一个三维多松弛时间全速域格子Boltzmann模型

A Three-dimensional Multiple-Relaxation-Time Lattice Boltzmann Method for Whole-Speed-Range

  • 摘要: 构建一个既适用于低速不可压流体又适用于高速可压缩流体的三维自由参数多松弛时间格子Boltzmann模型.模型中,根据SO(3)群的不可约表述基函数构造转化矩阵,根据恢复可压Navier-Stokes方程的需要选取非守恒矩平衡值.通过von Neumann稳定性分析模型参数对数值稳定性的影响,并给出建议选择范围.模型经过基准问题的验证,模拟结果与解析解及其它数值结果符合较好.

     

    Abstract: A three-dimensional (3D) free-parameter multiple-relaxation-time lattice Boltzmann method for high speed compressible and low speed incompressible flows is presented. In the approach transformation matrix is constructed according to irreducible representation basis functions of SO(3) group. Equilibria of nonconserved moments are chosen so as to recover compressible Navier-Stokes equations through Chapman-Enskog analysis. Sizes of discrete velocities are flexible. Influence of model parameters on numerical stability is analyzed. Reference values of parameters are suggested. To validate performance of the model, several well-known benchmark problems ranging from 1D to 3D are simulated. Numerical results are in good agreement with analytical solutions and/or other numerical results.

     

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