sized particles provided some improvement, nanofluids offer even better conductivity. Even at very low volumes of nanoparticles, nanofluids can exhibit up to 40% higher thermal conductivity than conventional fluids. This is due to nanoparticles having a high surface area to volume ratio and thermal properties an order of magnitude higher than base fluids. Their small size allows nanoparticles to behave similarly to base fluid molecules, avoiding issues like clogging and sedimentation seen with microparticles. Nanofluids' enhanced stability and thermal
Characterization of a flat plate solar water heating system using different n...Barhm Mohamad
Flat-plate solar collectors (FPSCs) are the most effective and environmentally friendly heating systems available. They are frequently used to convert solar radiation into usable heat for a variety of thermal applications. Because of their superior thermo-physical features, the use of Nano-fluids in FPSCs is a useful technique to improve FPSC performance. Nano-fluids are advanced colloidal suspensions containing Nano-sized particles that have been researched over the last two decades and identified a fluid composed of strong nanoparticles with a diameter of smaller than (100 nm). These micro-particles aid in improving the thermal conductivity and convective heat transfer of liquids when mixed with the base fluid. The current study provides an in-depth review of the scientific advances in the field of Nano-fluids on flat-plate solar collectors. Previous research on the usage of Nano-fluids in FPSCs shows that Nano-fluids can be used successfully to improve the efficiency of flat-plate collectors. Though several Nano-fluids have been reviewed as solar collector operatin fluids. Nano-fluids have greater pressure drops than liquids, and their pressure drops andhence pumping power rise as the volume flow rate increases. Additionally, the article discusses the concept of Nano-fluids, the different forms of nanoparticles, the methods for preparing Nano-fluids, and their thermos-physical properties. The article concludes with a few observations and suggestions on the usage of Nano-fluids in flat-plate solar collectors. This article summarizes the numerous research studies conducted in this region, which may prove useful for future experimental studies.
a brief presentation of increasing efficiency of refrigerants using nanotechnology. its main objective is to reduce other pollution effects produced due to refrigerants.
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.
IRJET - Concept of Nano Fluid in Heat Transfer Applications: A ReviewIRJET Journal
This document reviews the concept and applications of nanofluids in heat transfer. Nanofluids are fluids containing nanometer-sized solid particles that can enhance thermal conductivity and other properties. The document discusses how nanofluids can increase the efficiency of various thermal devices by increasing heat transfer rates. Specifically, it describes how nanofluids have been used to improve the performance of solar stills for desalination, heat exchangers, and solar collectors by increasing evaporation and heat transfer rates. The effectiveness of heat exchangers can be increased by 8% by using nanofluids instead of plain water as the cooling fluid. Overall, the document examines how nanofluids can lead to more effective utilization of energy and reduction of
This document reviews the concept and applications of nanofluids in heat transfer. Nanofluids are fluids containing nanometer-sized solid particles that can enhance thermal conductivity and other properties of base fluids like water and ethylene glycol. The document discusses how nanofluids increase properties like thermal conductivity, density, heat capacity and viscosity compared to base fluids. It also reviews applications of nanofluids in improving efficiency of solar stills, heat exchangers, solar collectors and other thermal systems. For example, the use of nanofluids in solar stills can increase their efficiency and water production rate by over 50%. In heat exchangers, nanofluids increase effectiveness from around 40% to over 90% by enhancing heat
A report on applications and challenges of nanofluidsSuvendu Roy
The document is a report on applications and challenges of nanofluids submitted by Sabuj Samanta. It discusses how nanofluids are produced by dispersing nanoparticles in base fluids like water or ethylene glycol. Nanofluids have higher thermal conductivity and heat transfer properties compared to base fluids alone. The report covers the preparation and properties of nanofluids, and their various applications in fields like solar energy collection, automotive cooling, electronics cooling, and medicine. It also discusses the economic aspects and costs associated with nanofluids.
Experimental investigation of cooling performance of an Automobile radiator u...IJERD Editor
This document summarizes an experimental study that investigated the cooling performance of an automobile radiator using an Al2O3-water+ethylene glycol nanofluid. Different volume fractions of Al2O3 nanoparticles between 0.01-0.08% were added to the base fluid and tested. The maximum heat transfer performance observed was a 48% increase over water for the 0.08% volume fraction nanofluid. Flow rates were also varied between 3-15 liters per minute, showing increased heat transfer with higher flow. The nanofluid had increased thermal conductivity compared to the base fluid, improving the radiator's cooling capacity.
