Laminar Flow Computation of Fish-Like Motion Wing

Flow around a fish is investigated by solving Navier-Stokes equations and the continuity equation numerically. The two dimensional wing which moves like a fish is considered as the simplest model. The motion has a transverse wave progressing along the body from head to tail and the amplitude of the wave increases from zero at the head to a maximum at the tail. The laminar flow field is solved for simplicity. The equation is discretized by first-order backward difference for time and the 5-point finite analytic of Chen and Patel for space. The pressure velocity coupling is accomplished by the SIMPLER algorithm. The moving body fitted grid system is used for the moving body and the grid is generated at each time step. The computational results show a very complicated vortical wake and flow field around the wing. The axial and lateral forces are also presented and discussed. The results for some other pattern movement show the essential feature of the fish like motion.