The heat extraction problem is becoming an important factor in the development of micro-electronics. Over the last decade, micromachining technology has been increasingly used for the development of highly efficient cooling devices called heat sink because of its undeniable advantages such as less coolant demands and small dimensions. One of the most important micromachining technologies is micro channels. Hence, the study of fluid flow and heat transfer in micro channels which are two essential parts of such devices, have attracted more attentions with broad applications in both engineering and medical problems. Heat sinks are classified into single-phase or two-phase according to whether boiling of liquid occurs inside the micro channels
The microchannel heat sink is designed for electronic chips that could be effectively cooled by means of forced convection, by water flowing through the microchannels. This project presents a Computational Fluid Dynamics (CFD) flow simulation modeling, where water is made to flow across different cross-sectional microchannel heat sinks placed on heat source. The flow simulation of water and convective heat transfer are carried by using commercial software “Solid Works Flow Simulation”. In the CFD process stacked microchannels of various cross-sections viz., rectangular, triangular, pentagonal and circular are designed, then by defining the computational domain, boundary conditions as inlet mass flow (1e-5 kg/s),outlet pressure ( static pressure) and heat flux(750w/cm2) and by considering the parallel and counter flow direction of water in different cross-sectional microchannels the temperature drop in heat sink, pressure drop across the channels and amount of volumetric heat transfer coefficient are analyzed and compared.
This document discusses heat transfer in microchannels. It begins by defining microchannels as channels less than 1mm wide used for heat exchange. Microchannels allow for higher heat flux transfer due to their small size. They have various applications, especially in cooling electronics. The document outlines different channel designs, manufacturing methods, coolants used like nanofluids, and limitations of microchannels. It concludes that microchannels enable high heat flux transfer and have significant potential for further development.
Microchannel heat exchangers provide higher performance than conventional heat exchangers due to their small channel size which enables higher heat transfer coefficients and surface area to volume ratios. They also have manageable pressure drops due to distributed laminar flow through multiple short channels. Microchannel exchangers are fabricated using robust manufacturing methods like diffusion bonding and have been implemented and proven in applications like natural gas liquefaction plants and steam methane reforming where their compact size provides economic advantages.
This document summarizes a presentation on flow through microchannels. It introduces microchannels as channels less than 1 mm in hydraulic diameter and discusses their history, applications, and areas for further development. The presentation describes modeling single-phase flow through different microchannel designs using ANSYS Fluent software. It validates the models by comparing their thermal resistance values to experimental data from Tuckerman and Pease. The results show temperature, pressure, and viscosity variations along the microchannels' lengths for different flow parameters. The conclusion indicates temperature-dependent properties cause the Reynolds number term to diminish and discusses how flow rate and fins affect thermal resistance.
Micro-heat exchangers are heat exchangers where fluid flows in confined spaces less than 1 mm in dimensions. They have compact sizes, high heat transfer coefficients between 10,000-35,000 W/m2K, and high surface area to volume ratios of 20,000-30,000 m2/m3. Micro-heat exchangers are lighter weight and have lower costs than conventional heat exchangers. They can be modeled using computational fluid dynamics or tested experimentally to determine effectiveness, pressure loss, and other performance characteristics. Common fabrication methods include chemical etching, LIGA, and diffusion bonding.
This document summarizes a research paper on the thermal performance of air conditioners using nanofluids compared to base fluids. Key points:
- Nanofluids, which are liquids containing nanoparticles, can improve heat transfer in heat pipes and cooling systems due to their higher thermal conductivity compared to base fluids.
- The document reviews how factors like nanofluid type, nanoparticle size and concentration affect thermal efficiency and heat transfer limits. It also examines using nanofluids to enhance heat exchange in transmission fluids.
- An experimental setup is described to study heat transfer and friction factors of water-based Al2O3 nanofluids in a horizontal tube under constant heat flux. Temperature, pressure and flow rate are measured
IRJET- Double Pipe Heat Exchanger with Spiral FlowIRJET Journal
This document summarizes research on heat exchangers with parallel and counter flow configurations. It discusses how performance varies based on fluid properties and operating conditions. The document also outlines the experimental setup and procedure used to study a double pipe heat exchanger with a spiral inner tube. Tests were conducted with both parallel and counter flow arrangements to compare performance under different flow rates and inlet temperatures. Key findings from previous research on factors affecting heat transfer coefficients and effectiveness are also summarized.
IRJET- Numerical Investigation of the Forced Convection using Nano FluidIRJET Journal
This document summarizes research on using computational fluid dynamics (CFD) simulations to analyze heat transfer and friction factors for turbulent flow of titanium dioxide, iron oxide, and silicon dioxide nanofluid in semi-circle corrugated channels. The simulations were conducted at Reynolds numbers of 10,000-30,000, nanoparticle volume fractions of 0-6%, and constant heat flux conditions. Results showed that the Nusselt number, a measure of heat transfer, increased with higher nanoparticle volume fraction and Reynolds number. Maximum Nusselt number enhancement of 2.07 was found at a Reynolds number of 30,000 and volume fraction of 6%.
IRJET- Experimental Investigation of Heat Transfer Study in Rectangle Type St...IRJET Journal
The document experimentally investigates heat transfer in straight and obliquely finned microchannel heat sinks using water and nanofluids as coolants. Rectangle cross-section microchannels are studied at varying flow rates and heat inputs. Results show that a 0.1% concentration of Al2O3/water nanofluid provides the best heat transfer enhancement of 24.15% in the obliquely finned microchannel compared to water and SiO2/nanofluid. Overall, the obliquely finned microchannel provides 21.45% better heat transfer than the straight microchannel design. The study examines heat transfer and flow characteristics in microchannels to improve thermal management in electronics.
This document discusses heat transfer in microchannels. It begins by defining microchannels as channels less than 1mm wide used for heat exchange. Microchannels allow for higher heat flux transfer due to their small size. They have various applications, especially in cooling electronics. The document outlines different channel designs, manufacturing methods, coolants used like nanofluids, and limitations of microchannels. It concludes that microchannels enable high heat flux transfer and have significant potential for further development.
Microchannel heat exchangers provide higher performance than conventional heat exchangers due to their small channel size which enables higher heat transfer coefficients and surface area to volume ratios. They also have manageable pressure drops due to distributed laminar flow through multiple short channels. Microchannel exchangers are fabricated using robust manufacturing methods like diffusion bonding and have been implemented and proven in applications like natural gas liquefaction plants and steam methane reforming where their compact size provides economic advantages.
This document summarizes a presentation on flow through microchannels. It introduces microchannels as channels less than 1 mm in hydraulic diameter and discusses their history, applications, and areas for further development. The presentation describes modeling single-phase flow through different microchannel designs using ANSYS Fluent software. It validates the models by comparing their thermal resistance values to experimental data from Tuckerman and Pease. The results show temperature, pressure, and viscosity variations along the microchannels' lengths for different flow parameters. The conclusion indicates temperature-dependent properties cause the Reynolds number term to diminish and discusses how flow rate and fins affect thermal resistance.
Micro-heat exchangers are heat exchangers where fluid flows in confined spaces less than 1 mm in dimensions. They have compact sizes, high heat transfer coefficients between 10,000-35,000 W/m2K, and high surface area to volume ratios of 20,000-30,000 m2/m3. Micro-heat exchangers are lighter weight and have lower costs than conventional heat exchangers. They can be modeled using computational fluid dynamics or tested experimentally to determine effectiveness, pressure loss, and other performance characteristics. Common fabrication methods include chemical etching, LIGA, and diffusion bonding.
This document summarizes a research paper on the thermal performance of air conditioners using nanofluids compared to base fluids. Key points:
- Nanofluids, which are liquids containing nanoparticles, can improve heat transfer in heat pipes and cooling systems due to their higher thermal conductivity compared to base fluids.
- The document reviews how factors like nanofluid type, nanoparticle size and concentration affect thermal efficiency and heat transfer limits. It also examines using nanofluids to enhance heat exchange in transmission fluids.
- An experimental setup is described to study heat transfer and friction factors of water-based Al2O3 nanofluids in a horizontal tube under constant heat flux. Temperature, pressure and flow rate are measured
IRJET- Double Pipe Heat Exchanger with Spiral FlowIRJET Journal
This document summarizes research on heat exchangers with parallel and counter flow configurations. It discusses how performance varies based on fluid properties and operating conditions. The document also outlines the experimental setup and procedure used to study a double pipe heat exchanger with a spiral inner tube. Tests were conducted with both parallel and counter flow arrangements to compare performance under different flow rates and inlet temperatures. Key findings from previous research on factors affecting heat transfer coefficients and effectiveness are also summarized.
IRJET- Numerical Investigation of the Forced Convection using Nano FluidIRJET Journal
This document summarizes research on using computational fluid dynamics (CFD) simulations to analyze heat transfer and friction factors for turbulent flow of titanium dioxide, iron oxide, and silicon dioxide nanofluid in semi-circle corrugated channels. The simulations were conducted at Reynolds numbers of 10,000-30,000, nanoparticle volume fractions of 0-6%, and constant heat flux conditions. Results showed that the Nusselt number, a measure of heat transfer, increased with higher nanoparticle volume fraction and Reynolds number. Maximum Nusselt number enhancement of 2.07 was found at a Reynolds number of 30,000 and volume fraction of 6%.
