A Study on Swirl Flow in a Conical Diffuser. The Relationship between Turbulence and Plessure Recovery.

The purpose of this paper is to investigate the relationship between static pressure recovery and turbulent characteristic values of the velocity field, in the case where a swirling flow streams into a conical diffuser. We introduce a turbulent characteristic value which is obtained by intergrating the turblent energy over the sectional area of the diffuser. Results of our experiments show that the static pressure recovery depends strongly on the magnitude of the turbulent energy in the diffuser, and that this magnitude of the turbulent energy varies as the intensity of swirl at the diffuser inlet.