摘要
采用非线性自治动力系统分叉理论,耦合求解非定常Navier-Stokes方程和俯仰运动方程,研究了再入飞行器单自由度俯仰运动失稳问题。研究表明,航天飞行器再入时,如果仅有一个配平攻角,随马赫数降低,其配平攻角处的俯仰动态失稳一般对应于Hopf分叉,并存在亚临界Hopf分叉和超临界Hopf分叉两种失稳形态。作为验证实例,数值模拟了飞船返回舱外形和平头有翼双锥外形的俯仰动态失稳现象。结果表明,返回舱再入时,随马赫数降低将发生超临界Hopf分叉,俯仰运动由点吸引子演化为周期吸引子,临界Hopf分叉点发生在马赫数2.2处;而平头再入体随马赫数降低,发生亚临界Hopf分叉,俯仰运动则是由周期吸引子演化为点吸引子,马赫数6.8为临界Hopf分叉点。
To study the problem about dynamic destabilization of the reentry vehicles, the bifurcation theory of nonlinear autonomous dynamic system is used together with the unsteady Navier-Stokes equations simulating the pitching process. The investigations shown that, the astronautic vehicles reentering into the atmosphere would generally occur a dynamic destabiliza- tion of pitching motion as their flight Mach number decreased, and the phenomenon of dynamic destabilization befallens at the point of the Hopf bifurcation, furthermore, there are two types of Hopf bifurcation named subcritical Hopf bifurcation and supercritical Hopf bifurcation. To vali- date the theory of the Hopf bifurcation, two reentry configurations are numerically studied. One is the Japanese capsule OREX, composed of a spherical cap facing forward and a reversed cone fa- cing backward. With Mach number decreases in the reentry process for the capsule, the pitching motion would evolve from a point attractor to a periodic attractor, and the critical Mach number is about 2.2 when the subcritical Hopf bifurcation occurs, the theory analysis and simulation re- sult is in good agreement with the experiment and flight test results. The other configuration is a flat-nose winged double-cone body, with the decrease of Mach number, its pitching motion would evolve from a periodic attractor to a point attractor, and the critical Mach number at which the supercritical Hopf bifurcation occurs is about 6.8.
出处
《空气动力学学报》
CSCD
北大核心
2015年第2期162-169,共8页
Acta Aerodynamica Sinica
基金
国家自然科学基金(11372341
912162001
11172315)
关键词
HOPF分叉
动态失稳
再入飞行器
非定常数值模拟
hopf bifurcation
dynamic destabilization
reentry vehiele
unsteady numericalsimulation
作者简介
袁先旭（1974-），男，研究员，研究方向：非定常空气动力学、飞行器动态特性．E-mail：yuanxianxu@mail．cardc．cn
通信作者：陈琦，男，助理研究员，研究方向：计算空气动力学．E-mail：chenqi@mail．ustc．edu．cn
