Pseudo 3D topology optimization of microchannel heat sink with an auxiliary objective

This paper investigated the application of pseudo 3D (P3D) variable-density topology optimization to the design of microchannel heat sink (MHS). To mitigate the grey-element issue and improve the precision of P3D model, outside surface viscous dissipation, adaptive equivalent heat transfer coefficient and auxiliary objective was introduced. The effects of adaptive equivalent heat transfer coefficient, auxiliary objective and its corresponding weight factor on the optimal design were analyzed. The results showed that the new proposed topological model can effectively mitigate intermediate density, improved accuracy and produced a well-defined structure. Furthermore, to validate the design of topology optimization, full 3D numerical simulations were adopted to investigate the fluid flow and heat transfer performance of the topological model and the results were compared with the conventional straight MHS. It is found that the increase of average inlet velocity and temperature uniformity of the topological MHS can be up to 305% and 69%, respectively, under the same inlet pressure. While under the same pumping power consumption, the average heat source temperature of the topological microchannel heat sink can be 9.3°C lower than the conventional one.