A LAGRANGE MULTIPLIER FICTITIOUS DOMAIN METHOD FOR THE NUMERICAL-SIMULATION OF INCOMPRESSIBLE VISCOUS-FLOW AROUND MOVING RIGID BODIES .1. CASE WHERE THE RIGID-BODY MOTIONS ARE KNOWN A-PRIORI

We describe in this Note a method for the numerical simulation of inco mpressible viscous how around moving rigid bodies; we suppose the rigi d body motions a priori known. The computational technique takes advan tage of a time discretization by operator splitting a la Marchuk-Yanen ko and of a finite element space discretization on a fixed mesh, to co mbine a Lagrange multiplier/fictitious domain treatment of the rigid b ody motions with an L-2-projection technique, to force the incompressi bility condition, The results of numerical experiments concerning flow around moving disks at Reynolds number of the order of 100 are presen ted.