Linear stability of a non-symmetric, inviscid, Kármán street of small uniform vortices

Abstract

The classical point-vortex model for a Kármán vortex street is linearly stable only for a single, isolated, marginally stable, case. This property has been shown numerically to hold for streets formed by symmetric rows of uniform vortices of equal area. That result is extended here to the case in which the areas of the vortices in the two rows are not necessarily equal. The method used is an analytic perturbation valid when the vortex areas are small, and applied using an automatic symbolic manipulator.