Density perturbations in the wake and internal waves

This image shows two isosurfaces of density fluctuation behind a sphere moving horizontally in a stratifed fluid. Blue indicates fluid that is heavier than its neighbors and red fluid that is lighter than its neighbors. The cross planes illustrate the behavior of internal waves transferring energy from the wake to the background. 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.