Thermal performance and entropy generation of single‐layer and double‐layer constructal Y‐shaped bionic microchannel heat sinks

Abstract

A kind of Y-shaped bionic microchannel (YBMC) heat sink is proposed and designed based on bionic concept and constructal law. A discontinuous Galerkin finite element method is applied to solve incompressible steady laminar flow and heat transfer in microchannels, and an optimal design strategy for geometrical parameters of the double-layer microchannels with counterflow arrangement is adopted. Results reveal that the proposed YBMC configuration provides much better thermal performance and lower total pressure drop subject to the same mass flow rate when compared to microchannels with rectangular straight configuration. Yet the YBMC design offers a more uniform temperature distribution along the heated surface. By using the principle of entropy generation, the degree of irreversible loss of the Y-shaped bionic cases is much less than those of the rectangular case. The pressure rises at the bifurcations of the first-stage, and the second-stage is related to the restart of boundary layer, confirming that the YBMC exhibits high thermal performance.