Heat Transfer Enhancement for Direct-on-Chip Impingement Jet Cooling using Variable Micro Pin Fins and Tapered Impingement Cavity

Although jet impingement cooling with microscale pin fins array demonstrates excellent heat transfer capabilities, it requires optimization by a trade-off between maximizing heat transfer and minimizing pressure drop. The present study focusses on minimizing pressure drop and improving surface temperature uniformity by considering fins with variable height and tapered impingement cavity over the traditional setup with uniform fins and impingement cavity. Numerical investigations are conducted to highlight the underlying mechanism that reduces the pressure drop for non-uniform fins and tapered cavity. Among the different cases investigated, the non-uniform fins with tapered cavity are able to combine the benefits of both - low pressure drop like in the case of bare flat surface and low thermal resistance like in the case of uniform fins. The best performing case has a decreased pressure drop of nearly 40% and it still manages to achieve a reduction of 45.4% in thermal resistance along with better surface temperature uniformity. The analysis thoroughly compares all configurations to conclude non-uniform fins considerably outperforms in heat transfer and temperature uniformity.