Heat transfer of nanofluids in the mini-rectangular fin heat sinks (original) (raw)
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The thermal management of electronic devices has become a major problem in recent years. Therefore, there is a growing need for research on many new materials and innovative fluids due to the developing technology and increasing cooling need in electronic systems. In this paper, heat transfer from a plate fin and pin fin type heat sinks that were placed in a water block that are used in electronic systems was investigated. A base fluid (pure water) and 0.1% mass concentration Al2O3-H2O nanofluid were used as cooling fluids. The experiments were carried out for volumetric flow rates varying between 100 and 800 mL/min and heat flux values of 454.54 W/m2 and 1818.18 W/m2. The results demonstrated that the Al2O3-H2O nanofluid on the empty surface provided a maximum improvement of 10.5% in heat transfer compared to the base fluid. In the use of plate finned heat sink, the maximum amount of improvement in heat transfer compared to the empty surface was obtained approximately 64.25% for th...
In this paper, the hydrodynamic and thermal performance of a miniature plate pin finned heat sink is investigated experimentally by utilizing two widely used nanofluids, Al2O3-water and TiO2-water. The heat sink base plate which is used in the cooling process of electronic devices, has the dimensions of 42 mm (L)×42 mm (W)×14 mm (H) and is made of Aluminum and placed in a plexiglass case which is isolated from the environment using an insulator foam. The thermal performance of the heat sink is investigated by passing the nanofluid at constant inlet temperature while applying a constant heat flux of 124.8 kW/m2 to the bottom surface of the heat sink. The nanofluids are prepared in volume concentrations of 0.5, 1, 1.5, and 2 percent and their performances are measured considering water as the base fluid. Measuring the pressure difference between the entrance and exit of the heat sink made it possible to study the hydrodynamic performance of the heat sink. Although the measurements showed 15% and 30% increase in the pumping power for the volume concentration of 2 % of Al2O3-water and TiO2-water nanofluids, respectively, the average heat transfer coefficients increased by 16% and 14% and the thermal resistance decreased by 17% and 14% for each nanofluid.
Investigation of flow and heat transfer characteristics in micro pin fin heat sink with nanofluid
I studied the effect of using nanofluid in micro pin fin heat sink. Two nanofluids have been studied (diamond-water and Al 2 O 3-water). Three fins shapes (square, triangular and circular) and unfinned heat sink. Results show that nanofluid increase the thermal performance and pressure drop. The circular fins give higher heat transfer rate compared with other fins. a b s t r a c t In this paper a micro pin fin heat sink is numerically investigated with three fins geometries (square, triangular and circular) in addition to the unfinned microchannel heat sink. Nanofluid is used as a cooling fluid, since the flow and heat transfer have been studied with two types of nanofluids (Diamond-water and Al 2 O3-water) in addition to the pure water. The volumetric concentration of selected nanofluids has been chosen in range (1e4)%. The comparison of hydrodynamic and thermal characteristics of different fin geometries and cooling fluids has been made under the same value of Reynolds number and constant wall temperature thermal boundary condition, the range of Re used is (100e900) to ensure that, the flow remains in the laminar regime. The results obtained indicated that, using of nanofluid instead of pure fluid as a coolant leads to enhanced heat transfer performance by increasing the amount of heat dissipated but it also leads to increased pressure drop for all fins shapes and nanofluids studied.
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 Thermal and Fluid Science, 2015
This study presents the experimental thermal and hydraulic performance of heat sink with miniature circular pin fin structure using two different types of nanofluid as coolant. ZnO and SiO 2 nanoparticles dispersed in DI water with particle volume fraction of 0.2, 0.4 and 0.6 vol.% are tested and compared with the data for water. A heat sink with inline arrangement of circular pins is designed and made from aluminum material. The height, diameter, pitch, and number of pins are 1.2, 1.2, 2.4 mm and 143, respectively. Uniform heat flux at the bottom of the heat sink is performed. The present work is conducted at fluid temperature of 15°C. The mass flow rate ranged from 0.65 to 3.32 kg/min and the heat flux ranged between 20 and 48 kW/m 2. The effects of particle type, particle concentration, and mass flow rate on the thermal and hydraulic performances are reported. The measured data show that the heat transfer performance of the nanofluid-cooled heat sink is higher than that of the water-cooled heat sink. Comparison between ZnO and SiO 2 nanofluids, higher heat transfer performance for ZnO-water nanofluids is observed by about 3-9%. For hydraulic performance, the results show that the addition of nanoparticles in the base fluid have a small effect on the pumping power. Finally, new heat transfer and pressure drop correlations are proposed to predict the Nusselt number and pressure drop of nanofluids flow in heat sinks with pin fin configuration.
