双喉道推力矢量喷管的内流特性研究

为了研究双喉道推力矢量喷管(DTN)在非推力矢量和推力矢量情况下的内流特性,基于数值模拟的方法,计算分析了不同几何参数和气动参数对DTN的影响。结果表明,DTN在非推力矢量时,仅在落压比(ZNPR)为3～4之间才具有较高的内流性能(推力系数达0.97,流量系数为0.94),当落压比增加时,推力系数迅速下降。在推力矢量时,DTN可以获得很大的推力矢量效率(当落压比为4,引射量为3%时达到4),且推力系数也较高(0.94以上),其综合性能优于单喉道偏移和激波操纵式矢量喷管。二次流量、落压比、凹腔扩张角和收敛角、引射角度都对推力矢量状态下的DTN内流性能有着不同的影响。为了实现DTN在推力矢量和非推力矢量下都有较好的内流综合性能,所建议的设计参数为:落压比为3～4,引射量为3%,凹腔扩张角为10°左右,收敛角在20°～30°,引射角度为30°逆流引射角(β=30°)。

Study of dual throat nozzle internal flow characteristic

The internal flow characteristics of dual throat nozzle(DTN) under vectoring and unvectoring thrust was studied by numerical simulation.The effects of several parameters on the internal flow were analyzed.The results show that DTN can achieve larger thrust vectoring efficiency with nozzle pressure ratio(ZNPR) only at 3~4 on unvectoring thrust state(thrust coefficient arrives 0.97,mass flux coefficient 0.94).But thrust coefficient decreases rapidly with ZNPR increase.On vectoring thrust state,DTN can achieve superior vectoring thrust efficiency(arrive 4 at ZNPR=4,secondary injection=3%),and large enough thrust coefficient(0.94).DTN has a superior overall performance than throat skewing nozzle and shock vectoring nozzle.The secondary mass flux,ZNPR,cavity convergence/divergent angle,and injection angle have different effect on internal performance of DTN.In order to achieve a tradeoff between vectoring and unvectoring state,the proposed parameters of DTN are: ZNPR=3~4,secondary injection flux is about 3%,cavity divergence angle is about 10°,cavity convergence angle is 20°~30°,injection angle of secondary is about 30° by counterflow injection.