Thermodynamic consistency of the pseudopotential lattice Boltzmann model for simulating liquid-vapor flows
Thermodynamic consistency of the pseudopotential lattice Boltzmann model for simulating liquid-vapor flows
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DOI：
10.1016/j.applthermaleng.2014.03.030
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发表时间：
2014-11-05
影响因子：
6.4
通讯作者：
Luo, K. H.
中科院分区：
文献类型：
--
作者：
Li, Q.;Luo, K. H.
本文研究了赝势格子Boltzmann模型中状态方程对汽液两相流动的热力学一致性和界面厚度的影响。结果表明，随着汽相区状态方程斜率（θ（V））的增大，液滴尺寸对汽相密度的影响减小。从数值上可以看出，当汽相声速（根θ（V））与晶格声速（c（s））具有相同的数量级时，蒸汽密度通常可以保持在其平衡值附近。因此，为了实现物理上一致的模拟，气相声速应该与晶格声速相当。此外，赝势LB模型中的界面厚度被发现与机械不稳定区域中的状态方程的斜率（theta（M））有关。结果表明，当需要加宽界面厚度以减小寄生电流时，应减小垂直栅θ（M）。(C)2014作者爱思唯尔有限公司出版
In this paper, the effects of the equation of state on the thermodynamic consistency and the interface thickness are examined in the pseudopotential lattice Boltzmann modeling of liquid vapor flows. It is shown that, with the increase of the slope of the equation of state in the vapor-phase region (theta(V)), the influence of the droplet size on the vapor density can be reduced. Numerically, it is found that, when the vapor-phase sound speed (root theta(V)) is of the same order of magnitude as the lattice sound speed (c(s)), the vapor density can be generally kept around its equilibrium value. Hence, to achieve thermodynamically consistent simulations, the vapor-phase sound speed should be comparable with the lattice sound speed. Furthermore, the interface thickness in the pseudopotential LB modeling is found to be related to the slope of the equation of state in the mechanically unstable region (theta(M)). It is shown that vertical bar theta(M)vertical bar should be decreased when the interface thickness needs to be widened to reduce the spurious currents. (C) 2014 The Authors. Published by Elsevier Ltd.