Optimization of geometry and flow rate distribution for double-layer microchannel heat sink

•A optimization procedure was developed to optimize double-layer MCHS design.•Pumping power, flow rate, and pressure drop were constraint conditions, respectively.•Five geometric parameters and one flow velocity as search variables were optimized.•Dependences of optimal search variables on constraint conditions were discussed.•The results provide a guide for double-layer MCHS design.

A three-dimensional solid–fluid conjugated model is coupled with a simplified conjugate-gradient method to optimize the flow and heat transfer in a water-cooled, silicon-based double-layer microchannel heat sink (MCHS). Six design variables: channel number, bottom channel height, vertical rib width, thicknesses of two horizontal ribs, and coolant velocity in the bottom channel are optimized simultaneously to search for a minimum of global thermal resistance. The optimal design variables are obtained at fixed pumping powers, coolant volumetric flow rates, and pressure drops through the MCHS, respectively. The dependences of design variables on the increased pumping power, volumetric flow rate, and pressure drop are discussed. Although the combined optimization is proven effective only for the double-layer MCHS with a specific dimension, it is expected that the proposed design strategy provide a valuable guide for the practical double-layer MCHS design.