CFD investigation on heat transfer enhancement in shell and tube heat exchang...IRJET Journal
The document discusses a computational fluid dynamics (CFD) investigation of heat transfer enhancement in a shell and tube heat exchanger using graphene oxide (GO) nanofluid. A 3D model of a shell and tube heat exchanger is developed and GO nanofluid is introduced. Governing equations are solved numerically to analyze heat transfer performance. Results show that incorporating GO nanofluid leads to enhanced heat transfer compared to traditional fluids due to GO's higher thermal conductivity and its ability to disrupt thermal boundary layers and promote mixing. Heat transfer rate increased 42% and convective heat transfer coefficient increased 62% with GO nanofluid. This suggests GO nanofluid can significantly improve heat exchanger efficiency for applications like power plants and HVAC systems. Further
Comparative analysis between traditional aquaponics and reconstructed aquapon...bijceesjournal
The aquaponic system of planting is a method that does not require soil usage. It is a method that only needs water, fish, lava rocks (a substitute for soil), and plants. Aquaponic systems are sustainable and environmentally friendly. Its use not only helps to plant in small spaces but also helps reduce artificial chemical use and minimizes excess water use, as aquaponics consumes 90% less water than soil-based gardening. The study applied a descriptive and experimental design to assess and compare conventional and reconstructed aquaponic methods for reproducing tomatoes. The researchers created an observation checklist to determine the significant factors of the study. The study aims to determine the significant difference between traditional aquaponics and reconstructed aquaponics systems propagating tomatoes in terms of height, weight, girth, and number of fruits. The reconstructed aquaponics system’s higher growth yield results in a much more nourished crop than the traditional aquaponics system. It is superior in its number of fruits, height, weight, and girth measurement. Moreover, the reconstructed aquaponics system is proven to eliminate all the hindrances present in the traditional aquaponics system, which are overcrowding of fish, algae growth, pest problems, contaminated water, and dead fish.
Use PyCharm for remote debugging of WSL on a Windo cf5c162d672e4e58b4dde5d797...shadow0702a
This document serves as a comprehensive step-by-step guide on how to effectively use PyCharm for remote debugging of the Windows Subsystem for Linux (WSL) on a local Windows machine. It meticulously outlines several critical steps in the process, starting with the crucial task of enabling permissions, followed by the installation and configuration of WSL.
The guide then proceeds to explain how to set up the SSH service within the WSL environment, an integral part of the process. Alongside this, it also provides detailed instructions on how to modify the inbound rules of the Windows firewall to facilitate the process, ensuring that there are no connectivity issues that could potentially hinder the debugging process.
The document further emphasizes on the importance of checking the connection between the Windows and WSL environments, providing instructions on how to ensure that the connection is optimal and ready for remote debugging.
It also offers an in-depth guide on how to configure the WSL interpreter and files within the PyCharm environment. This is essential for ensuring that the debugging process is set up correctly and that the program can be run effectively within the WSL terminal.
Additionally, the document provides guidance on how to set up breakpoints for debugging, a fundamental aspect of the debugging process which allows the developer to stop the execution of their code at certain points and inspect their program at those stages.
Finally, the document concludes by providing a link to a reference blog. This blog offers additional information and guidance on configuring the remote Python interpreter in PyCharm, providing the reader with a well-rounded understanding of the process.
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024Sinan KOZAK
Sinan from the Delivery Hero mobile infrastructure engineering team shares a deep dive into performance acceleration with Gradle build cache optimizations. Sinan shares their journey into solving complex build-cache problems that affect Gradle builds. By understanding the challenges and solutions found in our journey, we aim to demonstrate the possibilities for faster builds. The case study reveals how overlapping outputs and cache misconfigurations led to significant increases in build times, especially as the project scaled up with numerous modules using Paparazzi tests. The journey from diagnosing to defeating cache issues offers invaluable lessons on maintaining cache integrity without sacrificing functionality.
Batteries -Introduction – Types of Batteries – discharging and charging of battery - characteristics of battery –battery rating- various tests on battery- – Primary battery: silver button cell- Secondary battery :Ni-Cd battery-modern battery: lithium ion battery-maintenance of batteries-choices of batteries for electric vehicle applications.
