Application of Approximate Unsteady Aerodynamics for Flutter Analysis

Abstract

A technique for approximating the modal aerodynamic influence coefficient (AIC) matrices by using basis functions has been developed. A process for using the resulting approximated modal AIC matrix in aeroelastic analysis has also been developed. The method requires the unsteady aerodynamics in frequency domain, and this methodology can be applied to the unsteady subsonic, transonic, and supersonic aerodynamics. The flutter solution can be found by the classic methods, such as rational function approximation, k, p-k, p, root locus et cetera. The unsteady aeroelastic analysis using unsteady subsonic aerodynamic approximation is demonstrated herein. The technique presented is shown to offer consistent flutter speed prediction on an aerostructures test wing (ATW) 2 and a hybrid wing body (HWB) type of vehicle configuration with negligible loss in precision. This method computes AICs that are functions of the changing parameters being studied and are generated within minutes of CPU time instead of hours. These results may have practical application in parametric flutter analyses as well as more efficient multidisciplinary design and optimization studies.

An automated aeroelastic performance prediction method in time domain for transonic aeroelastic tailoring

“…参数发生变化后, 依赖于结构模态振型进行气动弹性 性能预估的求解器需要重新构建气动弹性模型才能保 证评估精度, 因此在不改变基准结构模态坐标 [15] 情况 下通过构建自动化气动弹性预估方法建立气动弹性性 能评估求解器与设计参数之间有效的联系, 通过避免 大量的人工手动修改气动弹性模型过程来提高气动弹 性剪裁效率的一个极具有吸引力的可行策略 [16][17][18] . 结 构动力重分析技术可以利用现有的基准模态振型获得 结构参数变化后的结构模态特性, 在结构优化过程中 发挥着重要作用.…”