The swirling force, also known as vorticity confinement in the fluid simulation literature, takes care of preserving billowing motions (vortices) by intensifying already existing vortices in a velocity (grid) field.

This results in more small scale turbulences. It may be worth noting that this force cannot generate new turbulences or vortices on its own but it really only acts on already existing billowing motions, turbulences or vortices in the velocity field (of the fluid dynamics for example).