Numerical Optimization of the Thermal Performance of a Porous-Microchannel Heat Sink

Abstract

The present study deals with the optimal geometric parameters design of a microchannel heat sink (MCHS) filled with sintered porous medium through an optimization procedure. This procedure integrates the simplified conjugate-gradient method (SCGM) and a three-dimensional heat sink model as an optimizer. The optimal design variables such as the number of channel N, channel-width ratio β, and channel aspect ratio α that minimize the overall thermal resistance of the microchannel heat sink are obtained under various pumping powers and porous conditions. Optimization results show that, for a given pumping power, the optimal design variables are N = 108, β = 0.90, and α = 8.15, with a corresponding minimum overall thermal resistance of 0.070 K W−1, and the overall thermal resistance is decreased by 40% over that of the initial guess (N = 56, β = 0.4, α = 4.8, and R T = 0.115 K W−1). The predicted results also reveal that the optimal thermal resistance and all the corresponding optimal values of N, β, and α decrease with the increase of porosity. Moreover, as the pumping power increases, the optimal thermal resistance decreases, both the corresponding optimal values of N and α increase, where as β reaches a maximum limitation. The proposed combined approach is effective in optimizing the geometric parameters for a porous-microchannel heat sink.