IRJET- Experimental Investigation of Heat Transfer Study in Rectangle Type St...IRJET Journal
The document experimentally investigates heat transfer in straight and obliquely finned microchannel heat sinks using water and nanofluids as coolants. Rectangle cross-section microchannels are studied at varying flow rates and heat inputs. Results show that a 0.1% concentration of Al2O3/water nanofluid provides the best heat transfer enhancement of 24.15% in the obliquely finned microchannel compared to water and SiO2/nanofluid. Overall, the obliquely finned microchannel provides 21.45% better heat transfer than the straight microchannel design. The study examines heat transfer and flow characteristics in microchannels to improve thermal management in electronics.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
This document outlines a final year project on a water cooling system for a ship's engine. The project aims to show how important water cooling is for maintaining safe engine temperatures. It involves constructing a basic cooling system using inexpensive and accessible materials like aquarium pumps, bottles, and tubing within a 3 month timeframe with a budget of under $200. The system works by filtering, heating, and circulating fresh water to cool the engine via a heat exchanger before returning it to the water tank.
IRJET-Experimental Study on Helical Tube Heat Exchanger by Varying Cross Sect...IRJET Journal
This document presents an experimental study on a helical tube heat exchanger. The study varies the cross-section of the tubes by adding nano particles like TiO2 and SiO2 to the working fluid. The performance of a helical coil heat exchanger is analyzed and compared to a straight tube heat exchanger based on parameters like log mean temperature difference (LMTD), heat transfer coefficient, and Reynolds number. The results show that a helical coil heat exchanger with nano particles added to the working fluid is more efficient, with its overall heat transfer coefficient increasing with mass flow rate.
IRJET- Numerical Investigation on the Heat Transfer Characteristics of Alumin...IRJET Journal
This document presents a numerical investigation of heat transfer characteristics of a double pipe heat exchanger using alumina-water nanofluid. The study examines the effects of nanoparticle concentration and volume flow rate on heat transfer coefficient, Nusselt number, pressure drop, and friction factor. It was found that adding nanoparticles significantly improved the thermal performance of the heat exchanger. The average heat transfer coefficient and Nusselt number of the base fluid increased by 26% and 12.5% respectively with a 4% nanoparticle volume concentration. Nanoparticle addition also enhanced pressure drop by around 10.11%. Heat exchanger effectiveness could be improved by approximately 16% using a 4% alumina nanoparticle concentration in the base fluid.
Performance of water and diluted ethylene glycol as coolants for electronic c...IJERA Editor
As the number of transistors increases with new generation of microprocessor chips, the power draw and heat load to dissipate during operation increases. As a result of increasing the heat loads and heat fluxes the Conventional cooling technologies such as fan, heat sinks are unable to absorb and heat transfer excess heat dissipated by these new microprocessor. So, new technologies are needed to improve the heat removal capacity. In the present work single phase liquid cooling system with mini channel is analyzed and experimentally investigated. Mini channels are chosen as to provide higher heat transfer co-efficient than conventional channel. Copper pipes of 0.36 mm diameter are taken to fabricate heat sink and heat exchanger. A pump is used to circulate the fluid through heat sink and heat exchanger. A solid heated aluminium block to simulate heat generated electronic component is used and electrical input is supplied to the heated aluminium block and cooling system is placed over the heated block. The performance of the cooling system is analyzed from the experimental data obtained. It is experimentally observed that the mini channel liquid cooling system with water as a coolant has better performance than diluted ethylene glycol as coolant at different flow rates. The surface temperature of the heated aluminium block with convective heat transfer co-efficient is observed
Effect of nanofluid on heat transfer characteristics of double pipe heat exch...eSAT Journals
Abstract A nanofluid is a mixture of nano sized particles of size up to 100 nm and a base fluid. Typical nanoparticles are made of metals, oxides or carbides, while base fluids may be water, ethylene glycol or oil. The effect of nanofluid to enhance the heat transfer rate in various heat exchangers is experimentally evaluated recently. The heat transfer enhancement using nanofluid mainly depends on type of nanoparticles, size of nanoparticles and concentration of nanoparticles in base fluid. In the present paper, an experimental investigation is carried out to determine the effect of various concentration of Al2O3 nano-dispersion mixed in water as base fluid on heat transfer characteristics of double pipe heat exchanger for parallel flow and counter flow arrangement. The volume concentrations of Al2O3 nanofluid prepared are 0.001 % to 0.01 %. The conclusion derived for the study is that overall heat transfer coefficient increases with increase in volume concentration of Al2O3 nano-dispersion compared to water up to volume concentration of 0.008 % and then decreases. Keywords: Nanofluid, Heat Transfer Characteristics, Double Pipe Heat Exchagner, Al2O3 Nano-dispersion
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.
THE EFFECT OF GEOMETRICAL PARAMETERS ON HEAT TRANSFER AND HYDRO DYNAMICAL CHA...ijmech
Compact size and high heat transfer coefficient of helical coil heat exchangers causes them to have an
important role in various industrial applications. This paper investigate numerically on the influence of
different parameters such as coil radius, coil pitch and diameter of tube on the hydrodynamic and
heat transfer characteristics of helical double tube heat exchangers using the CFD software which is
based on the principles of heat transfer, fluid mechanics and thermodynamics. The results indicated that
heat transfer augmentation occurs by increasing of the inner Dean Number, inner tube diameter, curvature
ratio and by the reduction of the pitch of heat exchanger coil. By increasing the radius of coils, the
secondary flow effects due to centrifugal forces diminishes and flow of fluid through the coils tends to flow
in a straight path and as a result, the friction coefficient decreases consequently.
Design and Experimental Analysis of Rectangular Wavy Micro Channel Heat sinkAM Publications
An experimental investigation has been explore in order to study the flow of fluid and heat transfer characteristics on a Rectangular Wavy microchannel heat sink. Various applications are envisaged for the use of microchannel heat sink in electrical and electronic power generation and distribution. The Heat sink with microchannel is designed on an Aluminium specimen with Rectangular Wavy configuration with a channel cross section of 1mm x 0.5mm.To improve the heat transfer performance of the cooling system is achieved by using nanoparticles in the fluid passing through the microchannel heat sink. Results are presented by using different concentration (with 1% to 3%) of Nano fluids in water for the heat sink. Various cooling characteristics including thermal resistance, temperature drop and pressure drop across the microchannel heat sink are analysed for different volume concentrations, different volumetric flow rates and Reynolds number. Other significant characteristics for the measurement of heat transfer characteristics across this microchannel heat sink are also analysed and presented in this experiment.
Experimental Investigation of Vertical Downward Flow Boiling Heat Transfer i...IJMER
The present work is carried to determine the two phase heat transfer coefficient during flowing
vertical downward in the minichannel. The minichannel test section is made up of aluminum having
hydraulic diameter 1.33mm. The experiments were carried out by varying mass flow rate from 0.1g/sec to
0.3g/sec of steam at three different vapour qualities of 0.2, 0.4 and 0.6. The result showed as the heat flux
increases there is an increase in two phase heat transfer coefficient upto 20000W/m2 0C. In addition to
that there is a decrease in treand of heat transfer coefficient for vapour quality.
Presentation on air cum water cooler cpu kota majorasignmentRAVI PRAKASH CHAUHAN
This document summarizes a student project on developing an "Air cum water cooler". It includes an introduction describing the need for more energy efficient equipment. It then lists and describes the key components of the cooler such as the water distribution system, electrical motor, evaporator pads, fan, pump, water tank and cabinet. It explains the working principle involving heat transfer from inlet to outlet water. Some key benefits are that it saves both energy and costs compared to separate air and water coolers. Limitations are that it works best in low humidity areas. The conclusion emphasizes the importance of practical experience for students.
NUMERICAL ANALYSIS AND SIMULATION OF CONJUGATE HEAT TRANSFER STUDY OF ELECTRO...ijiert bestjournal
Present - day interest in the thermal analysis of electronic circuit boards arises mainly because of the failure of such components as a result of thermal fatigue. A thermal/structural ANSYS model was integrated in this study to enable the predictions of the temperature and stress distribution of vertically clamped parallel circuit boards that include series of symmetrically mounted heated electronic modules (chips). The board was modelled as a thin plate containing heated flush rectangular areas representing the heat generating modules. The ANSYS model was required to incorporate the effects of mixed convection on surfaces,heat generation in the modules,and conduction inside the board. Appropriate convection heat transfer coefficients and boundary condition s resulted in a temperature distribution in the board and chips. Then structural analyses were performed on the same finite element mesh with structural elements capable of handling orthotropic material properties. The stress fields were obtained and compa red for the two models possessing different fibers orientations .
This document describes a student project to design an air and water cooler in a single unit. It includes introductions to the components, materials, and working principle. The components include a water distribution system, electrical motor, evaporator pads, fan, pump, water tank, and cabinet. Water is distributed through holes and evaporates on the pads, cooling incoming air blown through by the fan. This design aims to reduce energy and cost compared to separate air and water coolers. It works best in dry, hot climates and has limitations in more humid conditions.
