1.3.6 Free-Lagrange method

Another deterministic vortex method is the free-Lagrange method developed by Börgers & Peskin [28], Rees & Morton [181], Russo [188], and Trease, Fritts & Crowley [224], among others. The basic idea is to construct a finite difference scheme for the derivatives using the Voronoi diagram [161] of the vortices. The computational effort to construct the Voronoi diagram is of the the same order as that of the convection of the vortices using fast algorithms [36,97,233] for example. Russo [188] has shown that the method does conserve vorticity and angular momentum but it is only weakly first-order consistent. Börgers and Peskin [28] have shown that the method requires a uniformity condition for the distribution of the points.