An interface and geometry preserving phase-field method for fully Eulerian fluid-structure interaction

We present an interface and geometry preserving (IGP) method for modeling fully Eulerian fluid-structure interaction via phase-field formulation. While the time-dependent mobility model preserves hyperbolic tangent profile, proposed maintains of solid-fluid by minimizing volume-conserved mean curvature flow. To reduce flow, we construct a gradient-minimizing velocity field (GMV) convection order parameter. The constructed retains solid in domain while extending normal direction throughout diffuse region. With this treatment, GMV reduces difference isosurfaces parameter, alleviating undesired thickening or thinning region due to convection. As result, coefficient is substantially reduced there lesser Furthermore, ensures that moves with bulk despite fluid such fluid-solid conforms solid. Using unified momentum mass conservation equations phase-dependent interpolation, integrate IGP into solver based on incompressible viscous neo-Hookean models. kinematics frame reference resolved evolving left Cauchy-Green tensor. first demonstrate ability phase-field-based circular square interfaces prescribed field. variational framework then examined deformation block under cavity next explore geometry-preserving effect when flow passes over fixed deformable channel. Finally, vibration flexible plate attached behind stationary cylinder considered solving unsteady problems.