飞行器跨声速区俯仰力矩系数建模方法研究

飞行器气动力建模的准确性对其飞控系统设计、仿真和飞行性能分析有显著影响.在跨声速区马赫数变化对飞行器气动力影响显著,并且呈严重非线性,而在通常的气动力建模方法中却很少考虑马赫数的影响.本文对此问题进行了研究,根据某空空导弹和某返回舱俯仰力矩系数在跨声速区体现出来的特点,提出并建立了俯仰力矩系数随马赫数变化的概率函数模型.采用遗传算法辨识得到了某空空导弹和某返回舱的俯仰力矩系数建模结果,与风洞试验数据的比较表明,本文提出的概率函数模型确实比较好地描述了这些飞行器俯仰力矩系数在跨声速区随马赫数的变化规律.

Research on the modeling of pitching moment coefficient in transonic condition for flight vehicle

In transonic condition, aerodynamic coefficient was severely influenced by the change of Mach number. Because the accuracy of pitching moment coefficient model is very important to flight control system design, flight simulation, and flight performance evaluation, the modeling problem of pitching moment coefficient becomes very important and very difficult. This problem is studied in the present paper. According to the characteristic of pitching moment coefficient in transonic condition through wind-tunnel test results, a probability function model is proposed to describe the influence of Mach number to pitching moment coefficient in this paper, and the genetic algorithm is used as the modeling iterative algorithm. The modeling results of pitching moment coefficient for a certain air-to-air missile and a certain spaceship return capsule show that the probability function model proposed in this paper could describe the influence of Mach number to pitching moment coefficient very well.