Research on the control characteristics of multi-axis supersonic fluidic thrust vectoring nozzle based on the passive secondary flow

Fluidic thrust vectoring control technology has emerged as a critical solution for aircraft attitude control, demonstrating exceptional potential in propulsion-integrated design and flight performance enhancement. Existing supersonic passive ejector-type fluidic thrust vectoring nozzles predominantly employ 2D configurations, and thus are limited to single-axis pitch control. This study designed a multi-axis passive fluidic thrust vectoring nozzle, which feature a divergent section structure with eight circumferentially arranged secondary flow injection channels to achieve multi-axis thrust vectoring control. Through synchronized schlieren visualization and total pressure measurements, the shock wave structures and thrust vectoring characteristics were systematically investigated under diverse control modes. Experimental results demonstrate that at a nozzle pressure ratio (NPR) of 4.0, thrust vectoring control can be achieved in all 16 circumferential directions by selectively opening and closing secondary flow channels; As the number of closed secondary flow channels increases, the flow vectoring angle gradually increases. The maximum flow vectoring angle in the direction of primary control is 6°, and the linearity is 77.85%; the maximum flow vectoring angle in the direction of secondary control is 5°, and the linearity reaches 96%.