LARGE EDDY SIMULATION OF THE AERODYNAMIC DERIVATIVES OF BRIDGE USING LATTICE BOLTZMANN METHOD

In order to extend the application of Lattice Boltzmann Method (LBM) in simulating aerodynamic derivatives for bridges, the Wall-Adapting Local Eddy (WALE)-viscosity model is integrated into multiple relaxation time lattice Boltzmann method (MRT-LBM) and a new large eddy simulation-MRT-LBM-WALE, which is believed to effectively simulate high Reynolds flow past bridge structures, is proposed in this paper. The bridge decks undergoing sinusoidal oscillations in either the vertical or torsional degree of freedom are performed using MRT-LBM-WALE and the moving boundary technique. Using this approach, the forced vibration method for identification of aerodynamic derivatives is carried out in a virtual wind tunnel. A turbulent unsteady flow past a square column is analyzed to verify MRT-LBM-WALE. Subsequently, the aerodynamic derivatives of the thin flat plate and the Great Belt east bridge are calculated. The study reveals that MRT-LBM-WALE can provide precision prediction of turbulent flows due to the advantage that it can capture the real sub-grid eddy viscosity in near-wall region. In addition, the study shows that the simulation results of the aerodynamic derivatives obtained from MRT-LBM-WALE are consistent with analytical and experimental results.