Fuel Cells: Introduction- importance and classification of fuel cells - description, principle, components, applications of fuel cells: H2-O2 fuel cell, alkaline fuel cell, molten carbonate fuel cell and direct methanol fuel cells.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
CHINA’S GEO-ECONOMIC OUTREACH IN CENTRAL ASIAN COUNTRIES AND FUTURE PROSPECTjpsjournal1
The rivalry between prominent international actors for dominance over Central Asia's hydrocarbon
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Using Mackinder's Heartland, Spykman Rimland, and Hegemonic Stability theories, examines China's role
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Climate change's impact on the planet forced the United Nations and governments to promote green energies and electric transportation. The deployments of photovoltaic (PV) and electric vehicle (EV) systems gained stronger momentum due to their numerous advantages over fossil fuel types. The advantages go beyond sustainability to reach financial support and stability. The work in this paper introduces the hybrid system between PV and EV to support industrial and commercial plants. This paper covers the theoretical framework of the proposed hybrid system including the required equation to complete the cost analysis when PV and EV are present. In addition, the proposed design diagram which sets the priorities and requirements of the system is presented. The proposed approach allows setup to advance their power stability, especially during power outages. The presented information supports researchers and plant owners to complete the necessary analysis while promoting the deployment of clean energy. The result of a case study that represents a dairy milk farmer supports the theoretical works and highlights its advanced benefits to existing plants. The short return on investment of the proposed approach supports the paper's novelty approach for the sustainable electrical system. In addition, the proposed system allows for an isolated power setup without the need for a transmission line which enhances the safety of the electrical network
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...
Final report hmt
1. Page 1 of 15
INTRODUCTION:-
Heat transfer is one of the most important industrial processes. In any industrial facilities heat
must be efficiently managed by adding, removing or moving in the relevant sectors.
Conventional heat transfer fluids such as water, ethylene glycol (EG), pumping oil, etc, have not
shown sufficient capability for cooling applications due to their poor thermal performance.
Therefore, development of highly efficient heat transfer fluids for solving the drawback of
conventional fluids has become one of the most important priorities in the cooling industries. In
last decade, nanoscience and nanotechnology (NFs) has offered new solution by introducing
nanofluids (NFs) which may assist to enhance heat transfer fluids’ performance especially in the
high-tech applications.
Thermal properties of liquids play a decisive role in heating as well as cooling applications in
industrial processes. Thermal conductivity of a liquid is an important physical property that
decides its heat transfer performance. Nanofluids are stable colloidal suspensions of nano
materials (nanoparticles, nanorods, nanotubes, nanowires, nanofibers, nanosheets, other
nanocomposites, or even nano-droplets and nano-bubbles) in common, base fluids, such as
water, oil, ethylene-glycol mixtures (antifreeze), refrigerants, heat transfer fluids, polymer
solutions, bio-fluids, and others. Nanoparticles are very small, nanometer-sized particles with
their smallest dimension usually less than 100 nm (nanometers). The smallest nanoparticles, only
a few nanometers in diameter, may contain a few thousand atoms. These nanoparticles can
possess properties that are substantially different from their parent materials, and they may
interact quite differently within their dynamic molecular structure with the base fluids, than the
corresponding microparticles, and respond differently within different force-flux processes
accompanied with mass energy transfers. Similarly, nanofluids may have properties that are
substantially different from their base fluids, like much higher thermal conductivity, and other
flow and heat transfer characteristics. These advanced fluids have displayed potential to enhance
the performance of conventional heat transfer fluids. Nanofluids consist of a base fluid enriched
with nano size particles (less that 100 nm).
2. Page 2 of 15
Nanofluids are characterized by an enrichment of a base fluid like Water, Ethylene glycol or oil
with nanoparticles in variety of types like Metals, Oxides, Carbides, Carbon. Mostly commonly
recalled Nanofluids could be typified as TiO2 in water, CuO in water, Al2O3 in water, ZnO in
Ethylene glycol. Today Nanofluids have got wide range of applications in transportation, power
generation, nuclear, space, microelectronics, biomedical and many areas where heat removal is
involved.
By suspending nanophase particles in heating or cooling fluids, the heat transfer performance of
the fluid can be significantly improved. The main reasons may be listed as follows:
The suspended nanoparticles increase the surface area and the heat capacity of the fluid.
The suspended nanoparticles increase the effective (or apparent) thermal conductivity of
the fluid.
The interaction and collision among particles, fluid and the flow passage surface are
intensified.
The mixing fluctuation and turbulence of the fluid are intensified.
The dispersion of nanoparticles flattens the transverse temperature gradient of the fluid.
Nanofluid is a new kind of heat transfer medium, containing nanoparticles (1–100 nm) which are
uniformly and stably distributed in a base fluid. These distributed nanoparticles, generally a
metal or metal oxide greatly enhance the thermal conductivity of the nanofluid, increases
conduction and convection coefficients, allowing for more heat transfer. Nanofluids possess
the following advantages as compared to conventional fluids which makes them suitable
for various applications involving heat exchange.
