Experimental study of a confined jet thrust vector control nozzle

An experimental study of a confined jet thrust vector control (CJTVC) nozzle is described. A CJTVC nozzle uses secondary injection for controlling and vectoring an overexpanded, supersonic jet within a confining chamber of the nozzle. This chamber consists of a diverging region and a region downstream that reconverges to an orifice at the exit. The pressure in the jet confining chamber can exceed ambient pressure. In this study, axial thrust is shown to depend on primary pressure, whereas side force and thrust vectoring are shown to depend on primary pressure, secondary injection pressure, and secondary port area. Only a small amount of secondary flow, compared with primary flow, is required for thrust vectoring. Unstable operation is found to occur under some conditions.