Development of a Nozzle to Improve the Turning of Supersonic Coanda Jets

摘要

The hypothesis that shaping the jet velocity profile improved the thrust vectoring of supersonic Coanda jets was experimentally tested. A new nozzle design procedure, based on the method of characteristics, was developed to design a nozzle which delivers an arbitrary exit velocity profile. Such a nozzle was designed for a pressure ratio of 2.5, to provide a jet matched to a circular Coanda surface with radius equal to five jet thicknesses. The thrust vectoring of this nozzle was then compared to that of a convergent divergent nozzle over a range of pressure ratios from 1.5 to 3.5. It is concluded that supersonic nozzles provide greatly improved turning of Coanda jets, and that shaping the velocity profile further improves the thrust vectoring. (Author)