A bounce back-immersed boundary-lattice Boltzmann model for curved boundary

In this paper, a bounce back-immersed boundary-lattice Boltzmann model(BB-IB-LBM) is proposed for curved boundary.In the present model, a modified density distribution function is proposed for curved boundary including stationary and moving curved boundaries. A special treatment is also developed to satisfy no-slip boundary condition for the curved boundary with large curvature. On Lagrangian boundary points, the modified distribution functions are implemented to replace the artificial correction force in conventional immersed boundary-lattice Boltzmann methods(IB-LBMs). Numerical experiments are given to illustrate the accuracy and efficiency of present BB-IB-LBM. The drag coefficient of the test cases predicted by the present model is in better agreement with the results of experimental results than that of the previous IB-LBMs. It is also concluded that the average drag coefficient of present model are consistent with the experimental results. Comparing with conventional IB-LBMs, the present model eliminates the non-physical vortex at the tail of an airfoil. Simulation of flow over a sphere also proves the extensibility of present method in three-dimensional simulation.