A high-precision aerodynamic load transfer method for fluid-solid coupling simulation

In numerical simulations of fluid-solid coupling based on partitioned method, the fluid and solid solvers utilize independent grids for computations, so the grids are typically non-matching at the coupling interface. Physical quantities such as aerodynamic forces need to be transferred at the interface, and their conservation is essential to the accuracy of the simulation solutions. To reduce the error of aerodynamic force transfer, this paper proposes a data transfer method based on local surface degradation and accurate cell integration. In this method, a generalized two-dimensional coordinate system is initially constructed based on the solid mesh. Subsequently, the fluid mesh is projected, and the intersection area is calculated to determine the contribution of the fluid cells to the solid nodal force. The method has been demonstrated to be effective in achieving accurate and efficient data transfer between non-matching meshes of varying types. Compared to the traditional method, the proposed method can essentially ensure the comprehensive conservation of force, facilitate near-zero error aerodynamic force transfer, and result in a smoother aerodynamic force distribution. Additionally, the error of the momentum can be reduced by more than one order of magnitude. Finally, the influence of different data transfer methods on the fluid-solid coupling results are evaluated through the simulations of Rotor67, STCF4 standard turbine and Hirenasd wing which indicate that the interface data transfer approach proposed in this paper is more precise in calculations of solid deformation and aerodynamic damping.