A vortex/impulse method for immersed boundary motion in high Reynolds number flows

A Lagrangian method that combines vortices and impulse elements (vortex dip oles) is introduced. The applications addressed are flows induced by the mo tion of thin flexible boundaries immersed in a two-dimensional incompressib le fluid. The impulse elements are attached to the boundaries and are used to account for the fords affecting the motion. The vortices occupy a region surrounding the boundaries and are used to account for the viscous effects via a deterministic diffusion method. The convergence of the method is dem onstrated numerically. The method is then used to track the motion of an un dulating filament, simulating the swimming of an organism in a slightly vis cous fluid. (C) 2000 Academic Press.