Vortical Disturbances Produced by a Flat Plate Impulsively Rotated by 180 Degrees

Abstract

A discrete-vortex simulation has demonstrated that a flat plate being rotated 180° impulsively from its initial state, which is parallel to a uniform main flow, can produce isolated vortical structures. The rotation is around the mid chord, the trailing or the leading edge of the initial configuration. The vortical structures produced by the plate rotated in these modes are presented and discussed for a few typical values of the spin parameter. Especially the rotation around the trailing edge gives rise to a vortex pair travelling downstream. Paths of the vortical structures and their circulation as functions of the spin parameter for each mode of the rotation are also presented.