Effect of fin-enhanced microchannel structures on flow and heat transfer: comparison of triangular ribbed and corrugated designs

Conventional microchannels typically exhibit limited heat transfer efficiency and suboptimal flow characteristics. This study investigates two fin-enhanced microchannel geometries, triangular ribbed and corrugated, using a moving-grid method to simulate periodic fin motion. Numerical simulations were conducted over a Reynolds number range of 50–250 at a fin oscillation frequency of 20 Hz. The results show that the triangular ribbed microchannel offers lower flow resistance and improved overall flowability due to its relatively smoother flow path, whereas the corrugated design produces stronger flow disturbances and secondary vortices, leading to enhanced heat transfer, especially at lower Reynolds numbers. However, the intensified flow mixing in the corrugated microchannel also increases flow-path tortuosity, resulting in a larger pressure drop. To evaluate the overall performance, the Performance Evaluation Criterion (PEC) was used. The triangular ribbed channel achieved a maximum PEC of 1.52 at Re = 200, indicating a balanced improvement in both heat transfer and flow resistance. These geometries are relevant for practical thermal management applications, such as compact heat sinks and miniaturized cooling devices, due to their manufacturability and effectiveness in enhancing thermo-fluidic performance.