The Experts below are selected from a list of 4650 Experts worldwide ranked by ideXlab platform
Madhusree Kole - One of the best experts on this subject based on the ideXlab platform.
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thermal performance of Screen Mesh wick heat pipes using water based copper nanofluids
Applied Thermal Engineering, 2013Co-Authors: Madhusree KoleAbstract:Abstract Fairly stable surfactant free copper–distilled water nanofluids are prepared using prolonged sonication and homogenization. Thermal conductivity of the prepared nanofluid displays a maximum enhancement of ∼15% for 0.5 wt% of Cu loading in distilled water at 30 °C. The wall temperature distributions and the thermal resistances between the evaporator and the condenser sections of a commercial Screen Mesh wick heat pipe containing nanofluids are investigated for three different angular position of the heat pipe. The results are compared with those for the same heat pipe with water as the working fluid. The wall temperatures of the heat pipes decrease along the test section from the evaporator section to the condenser section and increase with input power. The average evaporator wall temperatures of the heat pipe with nanofluids are much lower than those of the heat pipe with distilled water. The thermal resistance of the heat pipe using both distilled water and nanofluids is high at low heat loads and reduces rapidly to a minimum value as the applied heat load is increased. The thermal resistance of the vertically mounted heat pipe with 0.5 wt% of Cu–distilled water nanofluid is reduced by ∼27%. The observed enhanced thermal performance is explained in light of the deposited Cu layer on the Screen Mesh wick in the evaporator section of the heat pipe.
Ridho Irwansyah - One of the best experts on this subject based on the ideXlab platform.
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Pool Boiling of Nanofluids in Vertical Porous Media
Applied Mechanics and Materials, 2013Co-Authors: Ridho Irwansyah, Nandy PutraAbstract:The development of electronic components such as microprocessor requires a better thermal management system to overcome the high heat flux produce by the component. The method to absorb the heat produce by the microprocessor is still use the conduction or either natural or free convection which still in a single phase heat transfer. One of heat transfer method that suitable for a high heat flux application is pool boiling which has a two order of magnitude higher than of a single phase heat transfer and does not require a pump to move the fluid. In this study has been conducted the pool boiling experiment with four different porous media surface which are sintered copper 300 µm and 400 µm, copper Screen Mesh and stainless steel Screen Mesh with four different fluid which are Al2O3-Water 1%, 3% and 5%. The sintered copper 400 µm has shown a better heat transfer performance compared to the other porous media. The Water, Al2O3-Water 5% has shown a performance no better than Al2O3-Water 1% and 3%.
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thermal performance of Screen Mesh wick heat pipes with nanofluids
Experimental Thermal and Fluid Science, 2012Co-Authors: Nandy Putra, Haolia Rahman, Wayan Nata Septiadi, Ridho IrwansyahAbstract:Heat pipes have been widely used as one of the alternative methods to absorb more heat in the cooling systems of electronic devices. To improve the thermal performance of heat pipes, the practice of using various combinations of heat pipes and nanofluids has been widely observed. The purpose of this research was to determine the concentrations and the types of nanofluids that can best enhance the thermal performance of Screen Mesh wick heat pipes and to determine the effect of coatings on the structure of the Screen Mesh wick after using nanofluids as the working fluid. In this research, Screen Mesh wick heat pipes were manufactured and tested to determine the thermal resistance of nanofluids such as Al2O3–water, Al2O3–ethylene glycol, TiO2–water, TiO2–ethylene glycol and ZnO–ethylene glycol charged in the Screen Mesh wick heat pipes. The concentration of the nanoparticles was varied from 1% to 5% of the volume of the base fluid. The Screen Mesh wick heat pipe with the best performance was that which used Al2O3–water nanofluid with 5% volume concentration. Using nanofluids in the heat pipes resulted in the formation of a thin coating on the Screen Mesh surface from the element of the nanoparticles. However, the thin coating promotes good capillary structure. The higher thermal performance of heat pipes charged with nanofluids proved the potential of nanofluids as a substitute for conventional working fluids. This finding makes nanofluids attractive as working fluids in Screen Mesh wick heat pipes.
Nandy Putra - One of the best experts on this subject based on the ideXlab platform.
