NUMERICAL STUDY OF HEAT TRANSFER ENHANCEMENT BY DEFORMABLE TWIN PLATES IN LAMINAR HEATED CHANNEL FLOW

摘要

Fluid-structure interaction (FSI) of thin flexible plates involving large-scale flow-induced deformation is presented as a potential heat transfer enhancement technique. An in-house, strongly-coupled FSI solver is employed in which flow and structural solvers are based on sharp-interface immersed boundary and finite-element methods, respectively. Twin deformable thin plates in a heated channel are considered with laminar pulsating flow. Numerical simulations show that the vortex ring past the plates sweeps higher sources of vorticity generated on the channel walls out into the downstream--promoting the mixing of the fluid. The moving plates assist in convective mixing, augmenting convection in bulk and at the walls; thereby reducing thermal boundary layer thickness and improving heat transfer at the channel walls. The thermal augmentation is quantified in terms of instantaneous Nusselt number at the wall. Results are presented for two limiting cases of thermal conductivity of the plate--an insulated plate and a highly conductive plate. We discuss the feasibility and effectiveness of deformable plates and discuss the effect of important problem parameters--Young's modulus, flow frequency, and Prandtl number--on the thermal augmentation.