An Explicit-Correction-Force Scheme of IB-LBM Based on Interpolated Particle Distribution Function

In order to obtain a better numerical simulation method for fluid-structure interaction (FSI), the IB-LBM combining the lattice Boltzmann method (LBM) and immersed boundary method (IBM) has been studied more than a decade. For this purpose, an explicit correction force scheme of IB-LBM was proposed in this paper. Different from the current IB-LBMs, this paper introduced the particle distribution function to the interpolation process from the fluid grids to the immersed boundary at the mesoscopic level and directly applied the LBM force models to obtain the interface force with a simple form and explicit process. Then, in order to ensure the mass conservation in the local area of the interface, this paper corrected the obtained interface force with the correction matrix, forming the total explicit-correction-force (ECP) scheme of IB-LBM. The results of four numerical tests were used to verify the order of accuracy and effectiveness of the present method. The streamline penetration is limited and the numerical simulation with certain application significance is successful for complex boundary conditions such as the movable rigid bodies (free oscillation of the flapping foil) and flexible deformable bodies (free deformation of cylinders). In summary, we obtained a simple and alternative simulation method that can achieve good simulation results for engineering reference models with complex boundary problems.

Automated summary

In this paper, an explicit correction force scheme of the combined IB-LBM method was proposed to improve the numerical simulation of fluid-structure interaction. The method introduced particle distribution function and applied LBM force models to calculate interface force. A correction matrix was used to ensure mass conservation in the interface area. The method was validated through numerical tests and successfully simulated complex boundary conditions for both movable rigid bodies and flexible deformable bodies.