Absorption of solar energy will be maximized with change of the size, shape, material,
and volume fraction of the nanoparticles.
The suspended nanoparticles increase the surface area and the heat capacity of the fluid
due to the very small particle size.
The suspended Nanoparticles enhance the thermal conductivity which results
improvement in efficiency of heat transfer systems.
Heating within the fluid volume, transfers heat to a small area of fluid and
allowing the peak temperature to be located away from surfaces losing heat to the
environment.
The mixing fluctuation and turbulence of the fluid are intensified.
The dispersion of nanoparticles flattens the transverse temperature gradient of the
fluid.
To make suitable for different applications, properties of fluid can be changed by
varying concentration of nanoparticles.
3. Page 3 of 15
PREPARATION OF NANOFLUIDS:-
A nanofluid is prepared by dispersing particles of metal or metal oxide with sizes of 100 nm or
less, in a base liquid such as water. The purpose of using nanofluids is to achieve higher values
of heat transfer coefficient compared with that of the base liquid. This is achieved by the
dispersion of solid particles, which have higher thermal conductivity than the base liquid. There
are many engineering applications that can benefit from the use of nanofluids, for example
absorption refrigeration, micro electromechanical systems, lubrication of automotive systems,
the manufacture of advanced miniature camera lenses, coolant in machining, automobile radiator
cooling, personal computers, solar water heating, heat exchangers, several medical applications,
nuclear reactors, and in several aerospace applications. Recent advances in material technology
have made it possible to produce innovative heat transfer fluids by suspending nanometer-sized
particles in base fluids, which could change the transport and thermal properties of the liquids.
Nanofluids represent solid-liquid composite materials consisting of solid nanoparticles with sizes
no larger than 100 nm suspended in liquid.
There are several methods to improve the heat transfer efficiency. Some methods are utilization
of extended surfaces, application of vibration to the heat transfer surfaces, and usage of micro
channels. Heat transfer efficiency can also be improved by increasing the thermal conductivity of
the working fluid. Commonly used heat transfer fluids such as water, ethylene glycol, and engine
oil have relatively low thermal conductivities, when compared to the thermal conductivity of
solids. High thermal conductivity of solids can be used to increase the thermal conductivity of a
fluid by adding small solid particles to that fluid.
It must be mentioned that, preparation of NFs is not only simple mixing and dispersing solid
particles in a base liquid. It is the most significant stage in the use of NPs or any nanostructured
materials to enhance the thermal characteristics of conventional heat transfer fluids. The reason
is that agglomeration of solid particles could happen in base liquid media if the NFs are not
prepared properly which may in turn result in poor thermo-physical property of NFs. There are
two major techniques, which are typically used for NFs preparation: two-step method and one-
step (single step) method-
1. Preparation of NFs via a two-step method:-
In the two-step method, which is the most commonly used technique, NPs, nanotubes, nanofibers
or any nanostructured materials are initially synthesized as dry powders via physical or chemical
methods. After that the synthesized dry powders are dispersed in base liquids. As solid
NPs/nanostructures have already been produced in industrial scale, this method is the best choice
to large scale production of NFs. However, because of high surface activity of particles,
agglomeration/aggregation of NPs is unavoidable. Hence, sedimentation of NPs can take place in
this method, which affects the NF’s properties negatively. This drawback (higher sedimentation
rate of NPs in the base liquid) in the two-step method has motivated the researchers to replace
this method with other technique to prepare NFs with minimum NPs agglomeration. For this
reason, preparation of NFs using one-step method has recently received notable attention.
4. Page 4 of 15
2. Preparation of NFs via a one-step method:-
In the one-step preparation method, both NP preparation and fabrication of NF are carried out
simultaneously in a combined process. Preparation of NF via a one-step method provides some
advantages such as minimizing the agglomeration of NPs because in this method the steps of
NPs drying, storage, transportation and dispersion of particles in the base liquid media are
combined which leads to minimum agglomeration/aggregation/sedimentation of NPs.
Nevertheless, scalability of some fabrication methods could be costly and troublesome
Stability of NFs:-
Stability is one of the key features for any NF system in each application, especially heat transfer
application. Although a lot of studies have been done about the stability of dispersion containing
solid particles, fabrication of homogeneous NFs with high stability is still a technical challenge.
There is a strong tendency of NPs to form aggregates/agglomeration in the liquid media resulting
in not only the clogging of microchannels but also degradation of NF’s thermal properties.
