DNS and LES of decaying isotropic turbulence with and without frame rotation using lattice Boltzmann method
DNS and LES of decaying isotropic turbulence with and without frame rotation using lattice Boltzmann method
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DOI：
10.1016/j.jcp.2005.03.022
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发表时间：
2005-11
影响因子：
4.1
通讯作者：
Huidan Yu;S. Girimaji;Li-Shi Luo
中科院分区：
文献类型：
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作者：
Huidan Yu;S. Girimaji;Li-Shi Luo
本文的目的是评估格子Boltzmann方程(LBE)作为湍流直接数值模拟(DNS)和大涡模拟(LES)的计算工具的有效性。考虑了惯性系和旋转系中的衰减均匀各向同性湍流(HIT)。我们执行三类模拟。第一类涉及HIT的LBE-DNS。在惯性系中，研究了动能k的衰减指数、耗散率ε和能谱的低波数标度。LBE结果与已有的经典结果吻合较好。在湍流受帧旋转影响的情况下，LBE模拟证实了能量衰减率随Rossby数的增加而减小，因为旋转抑制了能量级联。其次，对惯性系中的衰减命中进行了LBE-LES。我们计算了动能衰减、能谱和流动结构。通过比较LBE-LES和LBE-DNS的结果，我们发现LBE-LES准确地捕捉到了显著的大尺度流动行为。我们发现LBE-LES中的Smagorinsky常数CS值应该小于传统的N-S大涡模拟方法中使用的典型值。最后，我们比较了LBE-LES和NS-LES对于HIT的结果，观察到LBE-LES模拟似乎更准确地保留了瞬时流场。我们的结果清楚地表明，LBE方法可以准确地捕捉到衰减HIT的重要特征，是一种潜在的可靠的湍流模拟计算工具。
The objective of the paper is to assess the effectiveness of the lattice Boltzmann equation (LBE) as a computational tool for performing direct numerical simulations (DNS) and large-eddy simulations (LES) of turbulent flows. Decaying homogeneous isotropic turbulence (HIT) in inertial and rotating frames is considered for this investigation. We perform three categories of simulations. The first category involves LBE-DNS of HIT. In the inertial frame of reference, the decay exponents of the kinetic energy k, the dissipation rate ε and the low wave-number scaling of the energy spectrum are studied. The LBE results agree well with established classical results. In the case of turbulence subject to frame rotation, the LBE simulations confirm that the energy decay rate decreases with Rossby number as the energy cascade is inhibited by rotation. Second, we carry out LBE-LES for decaying HIT in inertial frame. We compute kinetic energy decay, energy spectrum and flow structures. By comparing LBE-LES and LBE-DNS results, we observe that LBE-LES accurately captures prominent large scale flow behavior. We find that the Smagorinsky constant CSin LBE-LES should be smaller than the typical value used in traditional Navier–Stokes (NS) LES approaches. Finally, we compare the LBE-LES and NS-LES (of comparable order of numerical accuracy) results for HIT and observe that the LBE-LES simulations appear to preserve instantaneous flow fields somewhat more accurately. Our results clearly indicate that the LBE method can accurately capture important features of decaying HIT and is potentially a reliable computational tool for turbulence simulations.