An Unconditionally Stable Second-Order Robin Partitioned Method for Fluid-Poroelastic Structure Interaction

This research addresses unsteady fluid-poroelastic structure interaction (FPSI) problems by coupling the incompressible Stokes equations in the free fluid region with the fully dynamic Biot system in the poroelastic region. The method reformulates the original physical coupling conditions into equivalent Robin-type interface conditions and introduces an auxiliary interface variable as common Robin data shared by both subsystems, enabling unconditional stability.