Fluid flow and heat transfer in microchannel with porous bio-inspired roughness

Abstract

A numerical simulation is conducted to investigate the hydrothermal performance of microchannel modified with bio-inspired fish scale type roughness structures on the hot bottom surface. The fish scale geometry and permeability of it are varied along with fluid velocity to analyze the effect of these parameters on the heat transfer, pressure drop, and overall performance of the microchannel. The present result indicates that the modified bio-inspired microchannel can enhance significant heat transfer rate than a plain microchannel. It is observed that fish scale geometry, permeability, and Reynolds number has a substantial effect on the hydrothermal performance and the maximum heat transfer can be achieved by solid fish scale type roughness with a considerable pressure drop. However, the pressure drop can be reduced through porous fish scale with a minimal reduction in heat transfer. A maximum heat transfer enhancement of 78.8% and 78.1% is observed for the solid and porous fish scale of Darcy number 10−5, respectively. Besides, a maximum enhancement in friction factor of 48.5% and 37.8% is observed for the solid and porous fish scale of Darcy number 10−5, respectively. Thus, the trade-off between heat transfer and pressure drop is found best in porous fish scale than a solid fish scale microchannel considered in the present study. The maximum overall performance value for every considered case in this study is found as 1.60 for porous fish scales, and 1.56 for the solid fish scale microchannel.