Mixing Characteristics of Supersonic Jet from Bevelled Nozzles

Abstract

The present study focuses on the effect of nozzle exit inclination on the mixing characteristics of Mach 2.17 overexpanded jets at the NPR 5, NPR 6 and NPR 7, using commercial software package ANSYS Fluent. The convergent-divergent nozzles, investigated are circular nozzle and bevel nozzle with bevel angle 300, and bevel angel 450. The nozzles are constructed with equal throat-to-exit area ratio, in order to maintain uniform Mach number at the nozzle exit. From the results, it was found that, the bevelled nozzles effectively reduce the jet core as much as 46%, indicating enhanced jet mixing. It was also observed that at lower NPR, i.e., at NPR 5, the Bevel30 nozzle is found superior over Bevel45 and circular nozzle and at the intermediate NPR, both of the Bevel30 and Bevel45 nozzle reduces the jet core with the same rate. However, at highest NPR of the present study, the Bevel45 nozzle exhibits the highest mixing enhancement. An early axis switching is seen for the Bevel30 jet at NPR 5 and for the Bevel45 jet at NPR 7.