考虑非定常气动力随机不确定性的气动弹性研究

The aeroelastic instability of air vechicle is a significant phenomenom of catastrophic failure, which should be avoided. Unertainty always exists when a theoretical method is applied to the aeroelastic stability analysis. The uncertainty of unsteady aerodynamics is characterized by stochasticity. It is more complicated and it takes more significant effect on the aeroelastic stability than the structural uncertainty. This program will be focused on the quantification uncertainty of stochastic unsteady aerodynamics. The uncertainty model of unsteady aerodynamics will be established, then the estimation for its uncertainty distribution will be presented. the stochastic space expansion method will be modified, which will be applied to analyze the influence of unsteady aerodynamic uncertainty with arbitrary distribution on aeroelastic stability.Consequently, a virtual ground aeroelastic test and a wind tunnel test of a wing section will be designed and carried out. In these tests, the uncertainty of unsteady aerodynamics will be estimated and the real aeroelastic stability boundary will be test, in order to verify the analysis method. The success of this program will be good theoretical and experimental foundations of unsteay aerodynamic and aeroelastic uncertainty quantification.

飞行器气动弹性失稳是一类严重的破坏现象，必须予以避免。采用理论方法分析气动弹性稳定性时，不确定性是客观存在的。非定常气动载荷本身具有随机性的特点，相对于结构参数而言，气动力参数计算复杂，不确定性较大，它对气动弹性稳定性边界的影响更为重要。本项目拟针对非定常气动力随机不确定性，建立合理的气动力不确定性模型，提出气动力不确定性分布的估计方法，改进随机空间展开的方法，针对一般分布规律的非定常气动力不确定性，定量分析其对气动弹性系统稳定性的影响。在此基础上，设计二元翼段地面半实物仿真的气动弹性实验和风洞实验，估计气动力不确定性，测量实际气动弹性系统稳定性边界的分布，验证理论方法。该项目的完成将为非定常气动力和气动弹性不确定性定量分析奠定一定的理论和实验基础。

飞行器气动弹性失稳是一类严重的破坏现象，必须予以避免。采用理论方法分析气动弹性稳定性时，不确定性是客观存在的。非定常气动载荷本身具有随机性的特点，相对于结构参数而言，气动力参数计算复杂，不确定性较大，它对气动弹性稳定性边界的影响更为重要。本项目针对非定常气动力随机不确定性，开展了如下研究：建立了不同层次的气动力不确定性模型，基于CFD气动力提出气动力不确定性分布的估计方法，估计了偶极子格网法气动力不确定度大小。发展了浸入式和非浸入式PCE方法定量分析其对线性颤振的影响。基于LB非线性气动力模型，发展了考虑气动力模型参数不确定性的失速颤振不确定性量化。结果表明气动力不确定性对气动弹性稳定性影响明显，尤其是非线性气动力模型参数，影响更为明显。在理论分析基础上，设计二元翼段失速颤振风洞实验，估计气动力不确定性大小，测量实际二元翼段失速颤振边界，验证理论方法。