Time evolution of spanwise vorticity in the wake of a sphere moving in a stratified fluid

This image shows the spanwise vorticity at quarter shedding period intervals in the wake of a sphere moving horizontally in a stratified fluid. We can see the strong difference between the weakly buoyancy affected early part of the wake and the strongly affected intermediate to later region of the wake. The simulation was performed using large eddy simulation (LES) with a Reynolds number of 10,000, a Froude number of 3, and a Prandtl number of 1.