Process and Energy Department, Delft University of Technology, Leeghwaterstraat 39, 2628 CB Delft, The Netherlands.
Phys Rev E. 2018 Apr;97(4-1):043305. doi: 10.1103/PhysRevE.97.043305.
Various curved no-slip boundary conditions available in literature improve the accuracy of lattice Boltzmann simulations compared to the traditional staircase approximation of curved geometries. Usually, the required unknown distribution functions emerging from the solid nodes are computed based on the known distribution functions using interpolation or extrapolation schemes. On using such curved boundary schemes, there will be mass loss or gain at each time step during the simulations, especially apparent at high Reynolds numbers, which is called mass leakage. Such an issue becomes severe in periodic flows, where the mass leakage accumulation would affect the computed flow fields over time. In this paper, we examine mass leakage of the most well-known curved boundary treatments for high-Reynolds-number flows. Apart from the existing schemes, we also test different forced mass conservation schemes and a constant density scheme. The capability of each scheme is investigated and, finally, recommendations for choosing a proper boundary condition scheme are given for stable and accurate simulations.
文献中提供的各种曲线无滑移边界条件相比于传统的曲线几何阶梯近似可以提高格子玻尔兹曼模拟的准确性。通常，从固节点出现的所需未知分布函数是使用插值或外推方案基于已知分布函数计算的。在使用这种曲线边界方案时，在模拟的每个时间步都会出现质量损失或增益，尤其是在高雷诺数时，这被称为质量泄漏。在周期性流动中，这种问题会更加严重，因为质量泄漏的积累会随着时间的推移影响计算的流场。在本文中，我们研究了最著名的用于高雷诺数流动的曲线边界处理方法的质量泄漏。除了现有的方案外，我们还测试了不同的强制质量守恒方案和恒定密度方案。研究了每种方案的能力，最后给出了选择合适边界条件方案的建议，以实现稳定和准确的模拟。