This document describes an experimental study of heat transfer in a rectangular duct with and without internal V-shaped ribs. Experiments were conducted with air flow in turbulent regime (Reynolds numbers 3000-18000) in smooth duct and ducts with continuous or discrete internal V-shaped ribs. Temperature and pressure measurements were taken to determine heat transfer coefficients and friction factors for different configurations. Results showed that continuous ribs enhanced heat transfer more than discrete ribs, but also increased pressure drop more substantially. Heat transfer enhancement was dependent on rib geometry and position.
This document discusses several methods for cooling power electronics including liquid cooling, air cooling, microchannel cooling, heat pipes, and jet impingement cooling. It also discusses using carbon nanotubes (CNTs) to improve polymer composites for applications in power electronics cooling. Microchannel cooling can provide high heat transfer coefficients but also high pressure drops. Heat pipes use phase change to passively circulate fluid for cooling. Jet impingement can provide high heat transfer but erosion may occur at high velocities. CNTs have excellent thermal and mechanical properties but achieving good dispersion in polymers is challenging.
Methods of Heat Dissipation in Laptops Using MEMSTyler Baker
This document discusses promising methods for laptop cooling using MEMS devices. It summarizes three primary MEMS cooling technologies: 1) Impinging jets, where micro-jets of air or fluid are used to directly cool hot surfaces through high-velocity impingement. 2) Heat exchangers and sinks, such as a closed-loop liquid cooling system with a microheat exchanger to efficiently transfer heat from circulating liquid. 3) Liquid cooling systems, though these take up more space than is suitable for laptops with current liquid cooling system designs. The document analyzes various studies on optimizing these approaches through nozzle design, array configurations, and microstructure engineering to maximize heat transfer rates while minimizing pressure drops and device sizes.
1) The document presents a computational study to determine heat transfer coefficients and friction factors for turbulent air flow through rectangular ducts with triangular ribs.
2) A commercial software package was used to simulate the flow and analyze heat transfer across the ribbed duct. The duct walls were modeled with and without ribs to compare heat transfer and pressure drop.
3) Results are presented in dimensionless form as Nusselt numbers and friction factors as functions of Reynolds number. It was found that the ribs increased both heat transfer and pressure drop compared to a smooth duct.
IRJET- Thermal Analysis of Corrugated Plate Heat Exchanger by using Ansys...IRJET Journal
This document discusses thermal analysis of a corrugated plate heat exchanger using ANSYS software through finite element analysis. It summarizes previous research on using nanofluids like Al2O3 in water to improve heat transfer in these types of heat exchangers. The document then outlines the methodology that will be used, which involves studying the corrugated plate heat exchanger with counterflow configuration and varying parameters like volume flow rate and corrugation angle to determine the optimal heat transfer results.
The document provides an overview of basics of HVAC (heating, ventilation and air conditioning) systems. It was prepared by Mohammed Abdul Mujeeb Khan, who has a B.Tech in Mechanical Engineering and P.G.D in Business Administration. The document discusses refrigerants, including common types like CFCs, HCFCs and HFCs. It also covers the refrigeration cycle and key components like the evaporator, condenser and compressor.
IRJET- A Review on Improvement of Heat Transfer Rate by Passive MethodsIRJET Journal
This document reviews research on improving heat transfer rates through passive methods. It discusses how adding nanoparticles to fluids to create nanofluids can improve heat transfer efficiency in heat exchangers. Several studies are summarized that found adding metal oxide nanoparticles like CuO and Al2O3 to water and ethylene glycol increased heat transfer rates compared to the base fluids alone. Corrugated plate heat exchangers in particular saw higher effectiveness with nanofluid use. However, more research is still needed to determine optimum nanoparticle concentrations for different nanofluids and applications. The aim of this review is to analyze how lower concentrations of Al2O3/water nanofluid could impact performance in plate heat exchangers.
EXPERIMENTAL ANALYSIS OF HEAT TRANSFER AND FLUID FLOW IN MICRO-CHANNEL HEAT SINKijmech
In this paper heat transfer in single phase through micro-channels was studied. The validation of classical correlations of conventional channels to micro-channels is explored. It is found that classical approach is in good agreement with the experimental results of heat transfer in micro-channels .The material used for micro-channel heat sink (MCHS) is copper, experiments were conducted using water as cooling agent in
this study. Micro-channels are made with the help of EDM machine on the upper surface of MCHS. Variation of heat transfer rates, effect of friction factor, effect of pressure drop and variation in temperature distribution is investigated in this study. It is observed in the study that with decrease in
velocity flow friction also decreases.
Thermal and fluid characteristics of three-layer microchannels heat sinksjournal ijrtem
ABSTRACT : A heat sink with three layers of microchannels with different flow arrangements has been studied numerically using CFD fluent software version 15. The different flow arrangements using uniform and divergence channels on thermal characteristics of heat sinks at the same mass flow rate are investigated. The results indicated that, uniform channels with counter-flow 1 arrangement provide the best temperature uniformity and divergence channels with counter flow gives the best heat sink performance.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
This document outlines a final year project on a water cooling system for a ship's engine. The project aims to show how important water cooling is for maintaining safe engine temperatures. It involves constructing a basic cooling system using inexpensive and accessible materials like aquarium pumps, bottles, and tubing within a 3 month timeframe with a budget of under $200. The system works by filtering, heating, and circulating fresh water to cool the engine via a heat exchanger before returning it to the water tank.
IRJET-Experimental Study on Helical Tube Heat Exchanger by Varying Cross Sect...IRJET Journal
This document presents an experimental study on a helical tube heat exchanger. The study varies the cross-section of the tubes by adding nano particles like TiO2 and SiO2 to the working fluid. The performance of a helical coil heat exchanger is analyzed and compared to a straight tube heat exchanger based on parameters like log mean temperature difference (LMTD), heat transfer coefficient, and Reynolds number. The results show that a helical coil heat exchanger with nano particles added to the working fluid is more efficient, with its overall heat transfer coefficient increasing with mass flow rate.
IRJET- Numerical Investigation on the Heat Transfer Characteristics of Alumin...IRJET Journal
This document presents a numerical investigation of heat transfer characteristics of a double pipe heat exchanger using alumina-water nanofluid. The study examines the effects of nanoparticle concentration and volume flow rate on heat transfer coefficient, Nusselt number, pressure drop, and friction factor. It was found that adding nanoparticles significantly improved the thermal performance of the heat exchanger. The average heat transfer coefficient and Nusselt number of the base fluid increased by 26% and 12.5% respectively with a 4% nanoparticle volume concentration. Nanoparticle addition also enhanced pressure drop by around 10.11%. Heat exchanger effectiveness could be improved by approximately 16% using a 4% alumina nanoparticle concentration in the base fluid.
Performance of water and diluted ethylene glycol as coolants for electronic c...IJERA Editor
As the number of transistors increases with new generation of microprocessor chips, the power draw and heat load to dissipate during operation increases. As a result of increasing the heat loads and heat fluxes the Conventional cooling technologies such as fan, heat sinks are unable to absorb and heat transfer excess heat dissipated by these new microprocessor. So, new technologies are needed to improve the heat removal capacity. In the present work single phase liquid cooling system with mini channel is analyzed and experimentally investigated. Mini channels are chosen as to provide higher heat transfer co-efficient than conventional channel. Copper pipes of 0.36 mm diameter are taken to fabricate heat sink and heat exchanger. A pump is used to circulate the fluid through heat sink and heat exchanger. A solid heated aluminium block to simulate heat generated electronic component is used and electrical input is supplied to the heated aluminium block and cooling system is placed over the heated block. The performance of the cooling system is analyzed from the experimental data obtained. It is experimentally observed that the mini channel liquid cooling system with water as a coolant has better performance than diluted ethylene glycol as coolant at different flow rates. The surface temperature of the heated aluminium block with convective heat transfer co-efficient is observed
Effect of nanofluid on heat transfer characteristics of double pipe heat exch...eSAT Journals
Abstract A nanofluid is a mixture of nano sized particles of size up to 100 nm and a base fluid. Typical nanoparticles are made of metals, oxides or carbides, while base fluids may be water, ethylene glycol or oil. The effect of nanofluid to enhance the heat transfer rate in various heat exchangers is experimentally evaluated recently. The heat transfer enhancement using nanofluid mainly depends on type of nanoparticles, size of nanoparticles and concentration of nanoparticles in base fluid. In the present paper, an experimental investigation is carried out to determine the effect of various concentration of Al2O3 nano-dispersion mixed in water as base fluid on heat transfer characteristics of double pipe heat exchanger for parallel flow and counter flow arrangement. The volume concentrations of Al2O3 nanofluid prepared are 0.001 % to 0.01 %. The conclusion derived for the study is that overall heat transfer coefficient increases with increase in volume concentration of Al2O3 nano-dispersion compared to water up to volume concentration of 0.008 % and then decreases. Keywords: Nanofluid, Heat Transfer Characteristics, Double Pipe Heat Exchagner, Al2O3 Nano-dispersion
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.
