SIMULATIONS OF FULLY DEVELOPED CHANNEL FLOW BY A NEW HIGH-RESOLUTION SCHEME OF THE FINITE-DIFFERENCE LATTICE BOLTZMANN METHOD

摘要

This study deals with the aerodynamic noise caused by complex configurations of industrial products. Computational fluid dynamics (CFD) is useful approach to analyze radiated sounds and flows around them. The finite-difference lattice Boltzmann method (FD-LBM) is an expansion of LBM using the finite-difference discretization. It can implement on a body-fitted grid which has been preferably used under the view of computational cost and accuracy. Against huge computational cost in direct simulation of aerodynamic sound, FD-LBM has attained high resolution for sound wave. It is also important to handle turbulence with reasonable computational cost, for flows are often turbulent in engineering applications. We introduced a higher-order upwind biased scheme into the FD-LBM to achieve high resolution for turbulence. We also proposed a procedure to control down the artificial dissipation. We validated the schemes by the simulation of fully developed channel flow (R_τ ≈180). Satisfactory results were acquired on the resolutions which were used in direct numerical simulations with conventional CFD methods. The modification was efficacious against lack of resolution on coarser grids.