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characteristics of Screen Mesh wick heat pipe with nano fluid as passive cooling system
Atom Indonesia, 2013Co-Authors: Wayan Nata Septiadi, Nandy Putra, Mulya Juarsa, I P A Putra, Ranggi SahmuraAbstract:The heat pipe is one of the cooling media which is potential to be developed for the passive cooling system for nuclear reactors. To enhance the performance of the heat pipe, nanofluids have been used as the working fluid for the heat pipe. This paper studies the characteristics of nanofluids as the working fluid of heat pipe with Screen Mesh wick, which was the mixture of nano-sized particles (Al 2 O 3 and TiO 2 ) with water as the base fluid. The nanoparticles have average diameter of 20 nm, made with 1% to 5% volume fraction. The heat pipe thermal performance was tested using heater with different heat load. The experimental result shows the use of 5% Al 2 O 3 -water improve the thermal performance by reducing the temperature at evaporator side as much as 23.7% and the use of TiO 2 -water reduce the temperature at evaporator side as much as 20.2% compared to the use of water. The use of nanofluid also decreases the thermal resistance of heat pipe. As the use of nanofluid improves thermal performance of heat pipe, it has a potential for applications along with heat pipes at nuclear reactors. Received: 04 December 2012, Revised: 13 February 2013, Accepted: 25 February 2013
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Pool Boiling of Nanofluids in Vertical Porous Media
Applied Mechanics and Materials, 2013Co-Authors: Ridho Irwansyah, Nandy PutraAbstract:The development of electronic components such as microprocessor requires a better thermal management system to overcome the high heat flux produce by the component. The method to absorb the heat produce by the microprocessor is still use the conduction or either natural or free convection which still in a single phase heat transfer. One of heat transfer method that suitable for a high heat flux application is pool boiling which has a two order of magnitude higher than of a single phase heat transfer and does not require a pump to move the fluid. In this study has been conducted the pool boiling experiment with four different porous media surface which are sintered copper 300 µm and 400 µm, copper Screen Mesh and stainless steel Screen Mesh with four different fluid which are Al2O3-Water 1%, 3% and 5%. The sintered copper 400 µm has shown a better heat transfer performance compared to the other porous media. The Water, Al2O3-Water 5% has shown a performance no better than Al2O3-Water 1% and 3%.
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thermal performance of Screen Mesh wick heat pipes with nanofluids
Experimental Thermal and Fluid Science, 2012Co-Authors: Nandy Putra, Haolia Rahman, Wayan Nata Septiadi, Ridho IrwansyahAbstract:Heat pipes have been widely used as one of the alternative methods to absorb more heat in the cooling systems of electronic devices. To improve the thermal performance of heat pipes, the practice of using various combinations of heat pipes and nanofluids has been widely observed. The purpose of this research was to determine the concentrations and the types of nanofluids that can best enhance the thermal performance of Screen Mesh wick heat pipes and to determine the effect of coatings on the structure of the Screen Mesh wick after using nanofluids as the working fluid. In this research, Screen Mesh wick heat pipes were manufactured and tested to determine the thermal resistance of nanofluids such as Al2O3–water, Al2O3–ethylene glycol, TiO2–water, TiO2–ethylene glycol and ZnO–ethylene glycol charged in the Screen Mesh wick heat pipes. The concentration of the nanoparticles was varied from 1% to 5% of the volume of the base fluid. The Screen Mesh wick heat pipe with the best performance was that which used Al2O3–water nanofluid with 5% volume concentration. Using nanofluids in the heat pipes resulted in the formation of a thin coating on the Screen Mesh surface from the element of the nanoparticles. However, the thin coating promotes good capillary structure. The higher thermal performance of heat pipes charged with nanofluids proved the potential of nanofluids as a substitute for conventional working fluids. This finding makes nanofluids attractive as working fluids in Screen Mesh wick heat pipes.
Somchai Wongwises - One of the best experts on this subject based on the ideXlab platform.
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comparative study of the effect of hybrid nanoparticle on the thermal performance of cylindrical Screen Mesh heat pipe
International Communications in Heat and Mass Transfer, 2016Co-Authors: Rajendran Ramachandran, K Ganesan, M R Rajkumar, Lazarus Godson Asirvatham, Somchai WongwisesAbstract:Abstract The thermal performance of a cylindrical Screen Mesh heat pipe with hybrid nanofluid was experimentally investigated. The hybrid nanofluid was prepared by mixing Al2O3 and CuO nanoparticles with deionised water. The heat pipe was fabricated with straight copper tube of dimensions 300 mm length, 12.5 mm outer diameter and 1 mm thickness. The wick structure in the heat pipe was created by a three layer copper Screen Mesh of 100 Mesh size. The heat input to the heat pipe was varied from 50 W to 250 W in five equal steps. The heat pipe was tested with three hybrid nanofluids made with combinations of Al2O3 and CuO nanoparticle in DI water (Al2O3 75%–CuO 25%, Al2O3 50%–CuO 50% and Al2O3 25%–CuO 75%). The tested hybrid nanofluids were made with 0.1% volume concentration of Al2O3 and CuO nanoparticle combination in deionised water. The results of the investigation showed that for the maximum heat load of 250 W considered in this work, the thermal resistance of the hybrid nanofluid with combination, Al2O3 25%–CuO 75%, showed 44.25% reduction compared to deionised water. The reduction in thermal resistance is due to the formation of porous coating on the wick surface which increases the wettability and surface roughness thereby creating more nucleation sites as seen in the SEM images. From the experimental investigation, it was observed that hybrid nanofluids are alternative to the conventional working fluids in heat pipes for electronic cooling applications.
