Computational Study of Bio-Inspired Pin Geometries for Improved Thermal Performance

Traditional pin fin channel convection cooling methods feature circular cross-section pins. A circular cross-section promotes heat transfer at the cost of increased pressure losses. Investigation into alternative pin fin shapes that are able to reduce the pressure losses without aggressively impacting the heat transfer properties is relevant in applications such as gas turbine engine blade cooling. Eight different pin shapes and two additional redesigned ones are considered in this computational study for their aerothermal performance. A circular and an elliptical pin are used for comparison against bio-inspired pin geometries based on harbor seal whiskers. The seal whisker geometry consists of streamwise and spanwise undulations along the length of the whisker, which are known to reduce the size of the wake and coherent structures shed from the body. The pin fin channel is simulated with a height of 30 mm and eight rows of staggered pin fins. The computational analysis is carried out using an unsteady [Formula: see text] Shear Stress Transport (SST) Reynolds-averaged Navier–Stokes modeling approach and focusing on a Reynolds number of 30,000. This study shows that the bio-inspired pin geometries have an overall 10–39% improvement in thermal performance measured by the efficiency index, which determines the efficiency of the augmented design with respect to the baseline case, in comparison to a circular pin. For comparison to an elliptical pin, about 1–8% improvement in efficiency index is observed. Improvement in thermal performance will lead to reduced penalties associated with cooling flows, which directly translates to improved efficiencies in the system.