大展弦比机翼/外挂系统气弹响应的数值研究

Numerical Investigation on Aeroelastic Response of High-aspect-ratio Wing/Store System

综合考虑大展弦比机翼的几何非线性和外挂与机翼连接处的中心间隙非线性,建立了大展弦比机翼/外挂系统的气动弹性力学模型。采用非定常气动力,根据Hamilton原理推导了大展弦比机翼/外挂系统的运动微分方程。运用伽辽金法进行离散,通过数值模拟研究了系统的气动弹性响应及其稳定性。结果表明:中心间隙使系统出现极限环的起始速度明显降低;且在单稳极限环振动速度区间颤振幅值出现跳跃现象;随流速的增加,系统响应呈现出复杂的现象,如拟周期运动、周期运动与混沌运动相间出现、屈曲后颤振等。

Considering the geometric nonlinearity of high-aspect-ratio wings and the central free-play nonlinearity at the joint point,the aeroelastic mechanic model of high-aspect-ratio wing with store system is established. The motion equations of the system are deduced according to Hamilton principle based on unsteady aerodynamics. The equations are discretized by the Galerkin＇s method. The aeroelastic response and stability of the system are studied by numerical simulation. The results show that the critical speed of LCO decreases because of the effect of central free-play nonlinearity and the amplitude of LCO appears jumping phenomenon in the speed region of single LCO.With the increase of flow speed,the response presents complex phenomenon,such as quasi-periodical oscillation,periodic motion and chaos occuring alternately,flutter after buckling.