Experimental studies on mixing of two co-axial high-speed streamsg

Currently, the focus of attention in aerospace propulsion research has been on the development of advanced air-breathing propulsion systems like scramjets, air-augmented rockets, multimode engines for the hyperplane, etc. A crucial technical problem to be tackled in such systems is the enhancement of mixing between two highspeed gaseous streams. Various methods have been tried so far, but the field is still very much an open one. Tests conducted earlier on subsonic flow mixing have shown that large-scale secondary flows, and not viscous diffusion, are the key to quick, low-loss, efficient mixing. In this regard, a lobe-type, convergent-divergent, supersonic nozzle, named the "Petal" nozzle, was designed, fabricated, and tested. Near-complete mixing with low total momentum loss within a short mixing chamber of length to diameter ratio of 4.35 was achieved. © 1993 American Institute of Aeronautics and Astronautics, Inc.