THE EFFECT OF GEOMETRICAL PARAMETERS ON HEAT TRANSFER AND HYDRO DYNAMICAL CHA...ijmech
Compact size and high heat transfer coefficient of helical coil heat exchangers causes them to have an
important role in various industrial applications. This paper investigate numerically on the influence of
different parameters such as coil radius, coil pitch and diameter of tube on the hydrodynamic and
heat transfer characteristics of helical double tube heat exchangers using the CFD software which is
based on the principles of heat transfer, fluid mechanics and thermodynamics. The results indicated that
heat transfer augmentation occurs by increasing of the inner Dean Number, inner tube diameter, curvature
ratio and by the reduction of the pitch of heat exchanger coil. By increasing the radius of coils, the
secondary flow effects due to centrifugal forces diminishes and flow of fluid through the coils tends to flow
in a straight path and as a result, the friction coefficient decreases consequently.
Design and Experimental Analysis of Rectangular Wavy Micro Channel Heat sinkAM Publications
An experimental investigation has been explore in order to study the flow of fluid and heat transfer characteristics on a Rectangular Wavy microchannel heat sink. Various applications are envisaged for the use of microchannel heat sink in electrical and electronic power generation and distribution. The Heat sink with microchannel is designed on an Aluminium specimen with Rectangular Wavy configuration with a channel cross section of 1mm x 0.5mm.To improve the heat transfer performance of the cooling system is achieved by using nanoparticles in the fluid passing through the microchannel heat sink. Results are presented by using different concentration (with 1% to 3%) of Nano fluids in water for the heat sink. Various cooling characteristics including thermal resistance, temperature drop and pressure drop across the microchannel heat sink are analysed for different volume concentrations, different volumetric flow rates and Reynolds number. Other significant characteristics for the measurement of heat transfer characteristics across this microchannel heat sink are also analysed and presented in this experiment.
Experimental Investigation of Vertical Downward Flow Boiling Heat Transfer i...IJMER
The present work is carried to determine the two phase heat transfer coefficient during flowing
vertical downward in the minichannel. The minichannel test section is made up of aluminum having
hydraulic diameter 1.33mm. The experiments were carried out by varying mass flow rate from 0.1g/sec to
0.3g/sec of steam at three different vapour qualities of 0.2, 0.4 and 0.6. The result showed as the heat flux
increases there is an increase in two phase heat transfer coefficient upto 20000W/m2 0C. In addition to
that there is a decrease in treand of heat transfer coefficient for vapour quality.
Presentation on air cum water cooler cpu kota majorasignmentRAVI PRAKASH CHAUHAN
This document summarizes a student project on developing an "Air cum water cooler". It includes an introduction describing the need for more energy efficient equipment. It then lists and describes the key components of the cooler such as the water distribution system, electrical motor, evaporator pads, fan, pump, water tank and cabinet. It explains the working principle involving heat transfer from inlet to outlet water. Some key benefits are that it saves both energy and costs compared to separate air and water coolers. Limitations are that it works best in low humidity areas. The conclusion emphasizes the importance of practical experience for students.
NUMERICAL ANALYSIS AND SIMULATION OF CONJUGATE HEAT TRANSFER STUDY OF ELECTRO...ijiert bestjournal
Present - day interest in the thermal analysis of electronic circuit boards arises mainly because of the failure of such components as a result of thermal fatigue. A thermal/structural ANSYS model was integrated in this study to enable the predictions of the temperature and stress distribution of vertically clamped parallel circuit boards that include series of symmetrically mounted heated electronic modules (chips). The board was modelled as a thin plate containing heated flush rectangular areas representing the heat generating modules. The ANSYS model was required to incorporate the effects of mixed convection on surfaces,heat generation in the modules,and conduction inside the board. Appropriate convection heat transfer coefficients and boundary condition s resulted in a temperature distribution in the board and chips. Then structural analyses were performed on the same finite element mesh with structural elements capable of handling orthotropic material properties. The stress fields were obtained and compa red for the two models possessing different fibers orientations .
This document describes a student project to design an air and water cooler in a single unit. It includes introductions to the components, materials, and working principle. The components include a water distribution system, electrical motor, evaporator pads, fan, pump, water tank, and cabinet. Water is distributed through holes and evaporates on the pads, cooling incoming air blown through by the fan. This design aims to reduce energy and cost compared to separate air and water coolers. It works best in dry, hot climates and has limitations in more humid conditions.
This document describes an experimental study of heat transfer in a rectangular duct with and without internal V-shaped ribs. Experiments were conducted with air flow in turbulent regime (Reynolds numbers 3000-18000) in smooth duct and ducts with continuous or discrete internal V-shaped ribs. Temperature and pressure measurements were taken to determine heat transfer coefficients and friction factors for different configurations. Results showed that continuous ribs enhanced heat transfer more than discrete ribs, but also increased pressure drop more substantially. Heat transfer enhancement was dependent on rib geometry and position.
This document discusses several methods for cooling power electronics including liquid cooling, air cooling, microchannel cooling, heat pipes, and jet impingement cooling. It also discusses using carbon nanotubes (CNTs) to improve polymer composites for applications in power electronics cooling. Microchannel cooling can provide high heat transfer coefficients but also high pressure drops. Heat pipes use phase change to passively circulate fluid for cooling. Jet impingement can provide high heat transfer but erosion may occur at high velocities. CNTs have excellent thermal and mechanical properties but achieving good dispersion in polymers is challenging.
Methods of Heat Dissipation in Laptops Using MEMSTyler Baker
This document discusses promising methods for laptop cooling using MEMS devices. It summarizes three primary MEMS cooling technologies: 1) Impinging jets, where micro-jets of air or fluid are used to directly cool hot surfaces through high-velocity impingement. 2) Heat exchangers and sinks, such as a closed-loop liquid cooling system with a microheat exchanger to efficiently transfer heat from circulating liquid. 3) Liquid cooling systems, though these take up more space than is suitable for laptops with current liquid cooling system designs. The document analyzes various studies on optimizing these approaches through nozzle design, array configurations, and microstructure engineering to maximize heat transfer rates while minimizing pressure drops and device sizes.
1) The document presents a computational study to determine heat transfer coefficients and friction factors for turbulent air flow through rectangular ducts with triangular ribs.
2) A commercial software package was used to simulate the flow and analyze heat transfer across the ribbed duct. The duct walls were modeled with and without ribs to compare heat transfer and pressure drop.
3) Results are presented in dimensionless form as Nusselt numbers and friction factors as functions of Reynolds number. It was found that the ribs increased both heat transfer and pressure drop compared to a smooth duct.
IRJET- Thermal Analysis of Corrugated Plate Heat Exchanger by using Ansys...IRJET Journal
This document discusses thermal analysis of a corrugated plate heat exchanger using ANSYS software through finite element analysis. It summarizes previous research on using nanofluids like Al2O3 in water to improve heat transfer in these types of heat exchangers. The document then outlines the methodology that will be used, which involves studying the corrugated plate heat exchanger with counterflow configuration and varying parameters like volume flow rate and corrugation angle to determine the optimal heat transfer results.
The document provides an overview of basics of HVAC (heating, ventilation and air conditioning) systems. It was prepared by Mohammed Abdul Mujeeb Khan, who has a B.Tech in Mechanical Engineering and P.G.D in Business Administration. The document discusses refrigerants, including common types like CFCs, HCFCs and HFCs. It also covers the refrigeration cycle and key components like the evaporator, condenser and compressor.
IRJET- A Review on Improvement of Heat Transfer Rate by Passive MethodsIRJET Journal
This document reviews research on improving heat transfer rates through passive methods. It discusses how adding nanoparticles to fluids to create nanofluids can improve heat transfer efficiency in heat exchangers. Several studies are summarized that found adding metal oxide nanoparticles like CuO and Al2O3 to water and ethylene glycol increased heat transfer rates compared to the base fluids alone. Corrugated plate heat exchangers in particular saw higher effectiveness with nanofluid use. However, more research is still needed to determine optimum nanoparticle concentrations for different nanofluids and applications. The aim of this review is to analyze how lower concentrations of Al2O3/water nanofluid could impact performance in plate heat exchangers.
EXPERIMENTAL ANALYSIS OF HEAT TRANSFER AND FLUID FLOW IN MICRO-CHANNEL HEAT SINKijmech
In this paper heat transfer in single phase through micro-channels was studied. The validation of classical correlations of conventional channels to micro-channels is explored. It is found that classical approach is in good agreement with the experimental results of heat transfer in micro-channels .The material used for micro-channel heat sink (MCHS) is copper, experiments were conducted using water as cooling agent in
this study. Micro-channels are made with the help of EDM machine on the upper surface of MCHS. Variation of heat transfer rates, effect of friction factor, effect of pressure drop and variation in temperature distribution is investigated in this study. It is observed in the study that with decrease in
velocity flow friction also decreases.
