Swirler

In chemical industry in many cases moderate to strongly swirling flows are used to increase the tangential velocity and to enhance the mixing of the species.

The swirl number is normally used to characterize the swirl intensity of a swirled flow and is conventionally defined as the ratio of the axial flux of the angular momentum to the axial flux of the axial momentum. It is also possible to use a simplified definition of swirl number, e.g. the ratio of the average value of the magnitude of the tangential velocity to the average value of the magnitude of the axial velocity of the flow exiting the swirler.