Séminaire de Mécanique d'Orsay
Jeudi 20 janvier à 14h au LIMSI
Monolithic Variational Multiscale Method for Fluid-Structure Interaction with Anisotropic Adaptive Meshing
Elie Hachem
(and T. Coupez)
Mines ParisTech, Centre for Material Forming CEMEF, Sophia-Antipolis
This paper presents a new immersed volume method for solving rigid body motions. The proposed method is developed in the context of the monolithic formulation. It consists in considering a single grid and solving one set of equations with different material properties. A fast anisotropic mesh adaptation algorithm based on the variations of the distance function is then applied to ensure an accurate capture of the discontinuities at the fluid-solid interface. Such strategy gives rise to an extra stress tensor in the Navier-Stokes equations coming from the presence of the structure (rigid/elastic) in the fluid. The system is solved using a finite element variational multiscale (VMS) method, which consists in here of decomposition for the velocity, the pressure and the extra constraint fields into coarse/resolved scales and fine/unresolved scales. We assess the behaviour and accuracy of the proposed formulation in the simulation of 2D and 3D time-dependent numerical examples such as: vortex shedding behind an obstacle and unsteady flow around 3D helicopter.
Figure 1: Numerical simulation of unsteady flow around helicopter in forward flight
References :
[1] E. Hachem, B. Rivaux, T. Kloczko, H. Digonnet, T. Coupez, Stabilized finite element method for incompressible flows with high Reynolds number, J. Comp. Phys. 224 (2010) 8643–8665.
[2] T. Coupez, Metric construction by length distribution tensor and edge based error for anisotropic adaptive meshing, accepted in J. Comp. Phys. (2010).