Corrected finite element methods on unfitted meshes for Stokes moving interface problem

Abstract

We propose an explicit in time corrected finite element method for a problem with a moving elastic interface in Stokes flow, using unfitted meshes and standard finite element approximation spaces. Piecewise polynomial correction functions are computed to accurately capture the discontinuities of the solution resulting from the elastic force applied to the fluid and are used to correct the load vector. The method is proven to be optimal for the steady state problem. Additionally, we propose a trigonometric interpolant to approximate and evolve the interface and explicit Euler scheme to advance in time. Numerical examples demonstrate the third and second order accuracy of the method for the velocity and pressure, respectively, and the stability of the numerical scheme.