Numerical simulation of the fluid and flexible rods interaction using a semi-resolved coupling model promoted by anisotropic Gaussian kernel function

The numerical simulation of the fluid flow and the flexible rod(s) interaction is more complicated and has lower efficiency due to the high computational cost. In this paper, a semi-resolved model coupling the computational fluid dynamics and the flexible rod dynamics is proposed using a two-way domain expansion method. The governing equations of the flexible rod dynamics are discretized and solved by the finite element method, and the fluid flow is simulated by the finite volume method. The interaction between fluids and solid rods is modeled by introducing body force terms into the momentum equations. Referred to the traditional semi-resolved numerical model, an anisotropic Gaussian kernel function method is proposed to specify the interactive forces between fluids and solid bodies for non-circle rod cross-sections. A benchmark of the flow passing around a single flexible plate with a rectangular cross-section is used to validate the algorithm. Focused on the engineering applications, a test case of a finite patch of cylinders is implemented to validate the accuracy and efficiency of the coupled model.