Therefore, the study of stability of NFs including the key factors which influence the stability as
well as the techniques which can be used for the evaluation of the stability of NFs are necessary.
The factors affecting stability of NFs-
Preparation method
Concentration of Nanoparticles
Mixing methods
Surface charge
FIG. 1. Preparation flow chart of nanofluids using different dispersing methods.
5. Page 5 of 15
MECHANISM OF ENHANCED HEAT CONDUCTION IN NANO
FLUIDS
In nano fluids heat is carried by phonons, i.e., by propagating lattice vibrations. Based on the
experimental results, we conclude that the macroscopic theory of heat transport in composite
materials fails for the case of nanofluids.
1. Brownian motion:-
Brownian motion, by which particle move through liquid and possibly collide, therby enabling
direct solid-solid transport of heat from one to another, can be expected to increase thermal
conductivity. This motion is characterized by the particle diffusion constant D, is given by the
Stokes-Einstien formula:
Where,
KB =Boltzmann constant,
d= paticle diameter
η = fluid viscosity
By the above equation we compare the thermal conductivity by comparing the time scale of
particle motion with that of heat diffusion in the liquid.
2.Effect of nanoparticle clustering
3.liquid layering at liquid/particle interface:-
6. Page 6 of 15
Fig-2 - Graph between thermal conductivity and diameter of particle size
THERMO-PHYSICAL PROPERTIES OF NANO FLUIDS
Thermo physical properties of the nanofluids are quite essential to predict their heat transfer
behavior. It is extremely important in the control for the industrial and energy saving
perspectives. There is great industrial interest in nanofluids. Nanoparticles have great potential to
improve the thermal transport properties compared to conventional particles fluids suspension,
millimetre and micrometer sized particles. In the last decade, nanofluids have gained significant
attention due to its enhanced thermal properties. Experimental studies show that thermal
conductivity of nanofluids depends on many factors such as particle volume fraction, particle
material, particle size, particle shape, base fluid material, and temperature. Amount and types of
additives and the acidity of the nanofluid were also shown to be effective in the thermal
conductivity enhancement.
The transport properties of nanofluid: dynamic thermal conductivity and viscosity are not only
dependent on volume fraction of nanoparticle, also highly dependent on other parameters such as
particle shape, size, mixture combinations and slip mechanisms, surfactant, etc. Studies showed
that the thermal conductivity as well as viscosity both increases by use of nanofluid compared to
base fluid. So far, various theoretical and experimental studies have been conducted and various
correlations have been proposed for thermal conductivity and dynamic viscosity of nanofluids.
However, no general correlations have been established due to lack of common understanding on
7. Page 7 of 15
mechanism of nanofluid. The thermal properties of nanofluids have received significant
attention. Nanofluids are considered to offer important advantages over conventional heat
transfer fluids.
1.Thermal conductivity:-
A wide range of experimental and theoretical studies were conducted in the literature to model
thermal conductivity of nanofluids. The existing results were generally based on the definition of
the effective thermal conductivity of a two-component mixture. The Maxwell (1881) model was
one the first models proposed for solid–liquid mixture with relatively large particles. It was
based on the solution of heat conduction equation through a stationary random suspension of
spheres. The effective thermal conductivity (Eq.1) is given by
………..(1)
Where kp -thermal conductivity of the particles,
keff -effective thermal conductivity of nanofluid,
kbf -base fluid thermal conductivity, and
ϕ(α) -volume fraction of the suspended particles.
Where,
m- number of the particles per unit volume and
dp- average diameter of the particles.
The general trend in the experimental data is that the thermal conductivity of nanofluids
increases with decreasing particle size. This trend is theoretically supported by two mechanisms
of thermal conductivity enhancement; Brownian motion of nanoparticles and liquid layering
around nanoparticles. However, there is also a significant amount of contradictory data in the
literature that indicate decreasing thermal conductivity with decreasing particle size. The thermal
conductivity of nanofluids was found to increase with concentration.
2. Viscosity:-
Compared with the experimental studies on thermal conductivity of nanofluids, there are limited
rheological studies reported in the literature for viscosity. Different models of viscosity have
been used by researchers to model the effective viscosity of nanofluid as a function of volume
fraction. Einstein (1956) determined the effective viscosity of a suspension of spherical solids as
8. Page 8 of 15
a function of volume fraction (volume concentration lower than 5%) using the phenomenological
hydrodynamic equations (Eq.2). This equation was expressed by-
………………………(2)
Where , µeff-effective viscosity of nanofluid,
µbf - base fluid viscosity, and
ϕ - volume fraction of the suspended particles.
