A Particle Finite Element Solution for ALE RANSE Coupled Fluid-Structure Interaction Systems

摘要

A numerical model of an arbitrary Lagrangian-Eulerian (ALE) description of the Reynolds averaged Navier- Stokes (RANS) equations (ALE-RANS) is presented in this article to solve incompressible viscous turbulent flows. The fluid free surface and the fluid-structure interface of the fluid-structure interaction (FSI) problem are tracked accurately using a pure Lagrangian version of the ALE-RANS. The ALE capability of the numerical model avoids large element distortions by employing a moving mesh to achieve specified numerical accuracy and stability. A particle finite element method (PFEM) is implemented to spatially discretize the fluid domain and solve the ALE-RANS equations. The particle features of PFEM combined with the ALE capability of the numerical model provides an ideal algorithm to solve free surface flow and FSI problems where a Lagrangian track of the moving boundary is required. An extended universal wall function (EUWF) is presented to solve both static and moving boundary layer problems. Four numerical examples including a pure CFD with a backward facing step, a prescribed moving cylinder in a bounded domain, a fluid-object interaction simulation of a bridge deck, and fluid-structure interaction of a flexible flap are employed to demonstrate the predictive capability of the model developed.