发表机构
University of Wrocław; Jožef Stefan Institute; Czech Technical University in Prague（弗罗茨瓦夫大学; 约瑟夫斯蒂芬研究所; 布拉格捷克技术大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究基准测试了无网格LBM中多种无滑移边界条件，发现非平衡外推在精度和稳定性上最优，并强调在复杂问题中选择合适无滑移实现的重要性。
AI 中文摘要
将近似流式引入标准格子玻尔兹曼方法（LBM）中，使得空间离散与速度离散解耦。尽管许多已知的LBM无滑移实现可以直接应用于具有近似流式的模型，但它们在非格子环境中的确切行为仍未被探索。在本工作中，我们研究了配备多种无滑移实现的无网格非格子D2Q9模型——非平衡外推、简单和插值反弹、以及基于矩的边界——并将其应用于圆柱周围的斯托克斯流。我们比较了在极坐标和混合极坐标-散点离散上使用各种无滑移实现获得的压力、速度和速度梯度场。我们发现，非平衡外推在所有研究的无滑移实现中表现最佳，在固体壁上给出平滑的应力和零速度。其他无滑移实现则遭受流体动力学场中的振荡和/或不连续性。混合离散被发现比极坐标网格产生更高的误差，但提高了解的稳定性。最后，我们模拟了在研究的无滑移实现获得的应力下弹性环的变形，以强调在更复杂问题中对无滑移实现进行明智选择的重要性。
英文摘要
The introduction of the approximated streaming to the standard Lattice Boltzmann Method (LBM) decouples the space and velocity discretizations. Although many no-slip implementations knwon from LBM can be directly adopted to the models with approximated streaming, their exact behavior in the off-lattice setting remains unexplored. In this work, we investigate the meshfree off-lattice D2Q9 model equipped with several no-slip implementations -- non-equilibrium extrapolation, simple and interpolated bounceback, and moment-based boundaries -- applied to a Stokes flow around a cylinder. We compare the pressure, velocity and velocity gradient fields obtained with various no-slips, on polar and hybrid polar-scattered discretizations. We find that non-equilibrium extrapolation performs the best of all the studied no-slip realizations, giving smooth stresses and zero velocity on the solid walls. Other no-slips suffer from oscillations and/or discontinuities in the hydrodynamic fields. Hybrid discretizations are found to give higher errors than the polar grid, but improve the stability of the solution. Finally, we simulate the deformation of an elastic ring under the stresses obtained with the studied no-slips to highlight the importance of the sensible choice of the no-slip realization in more complex problems.
