Numerical study of fluid-structure interaction for enhanced heat transfer in microchannels with an oscillating elastic wall

The present numerical study explores the performance of fluid-structure interaction (FSI) in a microchannel with an oscillating elastic wall. A two-dimensional (2D) Computational Fluid Dynamics (CFD) simulation was performed to investigate the influence of the elastic wall's frequency and amplitude on fluid flow behavior, pressure drop, and heat transfer enhancement. The FSI governing equations were solved using the Arbitrary Lagrangian-Eulerian (ALE) method. The results indicated that the Nusselt number (Nu) decreases as oscillation frequency increases. In contrast, the Nu increased linearly with the oscillation amplitude. Additionally, the Prandtl number (Pr) showed an insignificant influence on the Nu number for the studied operating range. An optimal operating condition was identified for the microchannel with an oscillating wall, achieving a spatial average Nu number of 16.796 compared to 14.577 for a simple microchannel channel, representing a 15.23 %% enhancement in heat transfer. A correlation is derived for the spatial average Nu number as a function of the Reynolds number (Re), Strouhal number (St), Pr, and vibration amplitude ratio, providing a valuable tool for designing and optimizing microchannel systems with FSI. Finally, the Maxwell boundary conditions are incorporated into the simulation of a microchannel with a vibrating upper wall to evaluate the slip conditions.