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heat transfer performance of Screen Mesh wick heat pipes using silver water nanofluid
International Journal of Heat and Mass Transfer, 2013Co-Authors: Lazarus Godson Asirvatham, Rajesh Nimmagadda, Somchai WongwisesAbstract:Abstract This study presents the improvement in heat transfer performance of a heat pipe using silver nanoparticles dispersed in DI (De-Ionized) water. The nanoparticles suspended in conventional fluids have superior heat transfer capability due to improved thermal conductivity. The heat pipes are tested for heat inputs ranging from 20 W to 100 W in five steps, which is suitable for removing heat from power transistors in electronics and processors in computers. The effect of various operational limits and test parameters such as heat inputs, volume fraction, vapour temperature on the thermal resistance, evaporation and condensation heat transfer coefficients, are experimentally investigated. The tested silver nanoparticles volume concentration ranged from 0.003% to 0.009% with average nanoparticle diameter of 58.35 nm. The experimental results are evaluated in terms of performance metrics by direct measurement of vapour temperatures in the centre core of heat pipe. A substantial reduction in thermal resistance of 76.2% is observed for 0.009 vol.% concentration of silver nanoparticles. Further an enhancement in the evaporation heat transfer coefficient of 52.7% is observed for the same concentration. The use of nanoparticles enhances the operating range of heat pipe by 21% compared with that of DI water.
C Y Ching - One of the best experts on this subject based on the ideXlab platform.
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characterization of evaporator and condenser thermal resistances of a Screen Mesh wicked heat pipe
International Journal of Heat and Mass Transfer, 2008Co-Authors: Roger Kempers, A J Robinson, D Ewing, C Y ChingAbstract:Abstract The heat transfer mechanisms in the condenser and evaporator sections of a copper-water wicked heat pipe with 3 layers of Screen Mesh were investigated experimentally. The individual condenser and evaporator thermal resistances were measured using thermocouples on the outer wall and within the core of the heat pipe. The heat transfer in the condenser section was found to be only by conduction. In the evaporator, however, either conduction or boiling heat transfer can occur. The transition between the two modes was found to be dependent on the vapor pressure and heat flux, and was reasonably well predicted by the bubble nucleation criterion outlined by Van Stralen and Cole [S. Van Stralen, R. Cole, Boiling Phenomena, vol. 1, McGraw-Hill Inc., 1979]. The experimental data for the boiling heat transfer in the evaporator was well correlated by [St][Pr]0.6[Np]0.2 = 0.13[Re]−1.43. A composite heat transfer model for the heat pipe is proposed that considers both conduction and boiling heat transfer in the evaporator.
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effect of number of Mesh layers and fluid loading on the performance of Screen Mesh wicked heat pipes
Applied Thermal Engineering, 2006Co-Authors: Roger Kempers, D Ewing, C Y ChingAbstract:Abstract An experimental study has been performed to determine the effect of the number of Mesh layers and amount of working fluid on the heat transfer performance of copper–water heat pipes with Screen Mesh wicks. It was found that the effective thermal resistance decreases with an increase in heat flux, and approaches an approximately constant value at higher heat fluxes. This non-linearity in the thermal resistance is larger for wicks with fewer Mesh layers. There is a small increase in thermal resistance of the heat pipe when the thickness of the wick is increased, but this is significantly smaller than that predicted by models based on conduction heat transfer across the wick. For all orientations, the maximum heat transfer through the heat pipe increased as the number of Mesh layers of the wick was increased, as expected. The heat pipes with amounts of working fluid close to that required to fully saturate the wick performed similarly. Heat pipes with significantly less working fluid had somewhat lower effective thermal resistances, but the maximum heat transfer rate was significantly reduced.