Fully-Resolved Simulation of the Interaction between Flexible Blades and Oscillatory Flows

Interaction between flexible blades and oscillatory flows exists in many environmental problems, such as wind-canopy interaction in forest and wave-canopy interaction in salt marshes. We have developed a numerical tool for fully-resolved fully-coupled simulation of the interaction between flexible blades and oscillatory flows. Fluid phase is solved on Eulerian grid by direct numerical simulation, and flexible blades are solved on Lagrangian grid. Discrete immersed boundary method is adopted to consider the influence of blade motion on fluid, and hydrodynamic forces such as pressure and viscous stress are directly imposed on the blades instead of being modeled. Considering the relative density between the fluid and blade, strong or loose coupling between the fluid and blade solvers is selected for balancing calculation efficiency and robustness. The regime of flexible blade and oscillatory flow is studied based on the simulation results. The influence of various parameters such as the Cauchy number, Keulegan–Carpenter number and Reynolds number are investigated. The simulation result is compared with that modeled by the Morison formulation to check the effectiveness of Morison formulation under different scenarios.