Crystallographic Lattice Boltzmann Method.
Crystallographic Lattice Boltzmann Method.
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DOI：
10.1038/srep27172
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发表时间：
2016-06-01
影响因子：
4.6
通讯作者：
Ansumali S
中科院分区：
文献类型：
--
作者：
Namburi M;Krithivasan S;Ansumali S
目前的直接数值模拟方法对于大多数流体动力学的实际科学和工程应用，如汽车或大气流动来说，在计算上是相当昂贵的。格子Boltzmann方法(LBM)以其简化的动力学描述成为模拟流体力学的重要工具。在异类计算环境中，由于其灵活性和更好的并行伸缩性，它通常是首选的。然而，在不使用湍流模型的情况下，直接模拟现实应用仍然是一个遥远的梦想，即使使用LBM这样的高效方法也是如此。在LBM中，考虑了速度空间中具有适当各向同性的虚拟格子来恢复宏观极限下的Navier-Stokes流体动力学。同样的格子被映射到笛卡尔网格上，用于动力学方程的空间离散。本文以空间离散化为中心，给出了LBM的一种倒置论证。我们认为，LBM的最优空间离散是体心立方(BCC)的网格点布置。我们展示了LBM在效率上的数量级增长，从而在现实流动中实现DNS的可行性方面取得了重大进展。
Current approaches to Direct Numerical Simulation (DNS) are computationally quite expensive for most realistic scientific and engineering applications of Fluid Dynamics such as automobiles or atmospheric flows. The Lattice Boltzmann Method (LBM), with its simplified kinetic descriptions, has emerged as an important tool for simulating hydrodynamics. In a heterogeneous computing environment, it is often preferred due to its flexibility and better parallel scaling. However, direct simulation of realistic applications, without the use of turbulence models, remains a distant dream even with highly efficient methods such as LBM. In LBM, a fictitious lattice with suitable isotropy in the velocity space is considered to recover Navier-Stokes hydrodynamics in macroscopic limit. The same lattice is mapped onto a cartesian grid for spatial discretization of the kinetic equation. In this paper, we present an inverted argument of the LBM, by making spatial discretization as the central theme. We argue that the optimal spatial discretization for LBM is a Body Centered Cubic (BCC) arrangement of grid points. We illustrate an order-of-magnitude gain in efficiency for LBM and thus a significant progress towards feasibility of DNS for realistic flows.