Development of Prediction Technique for Cooling Performance of a Heatsink with Plate Fins.

Abstract

Numerical calculation was carried out on flow and temperature fields around a heatsink with plate fins subjected to a uniform flow, varying the ratio of fin length L to the half-pitch of fins s. The average flow velocity between fins Uf became lower, as Re0 s/L decreased, where Re0 was Reynolds number defined by uniform flow velocity and s. It was also found that friction resistance and heat transfer of the fins showed excellent agreement with those of parallel plates with uniform inlet flow velocity equal to Uf. A prediction technique for the cooling performance of the heatsink was developed in which Uf was estimated under the condition of constant pressure distribution at its downwind edge. The present technique can predict the heat transfer of the fins with error level below 30% under practical conditions of electronics design, while it underestimates Uf in the region of small Re0 s/L.