基于边界元方法的气动弹性降阶模型及仿真

传统气动弹性的时域计算耗费了大量时间,为了提高计算效率,本文发展了基于边界元方法的降阶模型技术。首先基于边界元方法建立非定常流场的求解模型,结合特征值分析技术建立了非定常气动力的低阶模型;然后,利用边界元方法建立了气动网格和结构网格之间的信息转换矩阵;最后将非定常气动力降阶模型和结构动力学方程联合,建立了气动弹性系统的低阶状态空间模型。将所发展的降阶模型方法应用于NACA0012翼型的非定常气动力求解中,结果表明降阶模型可以在保证原系统计算精度的同时提高了计算效率;将降阶模型技术应用到三维机翼的气动弹性响应计算中,在系统阶数仅为12阶的情况下可以得到与原系统一致的极限环响应,说明降阶模型技术在求解气动弹性问题中的巨大优势。

Reduced order model for aeroelastic simulation based on BEM method

In order to improve computational efficiency in aeroelastic solution,the reduced order model is developed by boundary element method (BEM).Firstly,the model of unsteady flow is constructed by BEM,and the lower order model is developed by eigenvalue analysis technology; Then,the data transfer matrix between aerodynamic and structural field is designed by using BEM for aerodynamic/structure coupled solution;And finally,the reduced order model of aeroelasticity is deduced by combining unsteady aerodynamic load model with structural dynamic equation.The lower order model of unsteady flow is performed on unsteady aerodynamic solution of a NACA0012 airfoil,the results show that this method can improve the computation efficiency as well as maintain the original system accuracy.The developed reduced order model technology is applied to simulate aeroelastic dynamic responses of a wing,and the consistent limit cycle oscillations with the original system are obtained even in the case of 12 order model,it illustrates that the developed techniques have superior accuracy and practicability in aeroelastic solution.