适用于参数可调结构的非定常气动力降阶建模方法

发布时间：2019-05-09 12:35

【摘要】：基于计算流体力学(CFD)的非定常气动力降阶模型(ROM)可以极大提高气动弹性分析效率,然而现有的ROM只能针对固定参数结构,即只适合于固定模态振型,这使得现有ROM在气动弹性优化设计和不确定性分析等结构变参问题中应用受限。针对该问题,在文献[20]基础上提出了一种新的适用于任意模态振型的非定常气动力建模方法。首先将待设计/分析的结构进行参数化抽样和模态分析,之后通过主成分分析(PCA)得到若干基振型,再将这些基振型线性叠加即可拟合抽样空间内任何参数下结构的前若干阶振型。当结构参数改动时,仅仅是叠加系数发生变化。算例表明,仅用很少的基振型就能达到理想的拟合精度。经典的气动力降阶方法可用于基振型坐标下的气动力降阶,进一步变换可得到适用于不同结构的ROM,这意味着,结构参数可以在抽样空间内任意调节改动,而ROM却是通用的。该方法能广泛用于气动弹性优化设计和不确定性分析工作,可提高颤振分析精度和效率。
[Abstract]:The unsteady aerodynamic order reduction model (ROM) based on computational fluid dynamics (CFD) can greatly improve the efficiency of Aeroelastic analysis. However, the existing ROM can only be used for fixed parameter structures, that is, only suitable for fixed modal shapes. This makes the application of the existing ROM to the structural variable parameter problems such as Aeroelastic optimization design and uncertainty analysis limited. In order to solve this problem, a new unsteady aerodynamic modeling method for arbitrary modal modes is proposed on the basis of reference [20]. First, parametric sampling and modal analysis of the structures to be designed / analyzed are carried out, and then several fundamental modes are obtained by principal component analysis (PCA). Then the linear superposition of these fundamental modes can be used to fit the first order modes of the structure under any parameter in the sampling space. When the structural parameters are changed, only the superposition coefficient changes. The example shows that the ideal fitting accuracy can be achieved by using only a few basic modes. The classical aerodynamic reduction method can be used to reduce the aerodynamic order in the coordinates of fundamental modes. Further transformation can be used to obtain the ROM, for different structures, which means that the structural parameters can be adjusted arbitrarily in the sampling space, while the ROM is universal. This method can be widely used in Aeroelastic optimization design and uncertainty analysis, and can improve the accuracy and efficiency of flutter analysis.
【作者单位】：西北工业大学航空学院;
【基金】：国家自然科学基金优秀青年基金(11622220) 西北工业大学研究生创意创新种子基金(z2016002)~~
【分类号】：V211.3

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