Numerical investigation of laminar flow heat transfer characteristics and entropy generation in microchannel with shark-skin bionic structure

In this study, a new modified microchannel heat sink (MCHS) with main riblet and side riblet is designed based on the bionic structure of shark skin. Simulations are carried out under inlet conditions of Re = 100–500, and the effects of side riblet height and the width of the valley between main riblet and side riblet on the heat transfer performance of the microchannel are discussed. The results show that the thermal performance parameter (TP) in this study ranges from 1.071 to 2.241, and under the given conditions, all structures exhibit lower entropy generation compared to the original smooth microchannel. As the ratio of side riblet height to main riblet height increases, the heat transfer performance parameter improves and entropy generation decreases. However, increasing the valley width enhances temperature uniformity but results in a decrease in heat transfer performance and an increase in entropy generation. Additionally, structures with different side riblet peaks tilt were designed based on the C1 structure and subjected to investigation. Among these, the outward tilt of side riblet exhibits better heat transfer performance at low Reynolds numbers, whereas the C1 structure demonstrates superior heat transfer performance at high Reynolds numbers.