Proposing Immersed Boundary-Lattice Boltzmann-Lattice Spring Algorithm for Simulation of 2-D Deformable Plate in Steady Flow

An immersed boundary-lattice Boltzmann method along with a lattice spring configuration is proposed. Fluid-solid interaction was accounted for by an additional force density in the lattice Boltzmann equation enhanced with the split-forcing approach. To analyze deformation of a flexible body, a robust lattice spring model is implemented. In this way, solid body is considered by collection of linear springs which are connected regularly inside the body. To reduce instabilities and limitation in selection of lattice spring length and time step, for the first time, we extended an implicit approach based on lattice Boltzmann-lattice spring method. Finally, flow and solid solvers are respectively validated by simulation of flow over a rigid plate and deformation of cantilever beam under axial and bending forces. Then, a deformable plate which is fixed in the middle is simulated. Results are also compared with the results of COMSOL’s software which show accuracy of the presented hybrid method. It is also shown that decreasing of the rigidity of the plate causes reduction of drag coefficient and retardation in initiation of the unsteady conditions.