Thermal and fluid characteristics of three-layer microchannels heat sinksjournal ijrtem
ABSTRACT : A heat sink with three layers of microchannels with different flow arrangements has been studied numerically using CFD fluent software version 15. The different flow arrangements using uniform and divergence channels on thermal characteristics of heat sinks at the same mass flow rate are investigated. The results indicated that, uniform channels with counter-flow 1 arrangement provide the best temperature uniformity and divergence channels with counter flow gives the best heat sink performance.
This document summarizes a numerical study that analyzed fluid flow and heat transfer in a rectangular microchannel heat sink using ANSYS software. The study modeled a 10mm long substrate with a single rectangular microchannel that was 57μm wide and 180μm deep. Water was used as the cooling fluid. Governing equations for fluid flow, heat transfer, and the SIMPLE algorithm were used to simulate fluid flow and heat transfer in the microchannel. Results and discussion of the simulation are presented.
Applications Of Heat Transfer Enhancement Techniques A State-Of-The-Art ReviewSandra Long
This document provides a review of state-of-the-art heat transfer enhancement techniques. It discusses research on heat transfer fundamentals and applications. It covers various heat transfer techniques including the use of vortex generators, twisted tapes, ribs, and combined techniques. It shows that most compound techniques performed better than individual inserts for heat transfer augmentation. The document also reviews research on topics like compressible flows, channel flows, flow separation, and experimental methods for measuring heat transfer.
This document summarizes a study analyzing electronic chip microchannels using ANSYS software. It presents the background on microchannel cooling technology and prior research. It then describes the numerical model setup in ANSYS, including the microchannel geometry, governing equations, and boundary/flow conditions. Results are shown for temperature contours, velocity vectors, pressure drops, and heat transfer coefficients for different materials and pressure drops. The study found that outlet water temperature was highest for a pressure drop of 30 kPa and when the substrate was silicon. Overall, the document analyzes heat transfer in a microchannel heat sink using computational fluid dynamics software.
EXPERIMENTAL STUDY ON THE ANALYSIS OF HEAT ENHANCEMENT IN CORRUGATED TWISTED ...P singh
In heat exchanger, the enthalpy is transferred between two or more fluids, at different temperatures. The major challenge in designing a heat exchanger is to make the equipment more compact and achieve a high heat transfer rate using minimum pumping power. In recent years, the high cost of energy and material has resulted in an increased effort aimed at producing more efficient heat exchange equipment. Furthermore, as a heat exchanger becomes older, the resistance to heat transfer increases owing to fouling or scaling. The heat transfer rate can be improved by introducing a disturbance in the fluid flow thereby breaking the viscous and thermal boundary layer. However, in the process pumping power may increase significantly and ultimately the pumping cost becomes high. Therefore, to achieve a desired heat transfer rate in an existing heat exchanger at an economic pumping power, several techniques have been proposed in recent years and are discussed under the classification section.
In this work, a study of transient heat transfer in double tube heat exchanger has enhanced. The inner tube of the setup was made with corrugation on both inner and outer walls by twisting the pipe from one end, which gives the more swirling motion to the fluid particles flowing over it. The flow inside the pipe was considered as turbulent, and the analysis was done experimentally and theoretically by using the ANSYS workbench. The experimental results were compared with the experimental values taken in the setup done by considering the inner tube as normal pipe. In both heat exchangers the values were taken and compared with the theoretical analysis. Temperature distribution and heat transfer rate were calculated and the details of the study have been discussed in this paper.
Esign and thermal evaluation of shell and helical coil heat exchangereSAT Journals
Abstract
Heat exchangers are the important engineering equipments used for transferring heat from one fluid to another. Heat exchangers are widely used in various kinds of application such as power plants, nuclear reactors, refrigeration and air-conditioning systems, heat recovery systems, petrochemical, mechanical, biomedical industries. Helical coil heat exchangers are gaining wide importance now-a-days because it can give high heat transfer coefficient in small footprint of surface area. This paper focuses on the designing of shell and helical coil heat exchanger and its thermal evaluation with counter flow configuration. The thermal analysis is carried out considering the various parameters such as flow rate of cold water, flow rate of hot water, temperature, effectiveness and overall heat transfer coefficient.
Keywords— Helical coil heat exchanger, Counter flow, Flow rate, effectiveness, heat transfer coefficient etc.
CFD Analysis of a Double Pipe Heat Exchanger by using Fluid Based Nanomaterialsijtsrd
This document summarizes a study analyzing the heat transfer performance of different nanofluids (Al2O3, CuO, Fe3O4) flowing in a double pipe heat exchanger using computational fluid dynamics (CFD). The study examines the effects of nanofluid volume concentration (0.03%) and mass flow rate (8 Lpm, 10 Lpm) on heat transfer rate, pressure, temperature, and velocity distribution. The results show that Fe3O4 nanofluid provides the highest heat transfer rate at both flow rates compared to Al2O3 and CuO nanofluids. Specifically, at a flow rate of 10 Lpm and 0.03% concentration, Fe3O4 nanofluid achieves the
This document presents a numerical analysis of heat transfer enhancement in pipe-in-pipe helical coiled heat exchangers. A computational fluid dynamics (CFD) analysis was conducted to determine the effect of varying parameters like inner tube diameter, mass flow rates, and flow configuration (parallel vs. counter flow) on heat transfer characteristics. The CFD results showed that decreasing the inner tube diameter and increasing the mass flow rates led to higher overall heat transfer coefficients. Counter flow configuration provided better heat transfer than parallel flow. Validation of the CFD model showed decent agreement with existing empirical correlations for heat transfer in helical coils.
Numerical Analysis of Heat Transfer Enhancement in Pipe-inPipe Helical Coiled...iosrjce
This document presents a numerical analysis of heat transfer enhancement in pipe-in-pipe helical coiled heat exchangers. Computational fluid dynamics (CFD) was used to analyze the effect of varying parameters like inner tube diameter, mass flow rates, and flow configuration (parallel vs. counter flow). The results show that overall heat transfer coefficients increase with increasing inner Dean number and mass flow rates. Heat transfer rates also increase with higher inner mass flow rates. Counter flow configuration provides better heat transfer than parallel flow. Increasing the inner tube size decreases the total heat transfer rate due to a reduction in annulus cross-sectional area. Measured inner Nusselt numbers agree reasonably well with existing correlations.
This document presents a numerical analysis of heat transfer enhancement in pipe-in-pipe helical coiled heat exchangers. Computational fluid dynamics (CFD) was used to analyze the effect of varying parameters like inner tube diameter, mass flow rates, and coil configuration on heat transfer characteristics. The results show that overall heat transfer coefficient increases with increasing inner Dean number and decreasing inner tube diameter. Counter-flow configuration provides better heat transfer than parallel flow. Validation of CFD results was done using existing Nusselt number correlations from literature. Increasing tube size or annulus mass flow rate decreases the total heat transfer rate.
Suspended nanoparticles in conventional fluids,
called nanofluids, have been the subject of intensive study
worldwide since pioneering researchers recently discovered the
anomalous thermal behavior of these fluids. The heat transfer from
smaller area is achieved through microchannels. The heat transfer
principle states that maximum heat transfer is achieved in
microchannels with maximum pressure drop across it. In this
research work the experimental and numerical investigation for
the improved heat transfer characteristics of serpentine shaped
microchannel heat sink using Al2O3/water nanofluid is done. The
fluid flow characteristics is also analyzed for the serpentine
shaped micrchannel. The experimental results of the heat
transfer using Al2O3 nanofluid is compared with the numerical
values. The calculations in this work suggest that the best heat
transfer enhancement can be obtained by using a system with an
Al2O3–water nanofluid-cooled micro channel with serpentine
shaped fluid flow
Analysis of A Double Spiral Counter Flow Calorimeter in Impinging Flame Jet U...IJERA Editor
This document analyzes a double spiral counter flow calorimeter (DSCFC) using computational fluid dynamics (CFD). The DSCFC consists of two concentric spiral channels for fluid flow over a heated base plate, allowing for heat transfer between the solid and fluid. CFD simulations are performed using ANSYS-CFX to analyze heat transfer characteristics at varying Reynolds numbers and base temperatures. The results show heat transfer decreases with increasing Reynolds number but increases with higher base temperature. Pressure and temperature profiles within the DSCFC are also presented. In conclusion, the CFD analysis finds uniform pressure drop along the spiral channels except at the mid-length, with pressure and outlet temperature decreasing at higher Reynolds numbers.
Fvm Analysis for Thermal and Hydraulic Behaviour of Circular Finned Mpfhs by ...IJERA Editor
In this exploration the influence of using two types of Nano fluids (Ag-water and Al203-water) as a coolant at volumetric concentration is taken (c= 4%) in micro pin fin heat sink with circular fins in addition to the un-finned micro-channel heat sink is deliberated with the help of commercially available computational fluid dynamics software Fluent 14. The evaluation of flow and heat transfer characteristics of MPFHS and cooling fluids has been made under the similar boundary condition; at the range of Reynolds number used is (100-500). The gotten outcomes is exemplified that, Ag-water Nano fluid is gives the minimum pressure drop and slightly maximum heat transfer rate compared to Al203-water Nano fluid. And circular finned heat sink is dissipating more amount of heat compared to un-finned micro-channel heat sink. But it is also gives the maximum pressure drop due to finned area.
