Computational Fluid Dynamics (CFD) Simulation and Experimental Validation of Heat Transfer Enhancement in Microchannel Heat Exchangers

Rahul Srinivasan, Vivek Sharma

Department of Mechanical Engineering & Finolex Academy of Management and Technology, Ratnagiri, India

1. Abstract

Microchannel heat exchangers (MCHXs) are recognized for their effectiveness in thermal management, attributed to their small size and substantial surface-area-to-volume ratio. A key challenge in MCHX design is to boost heat transfer while keeping pressure drops minimal. This research explores the enhancement of heat transfer through passive methods, including trapezoidal vortex generators and chevron-type ribs. Computational Fluid Dynamics (CFD) simulations were performed using ANSYS Fluent with the k-ω SST turbulence model, and the outcomes were experimentally validated with a specially constructed test rig. The research indicates that the chevron rib configuration enhances the average Nusselt number by 38%, whereas vortex generators achieve a 27% improvement over standard straight channels. This enhancement, however, results in higher pressure drops, highlighting the balance between thermal efficiency and pumping power. The experimental data closely align with CFD predictions, confirming the simulation method’s accuracy. These results offer valuable insights into optimizing microchannel designs for improved heat transfer without incurring substantial energy costs.

 Keywords

Heat transfer improvement in microchannel heat exchangers, CFD modeling, vortex generators, chevron ribs, experimental confirmation, Nusselt number, and pressure loss.