低速翼型绕流的多模态耦合与流动稳定性研究
Multi-Modal Interaction and Flow Instability of Flow around an Airfoil at Low Reynolds Number

采用非线性动力学理论对翼型绕流的多模态耦合机制进行研究,并阐释模态耦合作用与流动稳定性的关系。通过特征线有限元方法对翼型绕流问题进行数值计算,建立非定常流场数据库。为了分析流动稳定性和流动特征,利用本征正交分解提取流场中的特征模态,从而分析翼型绕流非定常流场的特征模态之间的相互作用关系,并给出了非线性流体动力系统中的不同模态作用与流动稳定性的关系。
Multi-mode interaction mechanism of flow around an airfoil is presented from viewpoint of nonlinear dynamics. The relationship between coupling effect and flow stability is studied. The flow around an airfoil is simulated using characteristics finite element method and then the database of unsteady flow field is established accordingly. In order to analyze flow stability and flow pattern, the dominant modes are extracted with Proper Orthogonal Decomposition. Furthermore, the interaction among the distinct modes of airfoil flow is analyzed, and the relationship between multi-mode interaction effect and flow instability in nonlinear fluid dynamic system is given