轴对称矢量喷管有效喉道调节方法

基于三维雷诺平均Navier-Stokes方程对轴对称矢量喷管内流场进行了数值模拟,分析了不同落压比下轴对称矢量喷管有效喉道及流量系数随矢量偏转角的变化规律.研究发现:矢量偏转角超过一定值时,轴对称矢量喷管有效喉道位置发生倾斜,有效喉道面积减小,流量系数降低,矢量偏转角越大落压比越低,流量系数降低幅度越大.根据研究结果提出了一种针对矢量偏转状态的轴对称矢量喷管有效喉道调节方法,方法以落压比和矢量偏转角为输入参数,考虑了轴对称矢量喷管几何喉道面积调节前后流量系数的变化.该调节方法能够为发动机控制系统提供更精准的输入,提高控制精度,矢量偏转前后流量相差不超过0.4%,调节时间缩短至少10%,可为推力矢量发动机工作状态调节提供参考.

Adjustment method of effective throat for axisymmetric vectoring exhaust nozzle

Based on three-dimensional Reynolds-averaged Navier-Stokes equations, the interior flow field of axisymmetric vectoring exhaust nozzle was investigated numerically, and variation of effective throat and flux coefficient with vectoring deflection angles was analyzed at different nozzle pressure ratios. The results show that,when the vectoring deflection angle exceeds a certain value, effective throat position of the axisymmetric vectoring nozzle inclines, effective throat area reduces, and flux coefficient decreases with the increase of vectoring deflection angle and the decrease of nozzle pressure ratio. According to the results, an adjustment method of effective throat for axisymmetric vectoring exhaust nozzle used during nozzle vectoring is proposed by taking the nozzle pressure ratio and the vectoring deflection angle as input parameters; and the variation of flux coefficient is considered before and after adjusting the axisymmetric vectoring nozzle throat area. This method can provide a more accurate input for engine control system, improve the control accuracy with the flux variety less than 0.4%,and shorten by 10% of the adjustment time at least. The method can provide a reference for state regulation of thrust-vectoring engine.