Experimental Evaluation of Nanofluid for Improved Cooling Efficiency in an AL Mini Channel Heat Sink
International Journal for Research in Applied Science & Engineering Technology (IJRASET), 2022
Efficient heat transfer has become major need these days. In this thesis, both experimental and CFD investigations have to be carried out to evaluate the cooling performance of a mini-channel consisting of fins on upper surface of flat plate. Nano fluids contain a small fraction of solid nano particles in base fluids flowing through groves in bottom plate attached with heater at base. Nano fluids cools small channel heat sinks, have been anticipated to be an excellent heat dissipation method for the next generation electronic devices. Computational Fluid Dynamics (CFD) simulations is to be carried out to study the heat sinks heat transfer mechanism. The sectional geometry of channels affects the flow and heat transfer characteristics of mini channel heat sinks. The heat transfer principle states that maximum heat transfer is achieved in mini channels with minimum pressure drop across it. In this research work the experimental and numerical investigation for the improved heat transfer characteristics of mini channel heat sink using Al2O3/water nano with (1 and 2 % volume fraction) fluid is to be done. The fluid flow characteristics are also analysed for the serpentine shaped mini channel. Heating element of 130 W capacities is to be used to heat up the heating element of base plate.
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.
Heat transfer with nanofluids for electronic cooling
International Journal of Materials and Product Technology, 2009
In response to the ever increasing demand for smaller and lighter high performance cooling devices a new heat transfer liquids come into picture, called Nanofluids. Nanofluids are new class of heat transfer fluids developed by suspending nanosized solid particles in liquids. Larger thermal conductivity of solid particles compared to the base fluid such as water, ethylene glycol, engine oil, etc. significantly enhances its thermal properties. Numbers of phenomenological models have been proposed to explain the anomalous heat transfer enhancement in nanofluids. This paper presents systematic literature survey observed to exploit several characteristic behaviours of nanofluids viz. increase in thermal conductivity, specific heat and other thermal properties. An empirical correlation for Al 2 O 3 + water nanofluid and effects of temperature, volume fraction and size of nanoparticle is studied. The effect of temperature on nanofluid thermal conductivity is also brought out. This behaviour combined with better mechanical properties makes fluids embedded with nanomaterials are excellent candidates for future applications.
Study of heat transfer enhancement in a nanofluid-cooled miniature heat sink
International Communications in Heat and Mass Transfer, 2012
This paper reports numerical solution for thermally developing temperature profile and analytical solution for fully developed velocity profile in a miniature plate fin heat sink with SiO 2-water nanofluid as coolant. The flow regime is laminar and Reynolds number varies between 0 and 800. The heat sink is modeled using porous medium approach. Modified Darcy equation for fluid flow and the two-equation model for heat transfer between the solid and fluid phases are employed to predict the local heat transfer coefficient in heat sink. Results show that the nanofluid-cooled heat sink outperforms the water-cooled one, having a considerable higher heat transfer coefficient. The effects of channel aspect ratio and porosity on heat transfer coefficient of the heat sink are studied in detail. Based on the results of our analysis, it is found that an increase in the aspect ratio or the porosity of the plate fin heat sink enhances the heat transfer coefficient.
Journal of Thermal Science and Engineering Applications, 2015
In this paper thermal and hydrodynamic performances of a miniature tangential heat sink are investigated experimentally by using Al 2 O 3 -H 2 O and Tio 2 -H 2 O nanofluids. The effects of flow rate and volume concentration on the thermal performance have been investigated for the Reynolds number range of 210 to 1100. Experimental results show that the average convective heat transfer coefficient increases 14 % and 11% and the bottom temperature of the heat sink decreases 2.2˚C and 1.6˚C by using Al 2 O 3 -H 2 O and Tio2-H 2 O nanofluid instead of pure distilled water, respectively.