Thermal-hydraulic performance of MEMS-based pin fin heat sink

An experimental study oil heat transfer and pressure drop of de-ionized water over a bank of shrouded staggered micro pin fins 243 mu m long with hydraulic diameter of 99.5 mu m has been performed. Average heat transfer coefficients have been obtained for effective heat fluxes ranging from 3.8 to 167 W/cm(2) and Reynolds numbers from 14 to 112. The results were used to derive the Nusselt numbers, total thermal resistances, and friction factors. It has been found that for Reynolds numbers below similar to 50 long tube correlations overpredicted the experimental Nusselt number, while at higher Reynolds numbers existing correlations predicted the results moderately well. Endwall effects, which diminish at high Reynolds numbers, and a delay in flow separation for compact pin fills were attributed to the obtained trend.