A Splitting-free Vorticity Redistribution Method

We present a splitting-free variant of the vorticity redistribution method. Spatial consistency and stability when combined with a time-stepping scheme are rigorously proven. We show how to reduce the number of particles without affecting the method's consistency. The novel concept of small neighbourhoods significantly reduces the method's computational cost without sacrificing any accuracy. In numerical experiments the method showed second order convergence, one order higher than predicted by the analysis. The method's computational cost is about half of that of the fast multipole code used in the velocity computation.