Lattice Boltzmann simulation of two cold particles settling in Newtonian fluid with thermal convection
Lattice Boltzmann simulation of two cold particles settling in Newtonian fluid with thermal convection
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热对流牛顿流体中两种冷粒子沉降的格子玻尔兹曼模拟
DOI：
10.1016/j.ijheatmasstransfer.2015.10.030
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发表时间：
2016-02
影响因子：
5.2
通讯作者：
Bo Yang, Sheng Chen, Chuansheng Cao, et al.
中科院分区：
文献类型：
--
作者：
Bo Yang, Sheng Chen, Chuansheng Cao, et al.
双颗粒沉降的知识在多相流研究中非常重要。然而，现有的研究几乎都局限于等温颗粒的沉降，其中颗粒与流体之间没有热对流。为了揭示热对流的影响，在目前的工作中，使用格子玻尔兹曼方法（LBM）和直接强迫浸入边界方法（IBM）研究了垂直通道中自由沉降的两个冷粒子的行为。通过改变两个冷粒子之间的初始分离距离和相对角度，还研究了这些初始参数对牛顿流体中冷粒子沉降相互作用的影响。在两个冷颗粒之间的初始分离距离和相对角度不同的情况下，我们发现在沉降过程中存在三种状态，即排斥、吸引和转变。通过比较两个冷粒子与其等温粒子的沉降，首次全面揭示了热对流对两个冷粒子之间相互作用的影响。结果表明，热对流显着影响沉降过程中两个冷颗粒之间的相互作用。由于热对流，排斥过程会增强，特别是当两个冷粒子彼此非常接近时。此外，我们观察到由于热对流，“牵伸、接吻和翻滚”（DKT）现象发生得更早。由于热对流，过渡态中的吸引和排斥过程得到增强。此外，热对流增强了两个冷粒子轨迹的振荡。
The knowledge on the sedimentation of double particles is important in multiphase flow research. However, the available studies almost all are limited on the sedimentation of isothermal particles where there is no thermal convection between particles and fluid. In order to reveal the effects of thermal convection, in the present work the behavior of two cold particles freely settling in vertical channel is investigated using the lattice Boltzmann method (LBM) with direct-forcing immersed boundary method (IBM). By changing the initial separation distance and relative angle between two cold particles, the effects of these initial parameters on the interaction of cold particles settling in Newtonian fluid are also investigated. With different initial separation distance and relative angle between the two cold particles, we find that there are three regimes, namely repulsion, attraction and transition, during the sedimentation. The effects of thermal convection on the interactions between the two cold particles are revealed comprehensively for the first time by making comparisons between sedimentation of the two cold particles and their isothermal counterparts. The results reveal that thermal convection significantly influences the interactions between two cold particles during the sedimentation. The repulsive process will be enhanced due to thermal convection especially when the two cold particles approach each other very close. In addition, we observe the “drafting, kissing and tumbling” (DKT) phenomenon occurs earlier due to thermal convection. Owing to thermal convection, the attraction and repulsion process in the transition regime are enhanced. Moreover, thermal convection enhances the oscillations of trajectories of the two cold particles.
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影响因子：
4.1
作者：
GOLDSTEIN, D;HANDLER, R;SIROVICH, L
通讯作者：
SIROVICH, L
影响因子：
4.5
作者：
Z. Hashemi;O. Abouali;R. Kamali
通讯作者：
Z. Hashemi;O. Abouali;R. Kamali
影响因子：
3.7
作者：
A. Fortes;D. Joseph;T. Lundgren
通讯作者：
A. Fortes;D. Joseph;T. Lundgren
影响因子：
2.8
作者：
Shin K. Kang;Y. Hassan
通讯作者：
Shin K. Kang;Y. Hassan
影响因子：
2.4
作者：
Guo, ZL;Zheng, CG;Shi, BC
通讯作者：
Shi, BC