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过程工程学报 ›› 2018, Vol. 18 ›› Issue (6): 1187-1197.DOI: 10.12034/j.issn.1009-606X.218115

• 流动与传递 • 上一篇    下一篇

基于MP-PIC方法改进EMMS/DP曳力模型

王晓赞1,2, 姜 勇1,2, 李 飞1*, 王 维1,2   

  1. 1. 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 2. 中国科学院大学化工学院,北京 100049
  • 收稿日期:2018-01-15 修回日期:2018-03-29 出版日期:2018-12-22 发布日期:2018-12-19
  • 通讯作者: 李飞 lifei@ipe.ac.cn
  • 基金资助:
    国家重点研发计划;国家自然科学基金资助项目;国家自然科学基金资助项目

Improvement of EMMS/DP drag model based on MP-PIC method

Xiaozan WANG1,2, Yong JIANG1,2, Fei LI1*, Wei WANG1,2   

  1. 1. State Key Laboratory of Multiphase Complicated Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China 2. School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2018-01-15 Revised:2018-03-29 Online:2018-12-22 Published:2018-12-19
  • Supported by:
    ;The National Natural Science Foundation of China;The National Natural Science Foundation of China

摘要: 改进了面向离散粒子法的能量最小多尺度曳力模型(EMMS/DP)的颗粒参数生成方式,并将非均匀因子(HD)与固相浓度和滑移速度关联以考虑介尺度结构动态效应的影响,用改进的EMMS/DP模型与多相流质点网格模型(MP-PIC)耦合模拟气固两相流提升管系统,模拟结果与实验值吻合很好,考察了MP-PIC方法的网格无关性和粗粒化模型参数.

关键词: 关键词:EMMS/DP, MP-PIC, 非均匀曳力模型, 气固流态化, 数值模拟

Abstract: The energy minimization multi-scale drag model for discrete particle method (EMMS/DP) is a heterogeneous drag model applicable for discrete particle simulations. Particles distribute heterogeneously in circulating fluidized bed (CFB) flows due to clustering effect. Discrete particle method can provide detailded particle distributon information including particle position and particle velocity, but need assume evenly gas distribution inside computational cells. The inconsistence between particle field resolution and gas flow field resolution can lead to deviation between simulation result and actual measurement for heterogeneous gas?solid flows. To solve this problem, EMMS theory is applied to resolve the flow field around particles by accounting for the existence of particle clusters. Subsequently the heterogeneous drag force as well as the heterogeneous index (HD) are calculated based on the decomposed flow field to close the the interphase interaction terms in gas and particle momentum equations. Since the online calculation of EMMS/DP drag is very time consuming in real simulations, a predifined gas?solid flow field is applied to generate the HD database. The generated HD database can be used directly in discrete particle simulations thereafter, but will not increase computation load significantly. The current work improves the generating method of predifiend gas?solid flow field by taking consideration of the inhomogensou particles distributtion. In this work, HD was correlated with solid concentration and slip velocity based on the generated HD database to account for the dynamic effects of meso-scale structures. A comparison between HD at particle sacle and HD at computational cell scale was illustrated. The improved EMMS/DP drag model coupling with the multi-phase particles in cell (MP-PIC) method was used to simulate the gas?solid two phase flows in two CFB risers to verify the model. The simulation results were in good agreement with the experimental data. The grid-independence and effect of the coarse grained model parameter for MP-PIC on simulation results were also studied.

Key words: Key words: EMMS/DP, MP-PIC, heterogeneous drag model, gas-solid fluidization, numerical simulation