基于CBS方法和ANCF的钝体—柔性尾板流固耦合数值分析方法

Numerical Method of Fluid-Structure Interaction for Bluff Body with a Flexible Splitter Plate Based on CBS and ANCF

以刚性钝体—柔性尾板为研究对象,提出了准确考虑刚柔多体结构复杂运动与变形的流固耦合数值分析方法。基于任意拉格朗日-欧拉方法,采用特征基分裂的有限元方法求解流体控制方程;基于绝对节点坐标法精确模拟柔性尾板的复杂大变形特征;利用顺序流固耦合方法实现流体与结构的关联求解,同时利用径向基函数插值方法确保网格更新的质量。在固定方柱-柔性尾板和弹性支撑圆柱-柔性尾板算例中验证了数值模型的可靠性。将模型应用于弹性支撑圆角方柱-柔性尾板的流致振动二维数值模拟,探究流固耦合现象与规律。

The rigid bluff body with a flexible splitter plate is concerned,and a numerical approach for the simulation of the fluid-structure interaction is proposed,where the complex motion and deformation of rigid-flexible multi-bodies are accurately considered.From the view of an arbitrary Lagrangian-Eulerian scheme,the finite element method using characteristic-based split(CBS)is developed to solve the governing equation of fluid flow.Based on the absolute nodal coordinated formula(ANCF),the complex large-deformation characteristics of the splitter plate are accurately simulated.The sequential coupling method is used to achieve the correlation between the fluid and the structure,while the interpolation of the radial basis function is applied to ensure the quality of moving meshes.The reliability of the numerical method is validated in the numerical examples for flexible splitter plates behind a fixed square cylinder and an elastically mounted circular cylinder,respectively.The proposed method is applied to the two-dimensional flow-induced vibration of an elastically mounted rounded square cylinder with a flexible splitter plate,and fluid-structure interactions are discussed.