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
Analysis of Heat Transfer in Spiral Plate Heat Exchanger Using Experimental a...ijsrd.com
Heat transfer is the key to several processes in industrial application. In a present days maximum efficient heat transfer equipment are in demand due to increasing energy cost. For achieving maximum heat transfer, the engineers are continuously upgrading their knowledge and skills by their past experience. Present work is a skip in the direction of demonstrating the use of the computational technique as a tool to substitute experimental techniques. For this purpose an experimental set up has been designed and developed. Analysis of heat transfer in spiral plate heat exchanger is performed and same Analysis of heat transfer in spiral plate heat exchanger can be done by commercially procurable computational fluid dynamic (CFD) using ANSYS CFX and validated based on this forecasting. Analysis has been carried out in parallel and counter flow with inward and outward direction for achieving maximum possible heat transfer. In this problem of heat transfer involved the condition where Reynolds number again and again varies as the fluid traverses inside the section of flow from inlet to exit, mass flow rate of working fluid is been modified with time. By more and more analysis and experimentation and systematic data degradation leads to the conclusion that the maximum heat transfer rates is obtained in case of the inward parallel flow configuration compared to all other counterparts, which observed to vary with small difference in each section. Furthermore, for the increase heat transfer rate in spiral plate heat exchanger is obtain by cascading system.
Analytical and Experimental analysis ofthermal characteristics throughTriangu...IJERA Editor
Microscale heat transfer technique is widely intended for best cooling applications in electronic devices as high
heat transfer coefficients are achieved in microscale convection. In present study, analysis of thermal
characteristics has been carried out by analytical calculations along with experimental investigation for a straight
microchannel heat sink of equilateral triangular cross section of 173.21 μm hydraulic diameter with distilled
water as the working fluid. Designed Heater input watts and Reynolds number based on flow rate are varied for
optimized microchannel geometry. Experimental analysis is carried out under constant heat flux condition. The
microchannels are produced on highly accurate micro wire cut EDM. The Reynolds number is varied from 100
to 700. The major intension for this work is to enhance heat transfer coefficient and minimize pressure drop
across microchannel. The Reynolds number, temperature distribution, pressure distribution, heat transfer
coefficient, hydrodynamic entrance length, thermal entrance length, equivalent thermal resistances parameters
are calculated for microchannel heat sink performance analysis. The results of analytical calculations are verified
with experimental investigation. It is found that heat transfer coefficient and pressure drop increases with
increase in Reynolds numbers and decrease in microchannel heat sink hydraulic diameter. Also channel length is
directly proportional to temperature rise
Cfd and conjugate heat transfer analysis of heat sinks with different fin geo...eSAT Journals
This document discusses a computational fluid dynamics (CFD) and conjugate heat transfer analysis of different fin geometries for heat sinks used in electronics cooling. Five fin geometries - zigzag, fluted, slanted mirror, custom pin fin, and staggered array - were analyzed under different heat loads and air velocity. The results show that the slanted mirror geometry provided the best thermal performance with the lowest thermal resistance and highest heat transfer coefficient, while maintaining a relatively low pressure drop. CFD simulations using ANSYS Fluent were conducted to analyze fluid flow, heat transfer, temperature distribution, and thermal performance of the different heat sink designs.
This work deals with a study on the laminar convective heat flow of a homemade air condition ing unit through a computational fluid dynamics simulation. With adoption of chilled water as the working fluid within a tube section of the evaporative compartment of the homemade air conditioner whose radius is 5mm and Height 20mm .The numerical analysis was carried out using COMSOL MULTIPHYSICS.Simulation was carried out, using (276𝐾 (3°C) as the inlet temperature and 293𝐾 (20°C) as the outlet temperature with a flow rate of 0.15 m3 ⁄ s. The result showed the velocity profile of the working fluid and the temperature distribution before, during and after heat exchange, helping to achieve a Visual understanding of the Laminar convective fluid and heat flow phenomena within the cooling coil.
The results show that, with proper selection of physical parameters, significant heat transfer
enhancements and pressure drop reductions can be achieved simultaneously with porous pin fins and
the overall heat transfer performances in porous pin fin channels are much better than those in
traditional solid pin fin channels. The effects of pore density are significant. As PPI increases, the
pressure drops and heat fluxes in porous pin fin channels increase while the overall heat transfer
efficiencies decrease and the maximal overall heat transfer efficiencies are obtained at PPI 20.
Furthermore, the effects of pin fin form are also remarkable. With the same physical parameters, the
overall heat transfer efficiencies in the long elliptic porous pin fin channels are the highest while they
are the lowest in the short elliptic porous pin fin channels
Similar to DESIGN OF STACKED MICROCHANNEL HEAT SINKS USING COMPUTATIONAL FLUID DYNAMIC (20)
ACTIVE SAFETY CONTROL TECHNIQUE TO PREVENT VEHICLE CRASHINGP singh
Alertness during driving is a key aspect. Even a small distraction for the driver may lead to genuine mishaps. The possible reasons can be obstacle, inadequate vehicle control system or human reflexes (e.g. shock) during sudden distraction. Therefore "Active" and "Passive" systems for vehicle control play a significant role in automotive safety. In this paper, we have discussed an active control technique to prevent the vehicle from crashing. Three different cases of vehicle speed are considered. The presented technique is designed to evaluate the possibility of collision for both front and rear side. The control action will be taken for safe and smooth driving under different situations like parking, urban driving and highway driving.
Numerical Analysis of Engineered Steel Fibers as Shear Reinforcement in RC BeamsP singh
Using suitable fibers and additives in concrete to enhance its performance is an important consideration in the concrete industry with regard to the structural aspects of concrete. The purpose of this project is to investigate numerically the effectiveness of the engineered steel fiber as shear reinforcement in RC beams. Here steel fibers completely replaces the shear reinforcement (stirrups & links). The dimension of beam taken was 1000*150*150 mm with aspect ratio 80. The beams were reinforced with 10 mm steel bars as secondary reinforcement and 12 mm bars as main reinforcement on the tension side. Numerical analysis using ANSYS R16.1 software package was carried out. The load-deflection curves for the beams with different dosage of fibers were drawn superimposing their numerical values. Initially, in all three cases the curve was linear elastic and about 80% of ultimate load they tend to be non-linear. It was observed that there was fair agreement between the results which indicates some favourable aspects concerning the use of steel fibres as shear reinforcement in concrete beams. It was investigated that the inclusion of steel fibres (Hook End Type) improves the shear strength of RC beams without stirrups by improving the matrix between concrete and steel fibers. Thus this project focuses in the design and analysis using the software ANSYS R16.1 for an alternative steel reinforcement with better or equivalent performance.
TRANSIENT ANALYSIS OF PIEZOLAMINATED COMPOSITE PLATES USING HSDTP singh
Piezoelectric materials have excellent sensing and actuating capabilities have made them the most practical smart materials to integrate with laminated structures. Integrated structure system can be called a smart structure because of its ability to perform self-diagnosis and quick adaption to environment changes. An analytical procedure has been developed in the work based on higher order shear deformation theory subjected to electromechanical loading for investigating transient characteristics of smart material plates. For analysis two displacement models are to be considered i.e., model-1 accounts for strain in thickness direction is zero whereas in model-2 in-plane displacements are expanded as cubic functions of the thickness coordinate. Navier’s technique has been adopted for obtaining solutions of anti-symmetric cross–ply and angle-ply laminates of both model-1 and model-2 with simply supported boundary conditions. For obtaining transient response of a laminated composite plate attached with piezoelectric layer Newmark’s method has been used. Effect of thickness coordinate of composite laminated plates attached with piezoelectric layer subjected to electromechanical loadings is studied.
ARTISANAL BOATBUILDING IN BRAZILIAN SHORES: CRAFTSMEN, BOATYARDS, AND MANUFAC...P singh
The majority of Brazilian small craft fishing fleet comes from artisanal boatyards which struggles with market pressure, professional social devaluation, and lack of raw materials. This work aims to provide a description about small craft artisanal boatbuilding in Brazilian shores to support initiatives to increase its social, economical, and environmental sustainability. On site visits and interviews about craftsmen social-economics; boatyards’ production organization; and manufacturing processes’ technological aspects were conducted. Results show that craftsmen are characterized by reasonable income and livelihood degree, compared with workers of similar educational level in their region. Relationships and work organization among them is traditionally structured and community based. Boatyards have sufficient structure, though access to new technologies and resources could be increased. Observed plank on frame building technique depends on workforce skills, commitment, and knowledge, as well as the resulting boats’ design and performance. Small craft artisanal boatbuilding is a living sector with its own dynamics, subjected to the creation and eventual adoption of new technologies. Instead of replacing the current manufacturing process by fibreglass reinforced polymer laminates, as suggested by some initiatives, it is believed that this sector’s sustainability can be increased by gradual introduction of tools, materials, and techniques while preserving its artisanal characteristics and qualities.
