Comparison of various fluid-structure methods for deformable bodies

A perspective is given on fictitious domain methods for deformable bodies that exert large motions induced by unsteady flow. In these methods an Eulerian and Lagrangian formulation are employed for the fluid and solid, respectively, and both bodies are coupled using a Lagrange multiplier. The use of a multiplier allows the solid not to be an integral part of the fluid mesh. Three variations of the fictitious domain method that have been published before, are compared to an ALE method in two numerical experiments and in conclusion the advantages, disadvantages and differences for the different approaches are discussed.