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过程工程学报 ›› 2021, Vol. 21 ›› Issue (2): 125-133.DOI: 10.12034/j.issn.1009-606X.220323

• 流动与传递 • 上一篇    下一篇

运动颗粒对传质过程影响的格子Boltzmann模拟

贺睿1,乔崇智1,王利民2*,赵双良1*   

  1. 1. 华东理工大学化工学院，化学工程联合国家重点实验室，上海 200237 2. 中国科学院过程工程研究所多相复杂系统国家重点实验室，北京 100190
  • 收稿日期:2020-10-09 修回日期:2020-12-08 出版日期:2021-02-22 发布日期:2021-03-01
  • 通讯作者: 赵双良 szhao@ecust.edu.cn
  • 基金资助:
    国家重点研发计划资助项目;国家自然科学基金资助项目;中国科学院前沿科学研究重点计划;国家数值风洞工程;多相复杂系统国家重点实验室开放基金

Lattice Boltzmann simulation of mass transfer process affected by a moving particle

Rui HE1, Chongzhi QIAO1, Limin WANG2*, Shuangliang ZHAO1*   

  1. 1. State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China 2. State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2020-10-09 Revised:2020-12-08 Online:2021-02-22 Published:2021-03-01
  • Contact: Shuangliang Zhao szhao@ecust.edu.cn
  • Supported by:
    ;National Science Fund subsidized project

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摘要： 颗粒的主动运动对传质过程有重要影响。以表面恒浓度的二维球形颗粒为研究对象，采用耦合传质的格子Boltzmann方法(LBM)模拟了颗粒在自旋和振动两种情况下的相间传质过程。选择浸入运动边界法和非平衡态外推法处理运动颗粒边界，研究了颗粒自旋速度、颗粒振幅及振动频率对传质过程的影响。结果表明，中等雷诺数的自旋颗粒绕流中，随着颗粒自旋转速增大，颗粒的传质舍尔伍德数反而降低，表明在强制对流的情况下，颗粒自旋减弱颗粒的传质效果。当颗粒振动时，颗粒振幅越大，传质舍尔伍德数增大；当颗粒振动频率造成锁定现象时，颗粒流体相间传质效果显著增强。本工作的数值结果不仅表明格子Boltzmann方法可以有效模拟强制对流传质的过程，也为强化传质提供了一种思路。

关键词: 格子Boltzmann方法, 强制对流传质, 主动运动, 运动颗粒

Abstract: In the catalytic reaction system, the internal and external diffusion have a great impact on the total reaction rate through the influence on the mass transfer process. The internal diffusion in porous channels has been well investigated by statistical mechanics on the influence of wettability, roughness, and electric properties of channel walls. By contrast, the influence of external diffusion needs to be further studied such as, how the active motion of particles impacts the mass transfer. Herein, by using the lattice Boltzmann method coupled with mass transfer process, the influence of the forced rotation or vibration of the catalyst particle was studied. A circular particle with constant interfacial boundary concentration was considered, and the immersed moving boundary and non-equilibrium extrapolation methods were chosen to treat the liquid?particle interface. The effects of rotational speed, vibrational amplitude, and frequency on mass transfer were investigated. The simulations indicated that when only considering diffusion, particle rotation inhibited mass transfer. The higher the rotation speed, the worse the mass transfer, while the overall suppression effect was not significant. The particle streamwise vibration enhanced mass transfer significantly. The lock-on frequency was about 1.9, and the enhancement amplitude reached 10%. Increasing the amplitude and Reynolds number strengthened the mass transfer, and the lock-on frequency moved towards the low frequency direction, while the Schmidt number had little effect on the value of the lock-on frequency. The transverse vibration was also compared with the streamwise one and showed greater enhancement of Sherwood number at a lower frequency. This numerical results not only demonstrated the feasibility of the lattice Boltzmann method for simulating the forced convection mass transfer process but also provided a route for enhancing mass transfer.

Key words: lattice Boltzmann method, forced convection mass transfer, active motion, moving particle