Simulation method of microscale fluid-structure interactions: Diffuse-resistance-domain approach
Phys. Rev. Fluids 10, 094001 – Published 2 September, 2025
DOI: https://doi.org/10.1103/8xz3-2r3b
Abstract
Direct numerical simulations (DNS) of microscale fluid-structure interactions (mFSI) in multicomponent multiphase flows pose many challenges, including the thermodynamic consistency of multiphysics couplings, tracking of moving interfaces, dynamics of moving triple-phase contact lines, and the coupling of multiphase hydrodynamics with phase transition dynamics. We propose and validate a generic DNS approach: diffuse-resistance-domain approach. It overcomes the above challenges by employing Onsager's variational principle to formulate dynamic models and combining traditional diffuse-interface models for fluid-fluid interfacial dynamics with a novel implementation of complex fluid-solid interfacial conditions via smooth interpolations of dynamic-resistance coefficients across interfaces. After careful validation by numerous benchmark simulations, we simulated several cutting-edge, challenging mFSI problems across diverse fields. This generic DNS approach offers a promising tool for elucidating physical mechanisms, manipulating microscale fluid dynamics, and optimizing engineering processes across diverse fields.
