Özet:

Heat rejection from electronic components by heat sink is still a viable cooling solution. The optimal heat sink design enables higher heat transfer performance. The purpose of the present study is to predict the effectiveness of heat sink elliptical closely spaced fins subjected to impinging air cooling. The air fan is the main source of impinging air, then its position and direction with the heat sink take the main role in present work. Two positions of fan location are studied. The first position where the fan is outside the heat sink and the second case where the fan is existed in a cut out template. So there are one impinging air inlet with four transverse outlets and one axial exit opposite to the air flow inlet. Reynolds number were taken at a range 3400-16000, the flow was turbulent so k-ϵ model turbulence model was used as our choice to simulate mean flow characteristics for turbulent flow conditions. The heat sink base was subjected to constant heat flux condition and proposed with range between 10000–40000 kW/m2 to keep the base temperature at a temperature around 100 oC. The Results of temperature contour lines depicted a variation from the base to the extended surfaces tips. The comparison between the two cases results showed high temperature difference in the case with the cut out template. Nusselts numbers indicated that the second case performed better in heat transfer than the first case. The experimental and numerical results showed a good agreement with a difference not exceeding 2%.

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