摘要
传统的颤振试飞主要通过计算多个不同飞行状态下的阻尼比,外推出颤振临界速度,该方法存在一定的风险。为此,发展了一种基于亚临界响应的高安全性颤振边界预测方法。该方法利用三维弹性机翼在气流中的一个亚临界响应,解算出作用在机翼上的非定常模态气动力系数。通过系统辨识获得与动压无关的非定常气动力模型,进一步通过流固耦合分析求解颤振临界特性。并以AGARD 445.6机翼的颤振边界预测为例,在仿真环境中验证了该方法的可行性。在此基础上,进一步研究了一个固定马赫数下响应测试动压与颤振临界动压的比值对预测精度的影响。
The most common approach to flight flutter testing is to track estimated modal damping ratios of an aircraft over a number of fight conditions, so it has a certain risk. In this paper, a high safety method for flutter boundary prediction is proposed based on a sub-critical response and the feasibility is proved by a numerical example of AGARD 445.6 wing in the simulation environment. A reduced order aerodynamic model with the dynamic pressure independent can be constructed through system identification by using only one structural response and the corresponding generalized unsteady aerodynamic force coefficient vector of a three dimensional elastic wing at subcritical speed, By further analysis of fluid-structure interaction, the critical flutter characteristics under the corresponding mach number can be predicted. On this basis, by decreasing the dynamic pressure of upstream at a fixed mach number, we studied the accuracy of the prediction along with the change of the ratio of dynamic pressure at the testing point to the flutter point.
出处
《飞行力学》
CSCD
北大核心
2015年第3期261-264,268,共5页
Flight Dynamics
基金
航空科学基金资助(20121353014)
陕西省"青年科技新星"计划资助(2014KJXX-36)
关键词
颤振预测
亚临界响应
系统辨识
颤振试飞
流固耦合
flutter prediction
sub-critical response
system identification
flutter flight test
fluid-structure interaction
