Heat Transfer Enhancement of a Mini Channel Heatsink by Utilizing Flexible Beams Placed Downstream of a Cylindrical Obstacle

Abstract

Several studies have demonstrated that flexible vortex generators exhibit higher hydrothermal efficiency than their rigid counterparts. The present study focuses on the implementation of a cylindrical rigid obstacle located in the vicinity of the inlet of a mini channel. Downstream, several flexible beams are attached to the channel walls, oscillating due to the forces exerted by the Von-Karmann vortex street generated by the cylinder. The Reynolds number is sufficiently low to maintain a laminar regime throughout the mini channel. A parametric analysis is conducted to explore the performance of various configurations of flexible beams with differing numbers, heights, and inter-distances. The hydrodynamic, thermal, and hydrothermal performance of the mini channel is evaluated using the time average friction factor, Nusselt number, and thermal efficiency factor. Results indicate that the presence of flexible beams significantly enhances heat transfer. The best configuration increases the overall thermal efficiency by 45%, while elevating the heat transfer and mechanical loss by 3.05 and 8.52 times, respectively, in comparison with an empty mini channel.