Fluid structure interaction analysis of counter flow in a partially layered vertical channel of double deformable passages

Cooling of two parallel surfaces with different temperatures is encountered in marine equipment. This requires a compact heat exchanger of two separated fluids, which counts on the double-passage channel. The present study uses a flexible separator to isolate two vertical passages, each partially filled with a porous layer. The permeability of the porous layers (Darcy number, Da), Reynolds number of each passage, temperature ratio, and the modulus of elasticity of the separator are scrutinized. Finite element method with the coupled ALE approach is employed in the numerical treatises. Results show that the strain energy of the elastic separator promotes the overall performance of the heat transfer, where at Da = 10−4, the left wall Nusselt number elevates by 10.4% and that of the right wall by 16.25% when the separator is changed from rigid to a flexible one. As the porous layers meet high permeability, energy transfer from the hot surfaces to the cold fluid upgrades notably, where the Nusselt number increases by 138% for the left wall and 96% for the right wall when Da is increased from 10−5 to 10−1. It is found in a high permeable layer, the flexible separator showcases higher performance than the rigid separator.