Conjugate Heat Transfer Analysis of Microchannel with Slanted Elliptical Ribs

Abstract

This numerical study investigates the effect of slanted elliptical ribs (SERs) on pressure drop and heat transfer characteristics in a microchannel, within the context of developing solutions for heat transfer augmentation. In addition to a comparison with straight ellipsoidal ribs, other rib shapes with different angles of attack are examined. Key measures, such as pressure drop and average Nusselt number, are used to evaluate the performance of each design. The findings show that SERs significantly enhance heat transfer compared to smooth channels, primarily due to the chaotic advection induced by boundary-layer disturbances resulting from the ribs. With a 31.9% increase in average Nusselt number over the smooth baseline, design D3 exhibits the best thermal performance out of the twelve designs (D1–D12). Nevertheless, a rise in parasitic energy losses, which show up as greater pressure dips in SER-integrated channels, coincides with this improvement. The smooth channel exhibits the highest longitudinal temperature gradient, indicating significant non-uniformity, as determined by the temperature distribution study. SERs, on the other hand, encourage a more homogeneous temperature field; designs D2 and D10 exhibit the most consistent temperature profiles. While designs D2, D4, and D6 show relatively lesser penalties among the ribbed examples, pressure gradient trends further suggest that all SER configurations face higher-pressure drops than the smooth channel.