Optimization and thermodynamic analysis of rib arrangement and height for microchannels with sharkskin bionic ribs

Abstract

Here, four novel arrangements of microchannels with sharkskin-inspired bionic ribs were proposed to enhance heat transfer with a low pressure drop, as well as to reduce the irreversibility of flow and heat transfer compared to that in a smooth rectangular microchannel (SRM). The arrangements featured either equal (E) or non-equal (N) rib lengths and parallel (P) or staggered (S) rib positions, and were labeled as EP, ES, NP, and NS accordingly. The flow and heat transfer characteristics of these microchannels were then investigated in the laminar flow regime (Re = 50–1000). The results showed that NS performed the best overall at each condition, compared with EP, ES, and NP. Meanwhile, a performance evaluation plot showed that NS had the best energy savings and a large slope at H = 0.06 mm. Entropy generation analysis further confirmed that H = 0.06 mm was the optimum bionic rib height. The minimum enhanced entropy generation number, N s,a, for NS was 0.43 at H = 0.06 mm and Re = 770, indicating better energy utilization compared to other microchannels at this operating condition. The results from this study illustrate the potential of bionics in improving the design of microchannel structures.