摘要
对小曲率薄膜在均匀流场中的动力稳定性进行了分析。首先利用线性薄型机翼理论,将空气假定为二维的理想势流,用行波模拟薄膜振动形态推导了薄膜振动的特征方程,从而讨论了薄膜的失稳类型和失稳阶段。为了确定薄膜一阶失稳时的风速,进一步用涡旋面代替风与薄膜表面之间的微小厚度边界层来推导薄膜表面所受的气动力表达式;同时用有限形式的正弦波近似模拟薄膜一阶失稳构型,通过能量守恒原理和牛顿法迭代法求解薄膜振动的最大幅值;根据气动力与薄膜自重和惯性力之间的动力平衡关系获得了薄膜一阶失稳时的临界风速。
This paper deals with the vibration and the aerodynamic stability of small curvature membrane in uniform flow. Applying the linear airfoil theory and treating the air flow as two-dimensional ideal potential flow, the characteristic equation of membrane vibration is deduced by simulating membrane figure with traveling wave. Then instability type and phase of membrane is investigated. In order to determine critical wind velocity of membrane at first order instability, further vortex sheet on membrane is used to substitute the infinitesimal thickness boundary layer between wind and membrane surface, Expression of aerodynamic force is obtained; meanwhile, finite sinusoidal waveform is employed to simulate kinetic shape of membrane approximately. The maximum amplitude of membrane vibration is solved based on Hamilton principle and Newton＇s iterative method, The wind velocity of first order instability is obtained from the dynamic equilibrium relationship between aerodynamic force with dead weight and inertia force of membrane.
出处
《工程力学》
EI
CSCD
北大核心
2006年第4期39-44,51,共7页
Engineering Mechanics
关键词
薄膜
均匀流场
涡旋面
气动力
临界风速
membrane
uniform flow
vortex sheet
aerodynamic pressure
critical wind velocity
