A monolithic approach for Fluid-Structure Interaction problems with complex geometries
Résumé
This talk summarizes advancements towards a monolithic formulation framework and anisotropic mesh
adaptation for fluid-structure interaction applications in complex geometry. First, a new stabilized three
field stress, velocity and pressure nite element formulation is presented for solving time dependent fluid-structure interaction between an incompressible fluid flow and a rigid/elastic body. Using a signed distance function (levelset) we add an extra stress tensor in the Navier-Stokes equations coming from the presence of the structure in the fluid. The distinctive feature of the proposed Variational MultiScale [1] approach is not only the decomposition for both the velocity and the pressure felds into coarse/resolved scales and fine/unresolved scales but also the possible efficient enrichment of the extra constraint. This choice of decomposition is shown to be favorable for simulating flows at high Reynolds number. Next, we combine this method with anisotropic mesh adaptation to ensure an accurate capture of the discontinuities at the fluid-solid interface and to resolve complex geometries [2].
We validate our approach by comparing its predictions with available data in the literature. We illustrate the flexibility of the proposed formulation in the simulation 3D turbulent flows behind immersed complex geometries inside wind tunnels. The flexibility of the approach resides in the possibility to vary easily the geometry by adding or removing small appendices in order to study their effects and to reduce eventually the turbulent behavior behind the immersed body.