DESIGN AND FABRICATION OF THERMO ACOUSTIC REFRIGERATORP singh
In an age of impending energy and environmental crises, current cooling technologies continue to generate greenhouse gases with high energy costs. Thermo acoustic refrigeration is an innovative alternative for cooling that is both clean and inexpensive.
Thermo acoustic refrigerators are systems which use sound waves and a non-flammable mixture of inert gases to generate refrigeration effect. The main components are a closed cylinder, an acoustic driver, a porous component called a stack, and two heat-exchangers. Application of acoustic waves through the driver makes the gas resonant. As the gas oscillates back and forth, it creates a temperature difference along the length of the stack. This temperature change is due to compression and expansion of the gas by the sound pressure and the rest is a consequence of heat transfer between the gas and the stack. The temperature difference is used to remove heat from the cold side and reject it at the hot side of the system, producing cooling.
FIELD AND THEORETICAL ANALYSIS OF ACCELERATED CONSOLIDATION USING VERTICAL DR...P singh
Mumbai is the region consisting of soft compressible marine clay deposits. There are several construction problems on such soils and thus ground improvement is need to be carried out. Vertical drains is generally preferred technique as accelerated settlement is achieved during the construction phase itself if planned accordingly. The concept of vertical drains is based on the theory of three dimensional consolidation as described by Terzaghi (1943). Based on this concept, a consolidation programme is developed and an attempt is made to determine the field to laboratory coefficient of vertical consolidation ratio by Taylor’s Square Root of Time Method and Casagrande’s Logarithm of Time Fitting Method for this region by considering the case study of Bhandup Lagoon Works Embankment. Based on this ratio, the rate of consolidation and time required for consolidation in the field can be determined knowing the consolidation parameters. Equations are developed by using output of the programme and it is explained.
ANALYSIS OF RING JET LASER GYRO RESONANT DITHERING MECHANISM P singh
This paper presents the design, manufacture, testing and improvement of newly developed piezoelectric torsion actuator which generates angular displacement using piezo ceramics and torsion bar. The proposed piezoelectric torsion actuator generates angular displacement during dithering, directly invoking the shear mode of the piezoelectric material and hence no complicated additional mechanism is needed. The piezo plates are formed from a rectangular PZT material duly poled along the axial direction. The dither mechanism is divided into four segments that are arranged in circular configuration. Each of the segments off our piezoplates is bonded in opposite poling directions with soldering adhesive. The key to design of such an actuator is to match the torsion resonant frequency of the actuator with the excitation frequency. FEA for the Torsion bar is carried out to find the different resonant mode sand mode shapes. Also, a set of torsion bars and resonator are analyzed to evaluate the maximum angular displacement and stresses on torsion bars. An experimental investigation in terms of electrical impedance and angular displacement measurement was conducted to verify the mode analysis. Based on the FEA analysis, a new material for the torsion actuator was selected having high Curie temperature and stable relative dielectric constant so that it has higher tentivity even after bonding the piezo plates on torsion bars and also wire soldering process. The design analysis was verified with the experimental results for incorporation of the selected mechanism for the production of dither in the system.
CLOUD COMPUTING: SECURITY ISSUES AND CHALLENGESP singh
Cloud storage is defined as "the storage of data online in the cloud," wherein a company's data is stored in and accessible from multiple distributed and connected resources that comprise a cloud. Although cloud service providers implement the best security standards and industry certifications, storing data and important files on external service providers always opens up risks. Using cloud-powered technologies means you need to provide your service provider with access to important business data. Meanwhile, being a public service opens up cloud service providers to security challenges on a routine basis. The ease in procuring and accessing cloud services can also give nefarious users the ability to scan, identify and exploit loopholes and vulnerabilities within a system. For instance, in a multi-tenant cloud architecture where multiple users are hosted on the same server, a hacker might try to break into the data of other users hosted and stored on the same server. The following paper deals with the service models of cloud computing along with types of cloud computing & characteristics of cloud. Further challenges and security issues in cloud computing is also discussed and at last conclusion and future demand for research in the field of cloud computing.
STUDY ON THE BEHAVIOUR OF CUO NANO PARTICLES IN RADIATOR HEAT EXCHANGER FOR A...P singh
In this present study, the forced convective heat transfer performance of automobile radiator has been studied experimentally by using Nano fluid (CuO-Water) as a coolant for an automobile radiator.. Experimental works were conducted to investigate the effect of Copper-Oxide (CuO) nanoparticles volume concentration and the operating temperatures on the rate of Nano fluids heat transfer in a radiator heat Exchanger. CuO nanoparticles were mixed with the base fluid water and also Sodium Lauryl Sulphate (SLS) powder was added to enhance the mixing process and stabilize the dispersion of the Nano fluids. Experimental runs were conducted at varying operating temperatures which include that, CuO-water at different temperature such as 40℃, 50℃, 60℃, 70℃, 75℃, 78℃, 80℃, 83℃. Among the operating temperatures selected for study 80℃, gives the best performance in heat transfer and the convection heat transfer coefficient. The results of the current work generally indicate that Nano fluids have the potential to enhance the heat transfer of a compact heat exchanger. Results indicate that, best overall heat transfer coefficient for the radiator is obtained at a hot fluid inlet temperature of 80℃, and at a flow rate of 0.075kg/sec.
SIGNIFICANCE OF RATIONAL 6TH ORDER DISTORTION MODEL IN THE FIELD OF MOBILE’S ...P singh
The document discusses a proposed method for video watermarking that uses spatial and frequency domain techniques for embedding watermark information, and tests the method's robustness against rational 6th order distortion. The key steps are: (1) extracting frames from a video and selecting the highest entropy frame, (2) using spread spectrum and LSB techniques to embed a watermark in the spatial domain and DWT in the frequency domain, (3) applying rational 6th order distortion to test the effect on the watermarked video, (4) calculating metrics like correlation, SSIM, PSNR, BER and MSE to evaluate the method and detect the watermark from the distorted video. The results show the values of correlation and SSIM
TRANSIENT ANALYSIS ON 3D DROPLET OVER HORIZONTAL SURFACE UNDER SHEAR FLOW WIT...P singh
The document discusses transient analysis of a 3D liquid droplet on a horizontal surface under shear flow using computational fluid dynamics. A finite volume method with volume of fluid modeling is used to simulate the droplet shape change and movement. Six cases are studied including variations in droplet size, contact angle, fluid properties, and inlet air velocity. Results show the droplet dynamics and acquired velocity depend on these boundary conditions and external effects. The study provides insights into controlling droplet movement for applications like micro pumps and coating devices.
STRUCTURAL RELIABILITY ASSESSMENT WITH STOCHASTIC PARAMETERSP singh
The performance of a structure [23] is assessed by its safety [1], serviceability [1] and economy [1]. Since we do not know the exact details of loads [4] acting on a structure at any time, there is always some uncertainty about the total loads on structure. Thus random variables (means stochastic variable) of loads and other parameters are the main criteria of design variables [18]. They vary with space and time. The input variables is never certain and complete. The safety factor provided in the existing codes and standers primarily based on practice, judgment and experience, may not be adequate and economical. Using the techniques presented earlier, we can design or analyze individual members in the contest of structural reliability [2][3][22][24]. However we are not examined how the system performs [23] or how to calculate the reliability of the structure as a whole.
VLSI ARCHITECTURE OF AN 8-BIT MULTIPLIER USING VEDIC MATHEMATICS IN 180NM TEC...P singh
A Multiplier is one of the key hardware blocks in most fast processing system which requires less power dissipation. A conventional multiplier consumes more power. This paper presents a low power 8 bit Vedic Multiplier (VM) based on Vertically & Crosswise method of Vedic mathematics, a general multiplication formulae equally applicable to all cases of multiplication. It is based on generating all partial products and their sum in one step. The implementation is done using cadence Virtuoso tool. The power dissipation of 8x8 bit Vedic multiplier obtained after synthesis is compared with conventional multipliers such as Wallace tree and array multipliers and found that the proposed Vedic multiplier circuit seems to have better performance in terms of power dissipation.
VIBRATION BUCKLING AND FRACTURE ANALYSIS OF CYLINDRICAL SHELLP singh
Shell structures are widely used in civil, mechanical, aerospace and marine engineering applications (e.g. offshore oil tanks, automotive industry, aircraft and submarines). Like other types of structures, they are susceptible to various types of defect and damage such as cracking, corrosion, chemical attack and time-dependent material degradation, which may impair their structural integrity and affect their service life. The presence of cracks in a cylindrical structure can considerably affect its behavior. The effects of these imperfections on load carrying capacity and safety are thus important considerations in the design of cylindrical shell structures. This present work presents a finite element study on the vibration, buckling and fracture behavior of a cracked cylindrical shell with clamped type supports and subject to a time varying rotating speed. Vibration, linear elastic buckling and fracture parameters of a cracked cylindrical shell with time-varying rotating speed are analyzed. The effects of constant rotating speed, crack length and orientation of crack and length-diameter ratio of the cylindrical shell on the free-vibration and buckling behaviors are investigated.
