飞机机翼颤振特性测试仿真研究

Test simulation study on flutter characteristics of airfoil

为了减少颤振适航测量的工作量,使测试激振点的选取更有针对性,以B737-800为研究对象,提出了基于流固耦合的机翼颤振特性分析方法。该方法首先采用耦合流场计算机翼模态,然后将得到的耦合模态映射到机翼的谐波响应和瞬态动力学分析中,进而得到机翼的颤振特性规律,找出颤振危险点。分析仿真结果表明,机翼的变形主要位于22%~60%翼展区以及85%至翼尖处,与兰利研究中心颤振测量位置的选取一致,并且颤振测试仿真的扭转角沿半翼展方向的变化趋势也与兰利研究中心的测试结果相符,为机翼颤振失效分析及颤振适航测量的激振测试点的选取提供了一定的借鉴作用。

Aircraft stalling, air parking and airfoil flutter are three important factors that affect aircraft flight safety. It is always a critical issue in the field of flight data to fully carry out the flutter airworthiness measurement. To reduce the workload of flutter airworthiness measurement and to make the vibration test point selection more targeted, an analysing method aiming at the flutter characteristics of airfoils are proposed basing on fluid solid coupling, taking B737-800 as study object. Firstly, using coupled flow field to compute the wing mode, then by mapping coupled modes to the harmonic response and transient dynamics analysis of the wing, it would access to the regularity of flutter characteristics of the wing, thus the flutter danger points would he tbund out. Analysis of simulation results show that the wing deformation is mainly located in the 22%~60% wingspan area and 85% wingspan to wingtip, which is consistent with the selection of flutter measurement position in the research center of Langley. The changing trend of wing twist along semispan in flutter test simulation is matched with test results of Langley, thus it would provide reference for the analysis of wing flutter failure as well as the selection of excitation test points for the measurement of flutter airworthiness.