Experimental Investigations on the Vectoring Characteristics of the Axisymmetric Divergent Bypass Dual Throat Nozzle

Abstract

The greater thrust-vector angles can be obtained in the axisymmetric divergent bypass dual throat nozzle (ADBDTN). Meanwhile, the axisymmetric divergent bypass dual throat nozzle also has a certain flow adaptive capability and can solve the starting problems existing in the non-vectored state. In the present paper, the results of experimental investigations on the vectoring characteristics of the axisymmetric divergent bypass dual throat nozzle are given. By comparing the structures of the flow field obtained from experiments and numerical simulations as well as the wall static pressure distributions along the flow direction and circumferential direction, it can be seen that, as the nozzle pressure ratio (NPR) increases, flow reaches a critical state near the nozzle exit, and incompletely expanded flow in the cavity continues to accelerate after flowing out of the nozzle, a diamond-shaped structure with alternating shock and expansion wave systems appears downstream of the nozzle exit, and the flow field structures in the cavity are no longer changed when NPR ≥ 6. In addition, the static pressure distributions on the upper and lower wall surfaces of the cavity of the nozzle obtained from the experiments are in good agreement with the results of the numerical simulations, and the wall static pressures in the cavity are basically symmetrically distributed at various circumferential angles.