HIGH SCHOOL TIMETABLING USING TABU SEARCH AND PARTIAL FEASIBILITY PRESERVING ...P singh
The high school timetabling is a combinatorial optimization problem. It is proved to be NP-hard and has several hard and soft constraints. A given set of events, class-teacher meetings and resources are assigned to the limited space and time under hard constraints which are strictly followed and soft constraints which are satisfied as far as possible. The feasibility of timetable is determined by hard constraints and the soft constraints determine its quality. Difficult combinatorial optimization problems are frequently solved using Genetic Algorithm (GA). We propose Partial Feasibility Preserving Genetic Algorithm (PFP-GA) combined with tabu search to solve hdtt4, “hard timetabling” problem a test data set in OR-Library. The solution to this problem is zero clashes and maintaining teacher’s workload on each class in given venue. The modified GA procedures are written for intelligent operators and repair. The PFP-GA in association with Tabu Search (TS) converges faster and gives solution within a few seconds. The results are compared to that of using different methodologies on same data set.
Due to its impact on human health and the nature surrounding us, diesel engine emissions have been significantly reduced over the last two decades. This reduction has been enforced by the legislating organs around the world that gradually have made the manufacturers transform their engines to today’s complex high‐tech products. One of the most challenging area to meet the legislations is the emissions of the diesel engine which are the products of the combustion of diesel fuel. More restrictions have been imposed by the some governments to reduce these emissions to a level such that will not cause any harmful impacts for the environment after releasing them to the atmosphere. This paper examines the effects of combusting a mixture of diesel fuel, water, and surfactant which forms emulsion on the nitrogen oxides, or NOx, carbon monoxide CO, carbon dioxide CO2, sulfur oxides SOx emissions and particulate matter (PM) from a compression ignition diesel engine. Previous research has attributed the observed reduction of these emissions to a suppression of flame temperature due to quenching effects from the water, thereby reducing thermal NOx formation and other pollutants. The focus of this review paper will be on experiments were conducted a using diesel engine with pure diesel fuel and emulsion of water-diesel. Furthermore, results from the testing diesel fuel that mixed with varied ratios of water balanced with a surfactant to stabilize the emulsion will be presented and discussed. Three different samples of water- diesel emulsion were used with 10 % water and 90 % diesel, 20 % water and 80% diesel, and 30 % water and 70 % diesel (by volume) respectively to conduct the experiments in the lab . The purpose was to see the impact of adding the water from 10 % up to 30 % (by volume) to the diesel fuel making the emulsion fuel to explain what will occur to the emissions and the performance of the engine. The data shows significant NOx emission reduction when using the emulsion water diesel fuel of 30 % water (by volume) in diesel. These results are correlated with a thermodynamic first law analysis to estimate the adiabatic flame temperature of the standard fuel and fuel-water emulsion cases. Results indicate that thermal NOx is indeed reduced by quenching and flame temperature suppression confirming reports in the literature. Recommendations are given for further studies, including improving the fuel—water emulsion and considerations for long-term testing.
USAGE OF ETHANOL BLENDED PETROL: EXPERIMENTAL INVESTIGATIONS OF REDUCTION IN ...P singh
An experimental study was conducted to evaluate what extent ethanol blends in Petrol helps in reduction of pollution levels of SI engines exhaust emissions. Ethanol blends E5, E10, E15, E20, E22 were tested and found considerable reductions in the pollutant levels of CO, CO2, HC. The results indicate better combustions in petrol engine with ethanol blends. The reductions in HC and CO were to the extent of 80% to 90% compared to pure petrol fuelled IC engine.
DESIGN CALCULATION FOR EQUIPMENT AND COMPONENTS SPECIFICATION OF LUBRICATING ...P singh
The lubricating oil system is primarily used to lubricate wear surfaces to minimize friction losses, it cools internal engine parts which cannot be directly cooled by the engines’ water cooling system and it cleans the engine by flushing away wear particles amongst others. Adequate lubrications require lubricant (oil) with sufficient film strength to withstand bearing pressure and viscosity index low enough to allow adequate flow when subjected to heat. The system consist of the tanks (storage, settling, sump and head), lube-oil pumps, strainers, oil coolers, piping, valves, and fittings, lubricating oil purifier, sub system and condition monitoring devices amongst others. The lubricating oil system for a tug boat whose transmitting power is about 955KW was calculated mathematically to obtain the flow rate of the shaft line bearing cooling oil, stern tube bearing cooling oil, main engine camshaft bearing cooling oil and main engine camshaft bearing cooling oil. Modelled equations were employed to obtain the camshaft lube-oil pump capacity, surface area and storage tank. The cylinder lube-oil storage and density tanks were estimated to be 1m3 while the transfer pump is calculated to be approximately 0.4m3/hr. The various suction and discharge diameters and velocities of pumps in the lubricating oil system were determined; it was observed the suction pipe diameter is always bigger than the discharge pipe diameter while the discharge velocity is higher than the suction velocity for all the pumps including the camshaft lube-oil pump, cylinder oil transfer pump and main lube-oil transfer pump. This is a clear indication that the said design process met the international standard for the design of such a tug boat. Similarly the shaft line bearing cooling oil pipe, piston bearing cooling oil pipe and main engine lube-oil pipe discharge velocities were seen to be at the acceptable limits obeying the classification rules. All designs were done in accordance to the Lloyd’s specification rules and regulations for a sea going tug boat.
A LOW VOLTAGE DYNAMIC SYNCHRONOUS DC-DC BUCK-BOOST CONVERTER FOUR SWITCHES P singh
This paper presents the design and modeling of synchronous DC-DC buck-boost converter four switches controlled with PID controller for mobiles devices applications. The design of the converter circuit needs modeling and simulating its mathematical equations using MATLAB/SIMULINK. The evaluation of the output performance has been based on dynamic respond in term of rise time, settling time and peak time. Also the goal of the designer is regulated the output voltage to 3.24 regardless the variation of the input voltage, with input voltage [2.5V-5V] and switching frequency is 50 MHz. The converter is operated in Buck (step-down) and Boost (step-up) modes.
SAUSAGE MINKOWSKI SQUARE PATCH ANTENNA FOR GPS APPLICATIONP singh
Square Patch Antennas find wide range in practical modern communication system. The novel idea employed in this paper is to use Sausage Minkowski of square patch antenna as a candidate for using in Global Positioning System (GPS) applications. The antenna has been designed to operate at frequency resonance of 1.575 GHz which is the upper GPS band (L1). The proposed antenna is designed and simulated using CST Studio suite version-2014. The proposed antenna has been simulated on substrate TMM4 of relative permittivity equals to 4.5 and thickness of 1.6 mm. The results are reported in terms of reflection coefficient, VSWR, directivity and gain. According to our results, the antenna at 2nd iteration has gain 4.61dB, VSWR is 1.2 and reduce in area of patch about 42.8% less than 0 iteration. The antenna is more efficient by applying fractal geometry.
ACEP Magazine edition 4th launched on 05.06.2024Rahul
This document provides information about the third edition of the magazine "Sthapatya" published by the Association of Civil Engineers (Practicing) Aurangabad. It includes messages from current and past presidents of ACEP, memories and photos from past ACEP events, information on life time achievement awards given by ACEP, and a technical article on concrete maintenance, repairs and strengthening. The document highlights activities of ACEP and provides a technical educational article for members.
International Conference on NLP, Artificial Intelligence, Machine Learning an...gerogepatton
International Conference on NLP, Artificial Intelligence, Machine Learning and Applications (NLAIM 2024) offers a premier global platform for exchanging insights and findings in the theory, methodology, and applications of NLP, Artificial Intelligence, Machine Learning, and their applications. The conference seeks substantial contributions across all key domains of NLP, Artificial Intelligence, Machine Learning, and their practical applications, aiming to foster both theoretical advancements and real-world implementations. With a focus on facilitating collaboration between researchers and practitioners from academia and industry, the conference serves as a nexus for sharing the latest developments in the field.
Low power architecture of logic gates using adiabatic techniquesnooriasukmaningtyas
The growing significance of portable systems to limit power consumption in ultra-large-scale-integration chips of very high density, has recently led to rapid and inventive progresses in low-power design. The most effective technique is adiabatic logic circuit design in energy-efficient hardware. This paper presents two adiabatic approaches for the design of low power circuits, modified positive feedback adiabatic logic (modified PFAL) and the other is direct current diode based positive feedback adiabatic logic (DC-DB PFAL). Logic gates are the preliminary components in any digital circuit design. By improving the performance of basic gates, one can improvise the whole system performance. In this paper proposed circuit design of the low power architecture of OR/NOR, AND/NAND, and XOR/XNOR gates are presented using the said approaches and their results are analyzed for powerdissipation, delay, power-delay-product and rise time and compared with the other adiabatic techniques along with the conventional complementary metal oxide semiconductor (CMOS) designs reported in the literature. It has been found that the designs with DC-DB PFAL technique outperform with the percentage improvement of 65% for NOR gate and 7% for NAND gate and 34% for XNOR gate over the modified PFAL techniques at 10 MHz respectively.
Literature Review Basics and Understanding Reference Management.pptxDr Ramhari Poudyal
Three-day training on academic research focuses on analytical tools at United Technical College, supported by the University Grant Commission, Nepal. 24-26 May 2024
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.