It can be generated by the entropy gradient associated with a curved shock, and like entropy, disturbances in this quantity travel through fluids at the flow speed, rather than the speed of sound.
The mean square value of this quantity is known as the enstrophy. It can be generated by the entropy gradient associated with a curved shock, and like entropy, disturbances in this quantity travel through fluids at the flow speed, rather than the speed of sound. When this quantity is zero throughout a flow, the flow is said to be a potential flow. The surface integral of this quantity over a surface bounded by a closed curve equals the circulation about that curve. Equal to twice the local angular velocity, FTP name this quantity given by the curl of the velocity in a fluid.
The mean square value of this quantity is known as the enstrophy.
{vorticity}