A locally implicit improvement of the equilibrium Eulerian method
A locally implicit improvement of the equilibrium Eulerian method
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DOI：
10.1016/s0301-9322(03)00064-8
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发表时间：
2003-06-01
影响因子：
3.8
通讯作者：
Balachandar, S
中科院分区：
文献类型：
--
作者：
Ferry, J;Rani, SL;Balachandar, S
平衡欧拉法是确定粒子分散系统速度场的一种简单方法。它避免了求解粒子速度的偏微分方程，这使得它比标准欧拉-欧拉方法更有效。它捕获了一些基本的色相物理，如优先浓度和湍流迁移效应，而这些被设置粒子速度等于流体速度的方法所忽略。虽然平衡欧拉法对小粒子很有效，但对太大的粒子就行不通了。本文对该方法进行了简单的改进，使较大颗粒的误差最小，从而扩大了该方法的适用范围。特别地，证明了改进的方法捕获了未修改方法所忽略的物理机制：粒子迁移到相邻流体层时保留的记忆。在湍流通道流动的直接数值模拟（DNS）中证明了这种改进，其中颗粒通过强剪切向壁面迁移。修正后的方法在不存在平均剪切的情况下也能很好地发挥作用：即各向同性湍流的DNS。2003爱思唯尔科学有限公司版权所有。
The equilibrium Eulerian method is a simple way to determine the velocity field of a disperse system of particles. It avoids solving a partial differential equation for particle velocity, which makes it more efficient than the standard Eulerian-Eulerian method. It captures such essential disperse-phase physics as preferential concentration and turbophoretic migration-effects which are ignored by methods that set the particle velocity equal to the fluid velocity. Although the equilibrium Eulerian method works well for small particles, it fails for particles that are too large. This paper presents a straightforward improvement to the method which minimizes the error for larger particles, thereby extending the method's range of applicability. In particular, it is demonstrated that the modified method captures a physical mechanism neglected by unmodified method: the memory a particle retains when it migrates to an adjacent layer of fluid. The improvement is demonstrated in a direct numerical simulation (DNS) of turbulent channel flow, where particles migrate toward the wall through a strong shear. It is also demonstrated that the modified method performs well in a case where no mean shear is present: a DNS of isotropic turbulence. (C) 2003 Elsevier Science Ltd. All rights reserved.