Investigation of active flow control of jet deflection rate in passive secondary flow thrust vectoring nozzle

Jet deflection rate is an essential index in the research of thrust vector control technology. The vectoring deflection of the jet is an unsteady flow. In this study, a pulse jet actuator with adjustable frequency was used to control the flow field of the thrust vectoring nozzle. The experimental results show that the unsteady pulse jet with the same characteristic frequency as the separated bubble structure can effectively deflect and adhere to the wall. The deflection rate of the main jet is susceptible to the pulse frequency of the pulse jet, and the flow field can reach the optimal deflection rate only under the unsteady excitation of a specific frequency. The transient flow field results show that the vortex shedding frequency of the flow field can be effectively destroyed by the unsteady excitation of a specific frequency and can evenly distribute the Coanda wall pressure of the vectoring nozzle. This flow phenomenon can increase the pressure difference of the passive secondary flow, accelerate the deflection rate of the main jet, and reduce the deflection hysteresis caused by the separation bubble structure. In this study, the wall deflection rate of the thrust vectoring jet was studied by the active flow control of the unsteady pulsed jet.