Lattice-Boltzmann两种非均匀网格算法及其对突扩流的模拟

Simulation of 2D Sudden-expansion Flow Based on Two Algorithms of Non-uniform Mesh Grids Using Lattice-Boltzmann Method

给出了Lattice-Boltzmann方法两种非均匀网格算法(即区域分裂方法和坐标变换方法)及计算步骤。对典型的突扩流问题进行了模拟分析,将所得结果与均匀网格进行比较分析。并对两种非均匀网格算法对流场模拟时进行了比较分析。区域分裂方法的优点在于区域划分过程灵活,对结构形状的要求低。坐标变换方法的优点在于只要对区域建立起合适的曲线坐标,计算过程简单,更节省时间。

Two non-uniform mesh grid algorithms （viz the methods based on domain decomposition technique and coordinate transformation technique） for the Lattice-Bohzmann method based on interpola- tion technique, with detailed calculation process, are presented. The simulation of the two-dimensional sudden-expansion flow was carried out in the current study, and the simulated results were then com- pared with the results calculated with the uniform mesh grid algorithm. At the same time, the contrast be- tween the two methods were also conducted during the process of simulation. The advantages of the method based on domain decomposition technique are that the flow domain can be divided flexibly and the method can be employed to structures with various shapes, while to the method based on coordinate transformation technique, a suitable curvilinear coordinate system should be established, and the process of calculation is simple, highly efficient in computation.