不带稳定翼飞船返回舱俯仰动稳定性研究  

Study of the dynamic stability of a pitching unfinned reentry capsule

作　　者：张涵信[1] 袁先旭[1] 谢昱飞[2] 叶友达[2] 

机构地区：[1]国家计算流体力学实验室,北京100083 [2]中国空气动力研究与发展中心,四川绵阳621000

出　　处：《空气动力学学报》2004年第2期130-134,共5页Acta Aerodynamica Sinica

基　　金：国家自然科学基金资助项目(10032060).

摘　　要：联盟号飞船返回舱,如果不存在稳定翼,从高超声速到低Mach数时,力矩曲线有由一个平衡迎角(α1),经二个(α1、α′2)到三个(α1、α2、α3)平衡迎角的情况出现。当有一个平衡迎角时,可能有一临界Mach数Mcr,当M∞>Mcr时,平衡迎角处是动稳定的;M∞<Mcr,变为动不稳定的,同时出现极限环。也可能不存在这个Mcr,这时随Mach数降低到M∞=M′cr,即2个平衡迎角的情况,在力矩曲线与α轴相切的平衡点α′2,会出现鞍、结点分叉。M∞<M′cr后,对于存在三个平衡点的情况,在α和 α的相图上,它是结点-鞍点-结点的结构。当α1处是稳定结点形态时,只有在很小的扰动情况下,它才能返回α1的状态。如果α1为不稳定结点状态,在α1附近,微小的扰动,使迎角由α1迅速变成α3或者更大。这是混沌的先兆。For the Soyuz reentry capsule without stabilizing fins, when the freestream speed reduces from hypersonic to low Mach number, the capsule's pitching moment curve has one (α1), two (α1, α2), until three trim angles of attack (α1, α2, α3) successively. When there is one trim angle of attack, there probably exists a critical Mach number Mcr. The trim angle of attack is dynamic stable for M∞>Mcr, and will become dynamic unstable for M∞cr, and a limit cycle oscillation will occur at the same time. If this Mcr does not exist, then with the decrease of Mach number to M∞=Mcr, the moment curve is getting tangent with the αaxis at α2', i.e. the number of trim angles of attack becomes two. In this case, a saddle-and-node bifurcation happens. When M∞cr, in which case three trim angles of attack exist, the phase portrait of α and α is a node-saddle-node structure. When α1 is a stable node, only in the condition of very small perturbation, will the trace return to α1. When α1 is an unstable node, tiny perturbation in its neighborhood will make the angle of attack deviate from α1 quickly to become α3, or even larger. This is the forecast of chaos.

关 键 词：稳定翼 飞船 返回舱 俯仰振荡 动稳定性 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程]