共查询到17条相似文献,搜索用时 78 毫秒
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格子Boltzmann方法中的曲边界处理 总被引:2,自引:2,他引:2
研究了格子Boltzmann方法中实现曲边界条件的3种格式,对它们的精度和稳定性进行了分析和比较.通过二维Poiseuille流和等边三角域上空腔流的模拟,讨论了这3种格式的数值精度和稳定性. 相似文献
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本文提出了一种适用于流固耦合领域中任意复杂边界条件的lattice Boltzmann处理方法.该方法基于half-way反弹模型,在流固耦合处构建了一层虚拟边界,并结合有限差分的方法,获取虚拟边界上的变量值.改进后的方法确保了粒子反弹位置与宏观速度采集点的位置相同,计入了实际物理边界与网格线不重合时,偏移量对计算结果的准确影响,而且其适用范围被扩展到了任意静止或运动、平直或弯曲的复杂边界.文中研究了该方法在Poiseuille流、圆柱绕流和Couette流等经典条件下的边界处理能力,结果表明该方法与理论值符合良好,且当实际物理边界与网格线不重合时,与已发表文献中的结果相比,具有更高的精度. 相似文献
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An Effective Method on Two-Dimensional Lattice Boltzmann Simulations with Moving Boundaries 下载免费PDF全文
We propose a lattice Boltzmann scheme for two-dimensional complex boundaries moving in fluid flow. The hydrodynamic forces exerting on the moving boundaries are calculated based on a stress-integration method proposed before, but the extrapolation procedure is avoided, and the stability of this model is improved. The accuracy and robustness are demonstrated by numerical simulations of a circular particle settling in a twodimensional vertical channel. The numerical convergence is studied by varying the time-step and the dimensionless particle sizes. 相似文献
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分析格子Boltzmann方法中二阶精度的曲线边界处理方法.应用格子Boltzmann方法及其边界处理方法模拟1/4圆腔内的定常层流运动,引入流线图和等涡线图分析流场随Re数的变化.并且发现当Re数在10~100区间内变化时,随着Re数的增大,顺时针旋转流场的涡心位置偏离x轴的角度逐渐减小,而逆时针旋转流场的涡心位置偏离x轴的角度却越来越大. 相似文献
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Kai Li & Chengwen Zhong 《advances in applied mathematics and mechanics.》2016,8(5):795-809
This paper presents a lattice Boltzmann (LB) method based study aimed
at numerical simulation of aeroacoustic phenomenon in flows around a symmetric
obstacle. To simulate the compressible flow accurately, a potential energy double-distribution-function
(DDF) lattice Boltzmann method is used over the entire computational
domain from the near to far fields. The buffer zone and absorbing boundary
condition is employed to eliminate the non-physical reflecting. Through the direct numerical
simulation, the flow around a circular cylinder at $Re$=150, $M$=0.2 and the
flow around a NACA0012 airfoil at $Re$=10000, $M$=0.8, $α$=$0^◦$ are investigated. The
generation and propagation of the sound produced by the vortex shedding are reappeared
clearly. The obtained results increase our understanding of the characteristic
features of the aeroacoustic sound. 相似文献
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应用多GPU技术,将格子Boltzmann方法与大涡模拟相结合(LBM-LES),使用1.12×108网格,对雷诺数Re=4 000,倾斜角α=30°,吹风比M=0.5工况下的平板单孔射流进行了大规模高性能数值模拟研究.合理的定性与定量结果验证了LBM-LES模拟平板射流的有效性与可行性.使用上亿的计算网格捕捉了精细的湍流拟序结构,有利于主流与射流之间的掺混机理研究.此外,使用6个K20M GPU并行计算,模拟了71 680 LBM时间步长,仅耗时15 402秒,计算性能达到521.24MLUPS,即每秒更新5.212 4×108个网格点的数据. 相似文献
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The goal of this article is to study numerically the mixed convection in a differentially heated lid-driven cavity with non-uniform heating of the bottom wall. The velocity field is solved by a hybrid scheme with multiple relaxation time Lattice Boltzmann(MRT-LBM) model, while the temperature field is obtained by resolution of the energy balance equation using the finite difference method(FDM). First, the model is checked and validated using data from the literature. Validation of the present results with those available in the literature shows a good agreement.A good efficiency in time simulation is confirmed. Thereafter, the model has been applied to mixed convection in a driven cavity with non-uniform heating wall at the fixed Grashof number Gr = 106. It is found that, the heat transfer is weakened as the Richardson number is augmented. For Gr = 106, we note the appearance of secondary vortices at different positions of the cavity corners. 相似文献
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KIM Dehee KIM Hyung Min JHON Myung S. VINAY III Stephen J. BUCHANAN John 《中国物理快报》2008,25(6):1964-1967
In lattice Boltzmann methods, disturbances develop at the initial stages of the simulation, the decay characteristics depend mainly on boundary treatment methods; open boundary conditions such as equilibrium and bounce-back schemes potentially generate uncontrollable disturbances. Excessive disturbances originate from non-physical reflecting waves at boundaries. Characteristic boundary conditions utilizing the signs of waves at boundaries which suppress these reflecting waves, as well as their implementation in the lattice Boltzmann method, are introduced herein. The performance of our novel boundary treatment method to effectively suppress excessive disturbances is verified by three different numerical experiments. 相似文献
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