稳定性导数计算方法研究

稳定性导数的准确计算对于飞行器的操稳特性具有重要意义.应用计算流体力学(CFD)方法中的非结构化动网格技术建立能够模拟飞行器做周期性俯仰运动的强迫振荡法,以国际动导数标模Finner导弹为验证算例,获得不同马赫数下俯仰力矩系数的迟滞环曲线,进而计算Finner导弹在不同马赫数下的静稳定性导数和动稳定性导数.结果表明:本文计算得到的俯仰静稳定性导数与试验数据非常接近;在亚音速和超音速范围内,动稳定性导数计算结果与试验值很接近,但在跨音速范围内,本文计算结果与试验曲线的规律性一致,但误差较大.

study of calculating stability derivative

It is of significant importance to calculate the stability derivative accurately for stability and control of an aircraft. Dynamic mesh technology in computational fluid dynamics(CFD) are used to simulate periodic pitching oscillation motion of finned missile circling around a fixed axis. The hysteresis curve of pitching moment coefficient for the basic model Finner missile was obtained at different Mach number. The static derivatives of the missile in different Mach numbers were computed with difference method, line method and Least-square technique. The minimum error can be 0.5% compared with experimental data.; Dynamic stability derivatives were coumputed at different Mach numbers with integral method, Least-square technique and hysteresis-circle method. The error is between 5.8% and 23.8%. The results show that the method in the paper can correctly compute the static and dynamic stability derivative of finned missile and it can make a reference for engineers.