Later, Brinkman (1952) presented a viscosity correlation (Eq.3) that extended Einstein’s
equation to suspensions with moderate particle volume fraction, typically less than 4%.
……………..(3)
The effect of Brownian motion on the effective viscosity in a suspension of rigid spherical
particles was studied by Batchelor (1977). For isotropic structure of suspension, the effective
viscosity was given by(Eq.4):
…………………….(4)
3. Specific heat and density:-
Using classical formulas derived for a two-phase mixture, the specific heat capacity and density
of the nanofluid as a function of the particle volume concentration and individual properties can
be computed using following equations(Eqs 5,and 6) respectively:
……………………..(5)
…………………………..(6)
4. Friction Factor :-
Turbulent friction factors have been evaluated for the flow of nanofluids in a tube, Some of the
studies are in agreement with values estimated by using the Blasius equation:
A number of studies concluded that heat transfer enhancement depends on the Dittus-Boelter
equation-
9. Page 9 of 15
where n is 0.4 at heating and 0.3 at cooling.
5.Temperature:-
The temperature of a two component mixture, such as a nanofluid, depends on the temperature of
the solid component as well as that of the host media. In a nanofluid the increase in temperature
enhances the collision between the nano particles (Brownian motion) and the formation of
nanoparticle aggregates (Li et al., 2008a), which result in a drastic change in the thermal
conductivity of nanofluids. It was found that thermal conductivity ratio decreased with
increasing temperature.
10. Page 10 of 15
APPLICATIONS OF NANOFLUIDS
1. Applications in automotive :-
An ethylene glycol and water mixture, the nearly universally used automotive coolant, is
a relatively poor heat transfer fluid compared to water alone.
In automobile arena, nanofluids have potential application as engine coolant,
automatic transmission fluid, brake fluid, gear lubrication, transmission fluid,
engine oil and greases.
The use of nanofluids as coolants would allow for smaller size and better positioning of
the radiators. There would be less fluid due to the higher efficiency, coolant pump
could be shrunk and truck engines could be operated at higher temperatures
allowing for more horsepower.
It was shown that the combustion of diesel fuel mixed with aqueous aluminum
nanofluid increased the total combustion heat while decreasing the concentration of
smoke and nitrous oxide in the exhaust emission from the diesel engine.
During the process of braking, the produced heat causes the brake fluid to reach its
boiling point, a vapour lock is created that retards the hydraulic system from
dispersing the heat caused from braking. Nanofluids with enhanced characteristics
maximize performance in heat transfer as well as remove any safety concerns.
2. Applications of nanofluid in domestic:-
Now a days, in refrigeration equipment HFC134a is used as a refrigerant. So
nanoparticles can be used to enhance the working fluid properties and energy efficiency
of the refrigerating system associated with reduction in CO2 emission.
Nanofluids can be applied in the building heating systems.
3. Industrial cooling applications:-
The application of nanofluids in industrial cooling will result in great energy savings and
emissions reductions. It was observed that the specific heat of nanofluids was found to be
50% higher for nanofluids compared with polyalphaolefin and it increased with
temperature. The thermal diffusivity was found to be 4 times higher for nanofluids. The
convective heat transfer was enhanced by ~10% using nanofluids compared with using
polyalphaolefin. The thermal conductivity of the liquid-metal fluid can be enhanced
through the addition of more conductive nanoparticles.
Due to higher density of chips, design of electronic components with more compact
makes heat dissipation more difficult. Advanced electronic devices face thermal
management challenges from the high level of heat generation and the reduction of
available surface area for heat removal. So, the reliable thermal management system is
vital for the smooth operation of the advanced electronic devices. Nanofluids with higher
thermal conductivities are predicated convective heat transfer coefficients compared to
those of base fluids.
11. Page 11 of 15
Due to the restriction of space, energy and weight in space station and aircraft, there is a
strong demand for high efficient cooling system with smaller size. Nanofluids with high
critical heat fluxes have the potential to provide the required cooling in such applications
as well as in other military systems, including military vehicles, submarines, and high-
power laser diodes. Therefore, nanofluids have wide application in space and defense
fields where power density is very high and the components should be smaller and weight
less.
4. Energy applications:-
For energy applications of nanofluids, two remarkable properties of nanofluids are utilized, one
is the higher thermal conductivities of nanofluids, enhancing the heat transfer, and another is the
absorption properties of nanofluids.
1.Energy storage:- The temporal difference of energy source and energy needs made necessary
the development of storage system. The storage of thermal energy in the form of sensible and
latent heat has become an important aspect of energy management with the emphasis on efficient
use and conservation of the waste heat and solar energy in industry and buildings. Latent heat
storage is one of the most efficient ways of storing thermal energy.
