A Numerical Formulation to Study Interactions Between Fluids and Deformable Solid in Extension to Thin Film Geometries

In the present work, we use a fully Eulerian Level set method to track locations of the solid, solid strain, and calculate solid stress on the Eulerian grid. Stress-strain relationship of the solid is governed by the Neo-Hookean solid model. A unified framework of equation of motion is used to solve for both fluid and solid dynamics. Fluid-Structure Interaction is accounted for by adding a volumetric body force term in the solid region and the solid force is diffused into the fluid by a Heaviside function. Linear extrapolation has been used to reconstruct the solid strain field at the solid-fluid interface in prevention of the discontinuities. We first Validated our implementations by fully resolving the solid and comparing with existing literature results. We have then extended our implementations to thin film geometries by defining a thin region of solid of an order of a few computational cells where solid shear modulus quickly goes from solid value to zero. Numerical results are shown in this presentation.