激波诱导控制推力矢量喷管实验及数值计算

采用实验方法,通过在二元收敛-扩张喷管扩张段引入二次流喷射,开展了激波诱导控制的流体推力矢量技术研究.实验过程通过喷管上、下壁面压力测量及出口射流纹影观测,研究了主流压力、二次流喷射压力以及二次流喷嘴几何(缝或孔)对推力矢量喷管性能的影响.同时,结合数值计算方法,对各实验工况下的喷管流场进行数值模拟,获得了实验手段难以得到的流场数据和性能,对实验结果进行了辅助分析.初步研究结果表明:在给定的实验条件下,主流压力越高,喷管推力矢量角越小,同时推力系数越大;二次流压力越高,喷管推力矢量角越大,同时推力系数减小;同孔喷射相比,采用喷缝几何下的上壁面激波诱导分离点更趋于向上游移动,分离点后压升显著,射流穿透能力强,对主流的扰动强烈.

Experimental and numerical investigations of shock induced thrust vectoring nozzle

By inducting a secondary stream injection into the expanding part of a two-dimensional convergent-divergent nozzle model in the experiment, shock induced thrust vectoring technology was investigated. As the wall pressure distribution of the nozzle was measured and density field of the outflow was captured by schlieren, the effects of main stream pressure, secondary stream jet pressure and jet geometry(holes or a slot)on the performance of thrust vectoring nozzle was investigated. Numerical simulation method was used to calculate the flow field of the nozzle under different test conditions, and significant flow field data and performance parameters which were hard to capture by experimental method were obtained to analyze the test results as aid method. The investigation results indicated that: in the present conditions, with the increase of the main flow pressure, the angle of thrust vectoring is decreased and the thrust coefficient is added; with the increase of the secondary jet pressure, the angle of thrust vectoring is augmented and the thrust coefficient is descended; Compared with the jet hole, when the slot is applied, the separation point on upper wall is moved upstream due to induced shock. Moreover, the pressure is increased observably after the separation point, and the penetrabitity of secondary jet is strong, the effect of secondary jet on the main flow is intensified.