细长三角翼摇滚运动数值研究

采用亚迭代耦合求解流体动力学方程和刚体动力学方程数值研究方法,建立流体与刚体运动耦合的无时间滞后的数值手段来分析研究飞行器非定常的耦合运动特征,预测失稳运动的发生与发展。研究表明:在流动结构失稳后机体运动逐步形成极限环振荡的周期性自维持运动,滚转力矩系数滞回曲线呈现典型的”双8”稳定形态,前缘涡的非对称飘起与再附是典型三角翼摇滚的驱动形式;三角翼构型的自由滚振幅随攻角变化呈现阶跃式的变化;自激振荡的幅度及频率与滚动惯量的大小存在对应的规律性关系。非定常自激振动的翼摇滚具有多控制参数、非稳定、非线性的运动特征。

Numerical research on rock characteristic about a slender delta-wing

A coupling numerical method without time-lag is established by sub-iterative solving the fluid dynamics equations and the rigid-body dynamics equations synchronously in order to predict the onset and the development of uncommanded motions and then explore the unsteady movement characteristics of aerocraft.It is shown that the motion works up to a self-maintained stable Limit Cycle oscillation after the flow structure becomes unstable and that roll moment vs. roll angle during a whole cycle is in a typical stable "double 8" form.Liftoff and reattachment of leading-edge vortex is a typical driving model of wing rock.The roll oscillation amplitude with an increasing incidence angle after the onset takes on a jumping variety.The characters of self-excited oscillation such as the amplitude and the frequency are closely connected with the magnitude of roll inertia.In a word,unsteady self-induced wing rock is multi-parameter,unstable and nonlinear.