2. Solar absorption:- Solar energy is one of the best sources of renewable energy with minimal
environmental impact. The conventional direct absorption solar collector is a well established
technology, and it has been proposed for a variety of applications such as water heating; however
the efficiency of these collectors is limited by the absorption properties of the working fluid,
which is very poor for typical fluids used in solar collectors.
5. Mechanical applications:
Nanoparticles in nanofluids form a protective film with low hardness and elastic modulus on the
worn surface can be considered as the main reason that some nanofluids exhibit excellent
lubricating properties. Magnetic fluids are kinds of special nanofluids. Magnetic liquid rotary
seals operate with no maintenance and extremely low leakage in a very wide range of
applications, and it utilizing the property magnetic properties of the magnetic nanoparticles in
liquid.
1. Friction reduction:- Advanced lubricants can improve productivity through energy saving and
reliability of engineered systems. Tribological research heavily emphasizes reducing friction and
wear. Nanoparticles have attracted much interest in recent years due to their excellent load-
carrying capacity, good extreme pressure and friction reducing properties.
2. Magnetic sealing:- Magnetic fluids (Ferromagnetic fluid) are kinds of special nanofluids. They
are stable colloidal suspensions of small magnetic particles such as magnetite (Fe3O4). The
properties of the magnetic nanoparticles, the magnetic component of magnetic nanofluids, may
12. Page 12 of 15
be tailored by varying their size and adapting their surface coating in order to meet the
requirements of colloidal stability of magnetic nanofluids with non-polar and polar carrier
liquids. Ferro-cobalt magnetic fluid was used for oil sealing, and the holding pressure is 25 times
as high as that of a conventional magnetite sealing.
6. Biomedical application:
For some special kinds of nanoparticles, they have antibacterial activities or drug delivery
properties, so the nanofluids containing these nanoparticles will exhibit some relevant properties.
1.Antibacterial activity:- Organic antibacterial materials are often less stable particularly at high
temperatures or pressures. The antibacterial behaviour of ZnO nanofluids shows that the ZnO
nanofluids have bacteriostatic activity against, Further investigations have clearly demonstrated
that ZnO nanoparticles have a wide range of antibacterial effects on a number of other
microorganisms.
2. Nano drug delivery:- Over the last few decades, colloidal drug delivery systems have been
developed in order to improve the efficiency and the specificity of drug action [29]. The small
size, customized surface, improved solubility, and multi-functionality of nanoparticles open
many doors and create new biomedical applications. The novel properties of nanoparticles offer
the ability to interact with complex cellular functions in new ways .Gold nanoparticles provide
non-toxic carriers for drug and gene delivery applications.
7. Other applications:
Cancer Theraupetics.
Nanocryosurgery.
Sensing and Imaging
Cryopreservation Nanofluid Detergent.
Intensify micro reactors,
Nanofluids as vehicular brake fluids,
Nanofluids based microbial fuel cell,
Nanofluids as optical filters.
13. Page 13 of 15
LIMATATION OF USING NANOFLUIDS:-
The use of nanofluids seems attractive in a broad range of applications as reported in the
previous section. But the development in the area of nanofluid application is hindered by
many factors in which long term stability of nanofluid in suspension is major reason. So, this
paper focuses many important challenges that should be solved in the near future. The
following are the most pressing issues:
Poor long term stability of suspension
Increased pressure drop and pumping power
Lower specific heat
High cost of nanofluids
Toxicity and disposal problems
LITERATURE REVIEW
Suspension of nanoparticles like Al, Zn, Si etc. in base fluids are called nanofluids. Nanofluid is
the new challenge for thermal science provided by nanotechnology. These nanofluids have
unique features different from conventional solid liquid mixtures. They contain mm or
micrometer sized particles of metals and non-metals. Due to their excellent physical and
chemical characteristics they find wide applications in enhancing heat transfer.
1) Sarit Kumar Das, Stephen U.S. Choi & Hrishikesh E. Patel [1]presented a paper on
“Heat Transfer in Nanofluids-A Review”. In this paper they presented an exhaustive
review of nanotechnology study and suggest a direction for future developments in
nanotechnology. The conclusion drawn in this paper is that nanofluids show great promise
for use in cooling and related technologies. They observed maximum enhancement
(∼160%) with 1% volume fraction with multi-walled carbon nanotubes dispersed in
engine oil.
