A non-iterative immersed boundary-lattice Boltzmann method with boundary condition enforced for fluid-solid flows

摘要

A non-iterative immersed boundary lattice Boltzmann method (IB-LBM) is proposed in this work for the simulation of fluid-solid flows. In the scheme, the interface is implemented by the correction of the neighboring distribution functions, similar to that of the LBM. Such treatment of the boundary is contrary to the traditional methods, where the interface is usually modeled as a generator of external force. Therefore, an advantage of the present method is to remove the efforts to evaluate the IB force and then incorporate it into the governing equation. Furthermore, an adjustment parameter is introduced to the immersed boundary scheme, which ensures the interpolated distribution functions derive the desired velocity at the boundary. Compared with the solution of a large boundary matrix and the multiple force correction that generally used in the previous studies, the present method is simpler and efficient without any iterative procedures. Those above-mentioned features make the present scheme based on the correction of the distribution function, with the enforcement of no-slip boundary condition. Simulation of flow past a fixed cylinder shows that there is no penetration of streamlines to the cylinder surface, indicating a well enforcement of the no-slip boundary condition. This scheme is further validated in the flows of a cylinder oscillating in a quiescent fluid, circular and elliptical particles settling in a channel. The results have good agreement with those data available in the literature. (C) 2019 Elsevier Inc. All rights reserved.