A decoupling algorithm for fluid-structure interaction problems based on optimization

Simulating fluid-structure interactions is challenging due to the tight coupling between the fluid and solid substructures. Explicit and implicit decoupling methods often either fail or require relaxation when densities of the two materials are close. In this paper, a fluid-structure interaction problem is formulated as a least squares problem, where the jump in velocities of the two substructures is minimized by a Neumann control enforcing the continuity of stress on the interface. A decoupling optimization algorithm is discussed, which requires few nonlinear solves at each time step, and numerical results are presented.