Numerical investigation and optimization of a heat sink having hemispherical pin fins

A numerical study was conducted aiming to examine the hydrothermal performance of a heat sink having hemispherical pin fins (HSPFs) under fully turbulent flow conditions and to find the optimum HSPFs configuration. In the first stage, a heat sink having staggered arranged cylindrical pin fins (CPFs) was selected as the reference case, and the numerical procedure followed in the present study was validated. In the second stage, the hydrothermal performance of solid-HSPs was numerically investigated and compared with the performance of the reference case. The highest the hydrothermal performance factor (HTPF) was found as 1.87 for the fin diameter (d) to channel height (H) ratio (d/H = 0.833), and Reynolds number (Re = 21,367). This configuration was selected as the base case, and in the last stage, its hydrothermal performance was augmented through the perforation technique. The effects of six different perforation patterns having a various number of holes on the hydrothermal performance were investigated in detail. The highest HTPF was obtained as 1.98 which is around %5.6 times higher than the base case, for the pattern with the most holes. In addition, with the proposed HSPFs configuration, the volume of the heat sink was reduced up to 76% compared to the reference case.