Steady-State Solutions of the Euler Equations in Two Dimensions II. Local Analysis of Limiting V-States

Steady-state solutions of the 2D incompressible Euler equations (which we call V-states) are studied analytically. That is, a local expansion is done in the neighborhood of any point on the boundary of a V-state (which consists of piecewise constant regions of vorticity). The analytical results contained in paper I by Wu, Overman, and Zabusky are proven. In particular, the limiting V-states for the numerically calculated translating and rotating V-states have 90^∘ corners and not cusps. It is also proven that at a point which lies on the boundary of only one region and at which the tangent angle has a jump discontinuity then the difference in tangent angles can only be 90^∘ (a corner) or 180^∘ (a cusp). The analytical behavior of doubly and triply connected rotating V-states is also investigated.