Experimental Study of Jet Nanofluids Impingement System for Cooling Computer Processing Unit (original) (raw)
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Nanomaterials, 2019
A modern computer generates a great amount of heat while working. In order to secure appropriate working conditions by extracting the heat, a specific mechanism should be used. This research paper presents the effect of nanofluids on the microchannel heat sink performance of computer cooling systems experimentally. CeO2, Al2O3 and ZrO2 nanoparticles suspended in 20% ethylene glycol and 80% distilled water are used as working fluids in the experiment. The concentration of the nanoparticles ranges from 0.5% to 2%, mass flow rate ranges from 0.028 kg/s to 0.084 kg/s, and the ambient temperature ranges from 25 °C to 40 °C. Regarding the thermal component, parameters such as thermophysical properties of the nanofluids and base fluids, central processing unit (CPU) temperature, heat transfer coefficient, pressure drop, and pumping power have been experimentally investigated. The results show that CeO2-EG/DW, at a concentration of 2% and a mass flow rate of 0.084 kg/s, has with 8% a lower temperature than the other nanofluids and with 29% a higher heat transfer coefficient compared with the base fluid. The Al2O3-EG/DW shows the lowest pressure drop and pumping power, while the CeO2-EG/DW and ZrO2-EG/DW show the highest. However, a slight increase of pumping power and pressure drop can be accepted, considering the high improvement that the nanofluid brings in computer cooling performance compared to the base fluid.
The heat released from the flat surface is cooled by the use of jet impingement technique. The heat flux from the isothermally heated flat surface due to two-dimensional turbulent twin oblique confined slot-jet impingement is studied numerically using the ANSYS FLUENT software. Initially the flow and thermal fields for a normal confined slot-jet impingement are investigated using the RNG k-ε model and the SST k-ω model. The local Nusselt number distribution predicted by the SST k-ω model agrees notably better with the existing experimental data. Subsequently, the SST k-ω is employed to study the twin oblique impinging jet heat transfer problem. The study is conducted by varying the jet exit Reynold number, the jet to jet separation distance, jet-exit to target plate distance and the inclination angle of the jet to the impingement. Results indicate that impingement angle is reduced from 90o, the peak Nusselt number at the impingement surface is gradually reduced and its location slightly shifts away from the axis with slight decrease of the average Nusselt number for any combination of Re, L, H. The average Nusselt number is a direct function of the Reynold number and the impingement angle and is inverse function of the jet to target plate separation distance.
International Communications in Heat and Mass Transfer, 2013
For improvement in information technology (IT), removing heat from electrical devices is an important factor, and current activities try to investigate (numerically, experimentally) new methods of thermal load managing. Mini-channel liquid cooling is one of the candidates for this purpose. Nanofluid as an innovative heat-transfer fluid was used in mini-channel heat sink. Modeling analyzed in this study is a mini-channel heat sink with 20 × 20 mm bottom. For this purpose, five nanoparticle volume fractions namely 0.8, 1.6, 2.4, 3.2 and 4% in five inlet velocities for both types of nanoparticle containing TiO 2 and SiC were used. Furthermore, effect of a nanoparticle volume fraction on the convective heat transfer coefficient was investigated in different Reynolds numbers. Modeling results were compared with reference analytical calculations. In addition according to the modeling results, correlated equations were obtained for Nusselt number and friction factor, and its accuracies were acceptable.
Experimental and CFD investigation of commercial PC heat sink performance using water and nanofluids
In this study a commercial heat sink was used for cooling a PC processor. As two liquids were applied (i) water and (ii) copper oxide (II) nanofluids 0.0086 and 0.0225 volume fractions. In the experiments the commercial heat sink was fixed to the CPU. Maximal power dissipated by investigated processor was 115 W. Mass flow rate of the investigated liquids was in the range of 0.009 to 0.05 kg/s and the inlet temperatures was in the range of 300 to 305 K. The experimental results were used for validation of numerical model of the analyzed system. For simulation of the heat transfer the commercial CFD package ANSYS Fluent 13 was employed. The laminar flow regime was considered in a fin array area of the investigated heat sink. The model with a good grid quality was developed and validated. The obtained results prove that for CPU cooling water is good enough.
Performance Analysis of Electronics Cooling using Nanofluids in Microchannel Heat Sink
International Journal of Engineering and Technology, 2016
Performance analysis of thermal enhancement for cooled microchannel heat sink (MCHS) using nanofluidsmathematical formulation was investigated and presented in this paper. Heat transfer capability in terms of thermal conductivity, heat transfer coefficient, thermal resistance, heat flux and required pumping power were evaluated on the effectiveness of copper oxide (CuO), silicon dioxide (SiO 2) and titanium dioxide (TiO 2) with water as a base fluid. The results showed that thermal performance augmented by 12.2% in thermal conductivity at particle volume fraction of 4% to CuO-water nanofluid, 11.8% for SiO 2-water and 10.0% for TiO 2-water. The maximum heat transfer coefficient enhances of 12.4% for CuO, SiO 2 is 8.22% and 7.4% for TiO 2 with the same inlet velocity of 3 m/s. The addition of nanoparticle concentration significantly enhances the heat transfer, but elevates the expenses of higher required pumping power to increase the pressure drop. The maximum enhancement of heat flux in CuOwater was found to be 2575 kW/m 2 , 2501 kW/m 2 for SiO 2-water and 2485 kW/m 2 for TiO 2-water nanofluid at 4% of volume fraction. The pressure drop is increased with the mass flow rate of 1021 kg/m3 for CuO-water at 0.5% of volume fraction and 47925 Pa to 54314 Pa pressure drop at 4% of volume fraction. The CuO-water pumping power was found to be the highest at 4% of volume fraction with 102.3 W at 3 m/s inlet velocity compared to SiO 2 and TiO 2 also increased the pumping power of 75.0 W to 90.6 W with increasing volume fraction and pressure drop. The positive thermal results implied that CuOnanofluid is a potential candidate for future applications in MCHS.Further analysis is recommended to be done with various Reynolds number, pumping power and flow rate of nanoparticles to obtain better heat transfer performance of cooling fluids.
