An explicit velocity correction-based immersed boundary-hybrid lattice Boltzmann flux solver for fluid-structure interaction with large solid deformation

Abstract

In this work, an explicit velocity correction-based Immersed Boundary-Hybrid Lattice Boltzmann Flux Solver (IB-HLBFS) is developed for Fluid-Structure Interaction (FSI) problems with large solid deformation in two-dimensional. The fluid domain is solved by the Lattice Boltzmann Flux Solver (LBFS) while the solid domain is solved by the Smoothed Point Interpolation Method (S-PIM). For coupling the two methods, the Explicit Velocity Correction (EVC) is developed and applied to both the fluid and the solid by implementing the Immersed Boundary Method (IBM). The fluid domain in IB-HLBFS can be discretized with non-uniform mesh so that the efficiency is improved meanwhile the accuracy is ensured compared with the original Lattice Boltzmann Method (LBM). Moreover, the explicit velocity correction simplifies the matrix inversion in the Implicit Velocity Correction (IVC) hence the efficiency is further improved. To show the advantages and the reliability of the present IB-HLBFS, the numerical simulations of flow past the elastic beam, flow past a circular cylinder with a flexible beam behind, and swimming of a self-propelled fishlike body are given to show the application of IB-HLBFS in FSI with complex fluid dynamics and large solid deformation. The results indicate that the present method is advantageous in terms of efficiency and accuracy, and has a wide prospect in engineering applications as well.