底瑛棠, 赵兰浩, 毛佳. 颗粒沉降问题的高解析度CFD-DEM-IBM流固耦合数值模拟方法[J]. 水科学进展, 2021, 32(2): 286-294. DOI: 10.14042/j.cnki.32.1309.2021.02.014
引用本文: 底瑛棠, 赵兰浩, 毛佳. 颗粒沉降问题的高解析度CFD-DEM-IBM流固耦合数值模拟方法[J]. 水科学进展, 2021, 32(2): 286-294. DOI: 10.14042/j.cnki.32.1309.2021.02.014
DI Yingtang, ZHAO Lanhao, MAO Jia. A CFD-DEM-IBM method for sedimentation of particles with high resolution[J]. Advances in Water Science, 2021, 32(2): 286-294. DOI: 10.14042/j.cnki.32.1309.2021.02.014
Citation: DI Yingtang, ZHAO Lanhao, MAO Jia. A CFD-DEM-IBM method for sedimentation of particles with high resolution[J]. Advances in Water Science, 2021, 32(2): 286-294. DOI: 10.14042/j.cnki.32.1309.2021.02.014

颗粒沉降问题的高解析度CFD-DEM-IBM流固耦合数值模拟方法

A CFD-DEM-IBM method for sedimentation of particles with high resolution

  • 摘要: 为实现颗粒沉降问题的精确数值模拟,探索稠密颗粒两相流中流体与颗粒间的影响机制,基于浸入边界法(IBM),建立了高解析度CFD-DEM-IBM流固耦合数值模拟方法。分别通过流体动力学方法(CFD)及离散单元法(DEM)描述连续流体及非连续颗粒,引入浸入边界法处理颗粒移动边界,并在Navier-Stokes动量方程中附加体力项以体现流固相互作用,采用交错迭代算法在同一时间步内多次迭代求解直至收敛以实现流固间的强耦合。通过单、双、群颗粒的沉降行为模拟,结果表明:与传统CFD-DEM方法相比,该方法能够准确考虑颗粒间及流固两相间的相互作用,获得高解析度的流场信息。模拟结果与前人数值计算结果吻合,验证了该方法的准确性与有效性及其对稠密颗粒两相流问题的适用性与优越性。

     

    Abstract: A CFD-DEM-IBM method with high resolution is proposed based on the immersed boundary method (IBM) to describe the sedimentation phenomenon accurately and to investigate the underlying influence mechanism between fluid and particles in dense fluid-particle systems. The fluid phase is analyzed by the computational fluid dynamics (CFD) while the discrete element method (DEM) is utilized to simulate the motion of individual particles. The IBM is introduced to tackle the moving boundaries of particles and the interaction forces between fluid and particles are considered by an extra body force added to the Navier-Stokes momentum equation. The strongly coupled fluid-solid system is then achieved through the successive iterative scheme where several iterations are required within each time step until the convergence conditions are exactly satisfied. Sedimentations of one, two and multiple particles are simulated, which reveal that the proposed method could obtain the accurate interaction forces among discrete particles and fluid along with the fully resolved fluid phase around the particles compared with the conventional unresolved CFD-DEM method. The agreement between present results and previous work demonstrates the accuracy and validity of the presented method, and the applicability together with the superiority of the CFD-DEM-IBM method is also proved when the dense particulate flows occur.

     

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