A coupled BEM and arbitrary Lagrangian-Eulerian FEM model for the solutionof two-dimensional laminar flows in external flow fields

This paper describes a new computational model developed to solve two-dimen sional incompressible viscous flow problems in external flow fields. The mo del based on the Navier-Stokes equations in primitive variables is able to solve the infinite boundary value problems by extracting the boundary effec ts on a specified finite computational domain, using the pressure projectio n method. The external flow field is simulated using the boundary element m ethod by solving a pressure Poisson equation that assumes the pressure as z ero at the infinite boundary. The momentum equation of the flow motion is s olved using the three-step finite element method. The arbitrary Lagrangian- Eulerian method is incorporated into the model, to solve the moving boundar y problems. The present model is applied to simulate various external flow problems like flow across circular cylinder, acceleration and deceleration of the circular cylinder moving in a still fluid and vibration of the circu lar cylinder induced by the vortex shedding. The simulation results are fou nd to be very reasonable and satisfactory. Copyright (C) 2001 John Wiley & Sons, Ltd.