轴对称矢量喷管喉道运动学精确建模研究
Precision Kinematic Model for Throat of Axisymmetric Vectorexhaust Nozzle

轴对称矢量喷管中喉道面积大小影响战斗机的喷管性能，研究通常是以收敛调节片末端的内切圆表示其面积，该种表示在调节片数量不同的情况下导致存在不同程度的误差，不利于进一步进行定量分析。首先研究了喉道截面多边形的变化规律，建立了精确的喉道面积计算通用表达式；其次结合凸轮反转法和坐标转换，推导了适用于一般曲线截面的凸轮滚子喉道控制的运动学模型；最后建立实际算例，进行数值计算和虚拟仿真的验证。研究表明，数值计算与虚拟仿真结果吻合度较高，最大相对误差为0.79%，说明建立的运动学模型正确反映了喉道的运动规律。
Axisymmetric vector nozzle throat area has an important influence on the nozzle performance. Generally the inscribed circle of convergence adjusting piece end represents the throat area. Different errors exist for different number of adjusting piece, and the accuracy is not high enough for further quantitative analysis. In this paper, the characteristics of throat polygon were studied and the exact expression of throat area was deduced. The kinematic model of throat circle was established by utilizing cam inversion method and coordinates transformation. Numerical calculation and virtual simulation were conducted and compared for an example. The results of the numerical calculation and the virtual simulation agree well and the maximum relative error is 0.79%. It demonstrates the correctness of the established kinematic model of throat