基于格子Boltzmann方法的超声速非平衡流模拟

基于D1Q4可压缩格子Boltzmann模型,按照流通矢量分裂方法的思路,采用坐标旋转技术构造求解三维带化学反应Navier-Stokes方程对流通量求解器.结合有限体积法求解三维化学非平衡流Navier-Stokes方程,采用时间算子分裂算法解决化学反应刚性问题,数值模拟超声速化学非平衡流的三个经典算例.数值结果表明:在高马赫数下,采用D1Q4可压缩格子Boltzmann模型构造的三维对流通量求解器数值模拟中没有出现非物理解,同时在超声速化学非平衡流场中正确分辨激波、燃烧波等物理现象,精度和分辨率均较高,验证了本文构造的三维对流通量求解器的可靠性,拓宽了D1Q4可压缩格子Boltzmann模型的应用范围,为计算超声速化学非平衡流提供一种新方法.

Supersonic Non-equilibrium Flow Simulation Based on Lattice Boltzmann Method

With ideas of vector splitting method and technique of coordinate rotation, a D1Q4 compressible lattice Boltzmann model is used to construct convection flux solvers of 3D Navier-Stokes equations with chemical reactions. Three-dimensional chemical non-equilibrium flow is solved by finite volume method of Navier-Stokes equations. A time-splitting method is applied to resolve stiff problem in computation of chemical reaction flows. Three classic examples of supersonic chemical non-equilibrium flows are simulated. It shows that:At high Mach numbers, numerical simulation using three-dimensional convection flux solvers based on D1Q4 model has no non-physical solution, and can distinguish physical phenomena such as shock, combustion wave in chemical non-equilibrium flow field. Accuracy and resolution are high,which verifys reliability of the three-dimensional convection flux solver. It broadens application of D1Q4 model, and offers a new method for calculation of hypersonic chemical non-equilibrium flows.