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.

Numerical analysis on the thermal performance of microchannel heat sinks with Al2O3 nanofluid and various fins

“…They disrupt the growth of wall boundary layers, creating high local heat transfer regions at the rib and cavity leading edges [1]. Channel bifurcations [5] likewise create new boundary layer leading edges with high local heat transfer characteristics. This may explain the better thermal performance in fractal microchannels at increasing channel height to width aspect ratio [6].…”

Bubble breakup and boiling heat transfer in Y‐shaped bifurcating microchannels

“…Recently, the Y-shaped bionic microchannel (YBMC) heat sink has received considerable attention owing to its excellent heat transfer performance, where the larger heat transfer coefficient, more uniform temperature distribution, and relatively low pressure drop can be achieved. 41,42 Moreover, recognized as the extremely essential feature of bifurcating microchannels, the understanding on the influence of bifurcating angle on the bubble breakup and flow structures is still insufficient.…”

“…Recently, the Y‐shaped bionic microchannel (YBMC) heat sink has received considerable attention owing to its excellent heat transfer performance, where the larger heat transfer coefficient, more uniform temperature distribution, and relatively low pressure drop can be achieved 41,42 . One of the most key scientific problems for the phase change Y‐shaped bionic microchannel heat sink is the bubble dynamics in heated Y‐shaped microchannels.…”