基于Broyden法的旋翼多体系统气动弹性分析

 建立了旋翼多体系统气动弹性模型并给出了一种适合于该模型响应计算的数值计算方法。采用柔性多体系统动力学方法建立旋翼气动弹性模型,利用驱动约束显著简化约束方程形式,集成大变形桨叶模型,准确考虑变形的非线性,适合于对采用柔性结构的先进旋翼进行气动弹性分析。基于Broyden法改进隐式积分法积分一步中非线性方程的求解,避免求取切线矩阵和矩阵求逆运算,保持隐式积分法具有较好稳定性的同时提高计算效率,解决了旋翼多体系统气动弹性力学方程隐式表达且具有较强非线性和较高刚性比造成的响应计算困难。通过模型旋翼桨叶响应计算验证了结构模型与气动弹性响应求解方法。采用建立的气动弹性模型计算悬停和前飞状态旋翼气动弹性稳定性,与试验结果对比验证了模型的正确性。研究了不同的稳定性计算方法、桨叶结构模型和入流模型等对悬停和前飞稳定性计算的影响,结果表明本文所采用的结构、气动模型及气动弹性稳定性计算方法提高了气动弹性稳定性分析精度。

Aeroelasticity Analysis of Rotor Multibody System Based on Broyden Method

An aeroelasticity model of a rotor system and its simulation method are developed. Based on the dynamics of flexible multibody systems, an aeroelastic model of a rotor is deduced. The driving constraint method is adopted to simplify the constraint equations and realize the reduction of system equations. A large deflection blade model, including all the nonlinear terms of the deformation, is incorporated, which is suitable for the aeroelastic analysis of the rotor. According to the nonlinear implicit expression and high stiffness ratio of the system equations, an implicit integration algorithm combined with the Broyden method is developed, which exhibits excellent numerical stability and good computational efficiency without calculating the Jacobi matrices and their inverse matrices. To verify the correctness of the developed method, the transient analysis of a model blade and the aeroelastic analysis of a model rotor are implemented. The influence of the stability analysis methods, blade structure models and inflow models on computation is also studied. It demonstrates that the developed method is useful for improving the computation precision of aeroelastic stability.