2) Elena V. Timofeeva, Wenhua Yu et. al. [2]presented a paper on “ Nanofluids for Heat
Transfer: An Engineering Approach”. In this paper the factors contributing to the fluid
cooling efficiency were discussed first, followed by a review of nanofluid engineering
parameters and a brief analysis of their contributions to basic thermo-physical properties.
3) P. Keblinski, S.R. Phillpot, S.U.S. Choi & J.A.Eastman [3]presented a paper on
“Mechanism of Heat Flow in Suspensions of Nano-sized Particles (nanofluids)”. In this
paper they explained different mechanisms of heat flow in nanofluids.They explained
Brownian motion of the particles, molecular level layering of the liquid at the
liquid/particle interface, the nature of heat transport in the nanoparticles, and the effects of
nanoparticle clustering.
4) S.U.S.Choi and J.A.Eastman[4] presented a paper on “Enhancing Thermal Conductivity
of Fluids with Nanoparticles”. They provided information related to technology for
production of nanoparticles and suspensions and theoretical study of thermal conductivity
14. Page 14 of 15
of nanofluids.They estimated potential benefits of nanofluids with copper nanophase
materials.
5) L.Xue, P. Keblinski, S.R.Phillot et. al.[5] presented a paper on “ Effect of liquid layering
at the liquid-solid interface on thermal transport”. In this paper they showed how the
ordering of the liquid at the liquid-solid interface affects the interfacial resistance. Their
simulation of a simple monoatomic liquid shwed no effect on the thermal transport either
normal to the surface or parralel to the surface. Also their findings suggest that the
experimentally observed large enhancement of thermal conductivity in suspension of solid
nanosized particles can not be explained by altered thermal transport proprties of the
liquid layer.
CONCLUSION
Nanofluid cooling has variety of application in power generation, industrial, information
technology, and business sections. Promising advantages of Nanofluids through enhancement of
heat transfer have been summarized as efficiency and safety boos in power generation, product
size, cost and waste reduction, product quality and aesthetic improvement, energy consumption
and emission reduction, faster communication and computation and ultimately in one word
prosperity of the society.
Finally dangerous and many unknown sides of the Nanofluids utilization must be addressed to
ensure about impressive role of this advanced technology in driving the life on planet earth
towards more prosperity. This end will be met thorough years of extensive research and
development of models, experiments and patents.
The review of these studies shows that nanofluids are very important for many applications.
Many studies showed good agreement between experimental and numerical studies. Some
general conclusions are:
An increase in thermal conductivity occurred by adding nanoparticles to liquids.
Viscosity increased as the concentration of particles increased.
Friction factor increased with Reynolds number from experimental results and from the
Blasius equation.
The convection heat transfer coefficient was shown to increase with Reynolds number
and volume concentration by experimental results and the Dittus-Boelter equation.
15. Page 15 of 15
REFERENCES
[1] Sarit Kumar Das, Stephen U.S. Choi & Hrishikesh E. Patel “Heat Transfer in Nanofluids-A
Review” Heat Transfer Engineering, Taylor & Fracis, 27(10):3-19, 2006.
[2] Elena V. Timofeeva, Wenhua Yu et. al. “Nanofluids for Heat Transfer: An Engineering
Approach”, Nanoscale Research Letters,pp.1-18,2003
[3] P. Keblinski, S.R. Phillpot, S.U.S. Choi & J.A.Eastman “Mechanism of Heat Flow in
Suspensions of Nano-sized Particles (nanofluids)”, International Journal of Heat and Mass
Transfer, 45 (2002) pp.855-863.
[4] S.U.S.Choi and J.A.Eastman “Enhancing Thermal Conductivity of Fluids with
Nanoparticles”, ASME International Mechanical Engineering Congress & Exposition, Nov. 12-
17,2005.
[5] L.Xue, P. Keblinski, S.R.Phillot et. al. “Effect of liquid layering at the liquid-solid interface
on thermal transport”, International Journal of Heat & Mass Transfer, 47 9,2004) 4277-4284.
[6] E Natarajan & R Sathish.,(2009), Role of nanofluids in solar water heater,
International Journal of Advanced Manufacturing Technology.
[7] M.T. Naik and L. Syam Sundar[11] published a paper “Investigation into Thermophysical
Properties of Glycol based CuO Nanofluids for Heat Transfer Applications” World Academy of
Science, Engineering and Technology 59,2011
[8] A.K.Singh, Defence Institute of Advanced Technology, Pune “Thermal Conductivity of
Nanofluids”, Defence Science Journal, Vol.58, No.5 Sep.2008,pp. 600-607.