Lattice Boltzmann simulation of liquid flow in nanoporous media
Lattice Boltzmann simulation of liquid flow in nanoporous media
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纳米多孔介质中液体流动的格子玻尔兹曼模拟
DOI：
10.1016/j.ijheatmasstransfer.2018.04.123
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发表时间：
2018
影响因子：
5.2
通讯作者：
Sun Hai
中科院分区：
文献类型：
--
作者：
Zhao Jianlin;Kang Qinjun;Yao Jun;Zhang Lei;Li Zheng;Yang Yongfei;Sun Hai
本文建立了纳米级液体流动的多弛豫时间格子玻尔兹曼（LB）模型来研究纳米多孔介质中的液体流动特性。采用分子动力学（MD）模拟获得的滑移长度和有效粘度来解释纳米级效应。首先，建立了纳米孔内水流的LB模型，研究了纳米孔介质中的水流特性。流固相互作用力对纳米多孔介质中的水流具有显着影响。通过纳米多孔介质的水通量随着流固相互作用力的减小而增加。在疏水性纳米多孔介质中，纳米级效应可以减小大孔隙和小孔隙中水流阻力的差距，使速度分布更加均匀。此外，流线弯曲引起的末端效应会引起显着的附加流动阻力。忽略最终效应会大大高估水流能力。孔隙结构对纳米多孔介质中的水流也有显着影响。随着比界面长度的增加，纳米级效应增强。最后，结合MD模拟结果，建立了石英纳米孔内油（辛烷）流动的LB模型。石英纳米多孔介质中的油流模拟表明，针对水流获得的结论也适用于油流。
In this paper, a multi-relaxation-time lattice Boltzmann (LB) model for nanoscale liquid flow is established to investigate the liquid flow characteristics in nanoporous media. The slip length and effective viscosity obtained by molecular dynamics (MD) simulations are adopted to account for the nanoscale effect. First, the LB model for water flow in nanopores is built and water flow characteristics in nanoporous media are investigated. The fluid-solid interaction force shows significant influence on water flow in nanoporous media. The water flux through nanoporous media increases with the decrease of fluid-solid interaction force. In hydrophobic nanoporous media, the nanoscale effect can decrease the gap between water flow resistance in large pores and that in small pores, making the velocity distribution more uniform. In addition, the end effect caused by the bending of streamlines can induce significant additional flow resistance. Neglecting the end effect can greatly overestimate water flow ability. The pore structure also has significant influence on water flow in nanoporous media. With the increase of specific interfacial length, the nanoscale effect increases. Finally, the LB model for oil (octane) flow in quartz nanopores is also established by incorporating the MD simulation results. Oil flow simulation in quartz nanoporous media shows that the conclusions obtained for water flow are also applicable for oil flow.