吸气式高超声速飞行器俯仰/滚转耦合运动特性

针对一种类似SR-72构型的吸气式高超声速飞机开展了进气道通流状态下俯仰/滚转耦合运动相关研究。通过数值模拟获得了滚转单自由度静稳定性、动稳定性以及强迫俯仰/自由滚转运动下的两自由度耦合动稳定性，研究了飞行器转动惯量以及俯仰运动频率对耦合运动的影响，简要分析了耦合运动的机理。研究发现虽然此飞行器具有滚转静稳定性和动稳定性，但是在强迫俯仰/自由滚转运动过程中，滚转通道却出现了小幅度振荡与大振幅振荡交替出现的情况，最大滚转角超过70°。小幅度振荡出现在正弦俯仰振荡的上半周期，其振荡频率随轴向转动惯量增加而降低，幅值随俯仰振荡频率增加而增大；大振幅振荡出现在下半周期，其幅值基本不变，而振荡频率与俯仰振荡一致。这种现象基本不受惯性耦合作用影响，可以认为是由气动力主导的。

Characteristics of air-breathing hypersonic vehicle in force-pitch and free-roll coupling motion

In this paper, the pitch/roll coupling motion of an air-breathing hypersonic aircraft similar to the SR-72 configuration is studied. Through the numerical simulation, the static stability, dynamic stability and the two-degree-of-freedom coupling dynamic stability under the forced pitching/free rolling motion are obtained. The influence of rotary inertia and pitch frequency on the coupling motion is studied, and the mechanism of coupling motion is analyzed. It is found that although the model has both static and dynamic rolling stability, in the process of forced pitch/free rolling motion, small amplitude oscillations and large amplitude oscillations occur alternately in the rolling channel, the maximum roll angle exceeds 70°. The small amplitude oscillation occurres in the upper half period of the pitch oscillation, the oscillation frequency decreases with the increase of axial inertia, the amplitude increases with the pitching oscillation frequency. The large amplitude oscillation occurred in the lower half period of the pitch oscillation, the amplitude is basically unchanged, while the oscillation frequency is consistent with the pitch oscillation. This phenomenon is basically unaffected by inertial coupling, and can be considered to be dominated by aerodynamic forces.