Fluid-structure interaction method using immersed boundary and lattice Boltzmann method

In order to apply lattice Boltzmann method (LBM) to aeroelastic analyses of the civil structures, a fluid-structure interaction (FSI) algorithm based on immersed boundary-lattice Boltzmann (IB-LB) method was presented in this paper. In the present algorithm, large eddy simulation was developed within the framework of multiple relaxation time lattice Boltzmann method to model the flow past the bluff body, and the Runge-Kutta method was used to solve the structural motion equations. In addition, an implicit IB method was adopted to implement the fluid-structure interface to satisfy the no-slip condition and improve the accuracy of the FSI algorithm. The aeroelastic simulations of a rectangular cylinder and the Forth Road Bridge were performed using self-developed codes. The results show that the lock-in phenomenon of vortex-induced vibration and the critical galloping velocity captured by the present algorithm for the rectangular cylinder are in good agreement with experimental data. Meanwhile, the study reveals that the present algorithm has a good prediction for the flutter onset velocity of the Forth Road Bridge.