Measurements of steady-state heat dissipation from miniaturized horizontally-based straight rectangular fin arrays

Abstract

Experiments have been conducted to investigate the effects of miniaturizing the base plate dimensions of horizontally-based straight rectangular fin arrays on the steady state heat dissipation performance. The variation of the steady-state heat dissipation rates per unit base area and the average heat dissipation coefficients within a limited fin base excess temperature above the ambient temperature (from 20 to 50 °C) have been studied as integral aluminum alloy fin arrays were miniaturized by changing the ratio of the base width to length from 0.51 to 1.96 for two inter-fin spacing distances of 3 mm and 11 mm. The miniaturization process have been initiated from a square-based array of 49 × 49 mm (maximum base area of 24.51 × 10–4m2) and terminated at a square-based array of 25 × 25 mm (minimum base area of 6.25 × 10–4m2) with rectangular-based arrays of varying intermediate areas in between. Relevant non-dimensional parameters formulated by earlier similarity analyses for large fin arrays with comparable inter-fin-spacing distances and fin heights have been found inadequate for generalizing the results. Modifications to correlations proposed for large fin arrays have been made by including the effect of varying the value of the base width to length ratio parameter to correlate the data for miniaturized fin arrays. Two types of correlations for miniaturized horizontally-based straight rectangular fin arrays, one which used the inter-fin separation distance as the prime geometric parameter, and the other, which employed half the fin length, have been presented, on the basis of the experimental conditions of this investigation.