A coupled immersed boundary-lattice Boltzmann method with smoothed point interpolation method for fluid-structure interaction problems

The immersed boundary-lattice Boltzmann method has been verified to be an effective tool for fluid-structure interaction simulation associated with thin and flexible bodies. The newly developed smoothed point interpolation method (S-PIM) can handle the largely deformable solids owing to its softened model stiffness and insensitivity to mesh distortion. In this work, a novel coupled method has been proposed by combining the immersed boundary-lattice Boltzmann method with the S-PIM for fluid-structure interaction problems with large-displacement solids. The proposed method preserves the simplicity of the lattice Boltzmann method for fluid solvers, utilizes the S-PIM to establish the realistic constitutive laws for nonlinear solids, and avoids mesh regeneration based on the frame of the immersed boundary method. Both two- and three-dimensional numerical examples have been carried out to validate the accuracy, convergence, and stability of the proposed method in consideration of comparative results with referenced solutions.