Asymmetric vortex merger in two dimensions: Which vortex is ‘‘victorious’’?

Abstract
Merger of two like‐signed vorticity monopoles is the chief mechanism for the emergence and growth of vortices in 2‐D turbulent flows. The merger processes in turbulent flows generally involve vortices of different size and vorticity amplitude. This normally causes one of the vortices to dominate. Results of a numerical survey are presented that determine which vortex is dominant or ‘‘victorious.’’ These results are obtained through the complementary use of a low‐order Hamiltonian moment model and a high‐resolution pseudospectral algorithm.