载人飞船返回舱的动稳定性

载人飞船返回舱动稳定性的地面模拟试验方法有强迫振动法、有限自由振动法、自由翻滚法和模型自由飞试验法。试验结果表明，在配平攻角区阿波罗返回舱除马赫数Ｍ＜０．７以外，一般都具有俯仰正阻尼特性。双子星座返回舱在配平攻角区，当Ｍ＜２．５时存在俯仰负阻尼特性。钝头气流分离效应、后体气流再附效应、船尾近尾流效应和动态时滞效应等对静、动稳定性都有相反效应。这些效应会使返回舱的静稳定性增加，而使动稳定性降低。角振幅增大会使返回舱的平均俯仰阻尼增加，马赫数增大使俯仰阻尼降低。

THE DYNAMIC STABILITY CHARACTERISTICS OF CAPSULE TYPE Re-ENTRY VEHICLES

The dynamic stability characteristics of reentry modules of manned spacecrafts were determind using four test techniques, those were forced oscillation technique. limited free oscillation technique, free-totumble test technique and free flight test technique.In the at trim angle of attack region, the test results indicate that the Apollo CM generally has positive damping except at M<0.7. The Gemini reentry module has negative damping in the al region at M<2.5.The blunt nose induced flow separation effect, the aft body flow reattachment effect,the boat-tail hear wake effect and the dynamic time lag effect are the opposite effects on static and dynamic stability.These effects causes increased static stability and decreased dynamic stability.The average effective pitch damping increases with increasing angle of oscillation amplitude and decreases with increasing Mach number.