International Journal of Advance Research, Ideas and Innovations in Technology, 2019
Due to the reduction in the size of the electronic components, heat dissipation has become a major problem. In many cases, air cooling has failed to provide the required demands. The invention of nanofluid has promised to increase the efficiency of the liquid cooling system. The addition of solid nanoparticles to the liquid actually increases the thermal conductivity of the liquid because of the higher thermal conductivity of the solid particles. In this work, the thermal performance of a minichannel heat sink was analyzed using CFD for cooling of processor chipset using nanofluids instead of pure water. The effect of different mass flow rates and various volume concentrations of nanoparticles on the overall thermal performance are also analyzed. The Alumina and graphene water nanofluids are used as coolants with volume concentrations of 0.1, 0.15 and 0.2%. The cooling fluid is made to flow through an Aluminium mini channel with height 5mm and width 1mm respectively. The maximum allowable temperature that has to be maintained at the chip is below 50oC. By using the liquid cooling system with a heat sink, this temperature is reduced as low as 41.22oC. There is also an enhancement of the convective heat transfer coefficient in using graphene nanofluids when compared to alumina nanofluids. The thermal resistance of the heat sink with nanofluids is lesser than pure water.
Micromachines
Nanofluids offer great potential heat transfer enhancement and provide better thermophysical properties than conventional heat transfer fluids. Application of nanofluids in jet impingement cooling is used for many industrial and scientific purposes as it manages to effectively remove high localized heat. Owing to its tremendous improvement of the heat transfer field, the use of nanofluids in jet impingement cooling has caught the attention of many researchers. This paper reviews previous research and recent advancements of nanofluid jet impingement via both experimental and numerical studies. In experimental approaches, Al2O3-water nanofluids are the most used working fluids by researchers, and most experiments were conducted with conventional impinging jets. As for the numerical approach, the single-phase model was the preferred model over the two-phase model in obtaining numerical solutions, due to the lower computational time required. A deep insight is provided into nanofluid pr...
Heat transfer of nanofluids in the mini-rectangular fin heat sinks
International Communications in Heat and Mass Transfer, 2013
In the present study, the heat transfer characteristics of nanofluids cooling in the mini-rectangular fin heat sink are studied. The heat sinks with three different channel heights are fabricated from the aluminum by the wire electrical discharge machine with the length, width and base thickness of 110, 60, and 2 mm, respectively. The nanofluids are the mixture of de-ionized water and nanoscale TiO 2 particles. The results obtained from the nanofluids cooling in mini-rectangular fin heat sink are compared with those from the de-ionized water cooling method. Effects of the inlet temperature of nanofluids, nanofluid Reynolds number, and heat flux on the heat transfer characteristics of mini-rectangular fin heat sink are considered. It is found that average heat transfer rates for nanofluids as coolant are higher than those for the de-ionized water as coolant. The results of this study are of technological importance for the efficient design of cooling systems of electronic devices to enhance cooling performance.
CFD Analysis of Liquid-Cooled Heatsink Using Nanofluids in Computer Processors
Scientia Iranica
In this study, a computer model of the Zalman ZM-WB3 Gold heat exchanger which is one of the liquid-cooled computer processors in the market has been generated and the model has been confirmed by the previous researchers' models and experimental data. Then, the fin thickness and heights of the same heat exchanger and the type of liquid fluid in which the heat exchanger operates have been changed. The CFD analyzes of the new models were performed by using Ansys Fluent 17.1 program. Following that, nano heat removal (cooling) performances were investigated with models using rectangular fin fluid heat exchangers with different fin heights of 5 mm, 5.5 mm and 5.7 mm, and different fin thicknesses of 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm and 2 mm, and different fluids as water, copper oxide-water (CuO-H 2 O) nanofluids with volume ratios of 2.25% and 0.86%, and graphene oxide (GO-H 2 O) nanofluid with the volume ratio of 0.01%. It was concluded that the best CPU cooler performance could be achieved by using CuO-H 2 O as nanofluid with a volumetric ratio of 2.25% with a heat exchanger that has a 5.5 mm fin height and 2.0 mm fin thickness.
Nanofluid impingement jet heat transfer
Nanoscale Research Letters, 2012
Experimental investigation to study the heat transfer between a vertical round alumina-water nanofluid jet and a horizontal circular round surface is carried out. Different jet flow rates, jet nozzle diameters, various circular disk diameters and three nanoparticles concentrations (0, 6.6 and 10%, respectively) are used. The experimental results indicate that using nanofluid as a heat transfer carrier can enhance the heat transfer process. For the same Reynolds number, the experimental data show an increase in the Nusselt numbers as the nanoparticle concentration increases. Size of heating disk diameters shows reverse effect on heat transfer. It is also found that presenting the data in terms of Reynolds number at impingement jet diameter can take into account on both effects of jet heights and nozzle diameter. Presenting the data in terms of Peclet numbers, at fixed impingement nozzle diameter, makes the data less sensitive to the percentage change of the nanoparticle concentrations. Finally, general heat transfer correlation is obtained verses Peclet numbers using nanoparticle concentrations and the nozzle diameter ratio as parameters.