基于格子Boltzmann方法的可压缩翼型绕流模拟

采用能够恢复可压缩Navier-Stokes方程的耦合双分布(DDF)格子Boltzmann方法(LBM)模拟了贴体网格下的NACA0012翼型绕流.首先在Ma＝0.5,α＝0.0,Re＝5 000状态下通过模拟低雷诺数流动检验了该方法;然后分别在Ma＝0.5,0.85和1.2,α＝-0.05,1.0和0.0状态下进行了模拟,并在Ma＝0.85时通过加密网格得到了更好的结果.为了避免转捩问题采用了无粘边界条件进行模拟,但得到的压力系数与实验结果吻合良好,证明了该方法的可靠性并显示了其模拟可压缩的潜力.该方法在翼型绕流上的应用为湍流流动的数值模拟提供了基础.

COMPRESSIBLE FLOW SIMULATION AROUND AIRFOIL BASED ON LATTICE BOLTZMANN METHOD

The flow around airfoil NACA0012 enwrapped by the body-fitted grid is simulated by a coupled double-distribution-function (DDF) lattice Boltzmann method (LBM) for the compressible Navier-Stokes equations. Firstly, the method is tested by simulating the low Reynolds number flow at Ma=0.5,α=0.0, Re=5 000. Then the simulation of flow around the airfoil is carried out at Ma=0.5, 0.85, 1.2; α=-0.05, 1.0, 0.0, respectively. And a better result is obtained by using a local refined grid. It reduces the error produced by the grid at Ma=0.85. Though the inviscid boundary condition is used to avoid the problem of flow transition to turbulence at high Reynolds numbers, the pressure distribution obtained by the simulation agrees well with that of the experimental results. Thus, it proves the reliability of the method and shows its potential for the compressible flow simulation. The successful application to the flow around airfoil lays a foundation of the numerical simulation of turbulence.