Burgers vortex

In fluid dynamics, the Burgers vortex is an exact solution to the Navier–Stokes equations governing viscous flow. The Burgers vortex describes a stationary, self-similar flow. An inward, radial flow, tends to concentrate vorticity in a narrow column around the symmetry axis. On the same time, viscous diffusion tends to spread the vorticity. The stationary Burgers vortex arises when the two effects balance.