Point vortex model for asymmetric inviscid wakes past bluff bodies

Abstract

Wakes past bluff bodies are modeled by means of point vortices standing in equilibrium. The consistency of the adopted model is discussed with respect to the asymptotic model proposed by Batchelor. It is shown that, in general, when symmetry is broken, the wake configuration may be neither closed, as for the Batchelor model, nor open, as for the Kirchhoff model. The proposed model has three degrees of freedom, which reduce to one when the locations of separation are prescribed. A further condition has been established for the closure of the wake which reduces the degrees of freedom to zero as for the asymptotic Batchelor model. The existence of multiple solutions, suggestive for real world phenomena, is discussed.