Hydrodynamic interactions between two tandem flexible plates in viscous flow

A novel immersed boundary-lattice Boltzmann method(IB-LBM) is used to model the fluid-structure interaction problem with biologically flexible structure. In this algorithm, the fluid parameters are solved by LBM, while the boundary condition of structure are implemented by IB. Based on this framework, two tandem flexible plates pined in uniform viscous flow are simulated. The Reynolds number based on the incoming velocity and plate´s length are fixed at 300 and 500, but the separation distance are varied in a wide range. Simulation results show that the flexible plates will flapping passively when the flow field reach its stability. And the motion characteristic of downstream plate is strongly influenced by the vortex shedding from the upstream one. Also, we find the hydrodynamics on the tandem plates are strongly depended on the separation distance. As the distance increases, drag on the upstream plate is always smaller than single one. However, the downstream one will show two opposite situations. The findings of this work would be benefit for designing novel underwater robots.