Transportation and accumulation processes of particles in fluid flows with DEM

DEM 流体流动中颗粒的传输和积累过程

• 批准号: 15560443
• 负责人: USHIJIMA Satoru
• 金额: $ 2.43万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15560443/
• 关键词: three-phase flow; incompressible flow; particle transportation; critical condition for particle movement; free-surface flow; fluid force; distinct element method

A computational method has been developed to predict the transportation of large-scale solid bodies due to 3D free-surface flows. The MICS is based on the CFD method for incompressible flows, in which the treatment for density and mass conservation has been improved in the collocated grid. The multiphase field including solid bodies and liquid and gas phases separated by free surfaces is assumed to be consist of the incompressible and immiscible fluids with different physical properties. The discretization of pressure equations was examined to obtain the numerically stable converged results. The external forces for the particles are evaluated from the results of the fluid computations and a model of the distinct element method(DEM).It was shown that the particle drag coefficients and wake flows are successfully predicted with MICS. The MICS was applied to a falling particle near a side wall and non-uniform particles moving on the inclined bottom surface. As a result, it was demonstrated that MICS is effective to predict the particle-laden flows. Furthermore, it was shown that the numerical method enables us to predict Rayleigh-Taylor stability problem and drag coefficient of a sphere in a uniform flow as well as the results of hydraulic experiments related to the transportation of multiple spheres by the flow accompanied by wave motions.

发展了一种计算方法来预测三维自由表面流动引起的大尺度固体的输运。MICS基于不可压缩流动的CFD方法，改进了配置网格中密度守恒和质量守恒的处理方法。假设多相场由具有不同物理性质的不可压缩流体和不可混溶流体组成，包括固体和自由表面分离的液、气两相。研究了压力方程的离散化，得到了数值稳定的收敛结果。根据流体计算的结果和离散单元法(DEM)的模型计算了颗粒的外力，结果表明，MICS方法成功地预测了颗粒的阻力系数和尾流。MICS被应用于侧壁附近的下落颗粒和倾斜底面上运动的非均匀颗粒。结果表明，MICS模型对颗粒流动的预测是有效的。数值计算结果表明，该数值方法能较好地预测均匀流中球体的Rayleigh-Taylor稳定性问题和阻力系数，以及与波浪伴生的流动中多个球体输运有关的水力学试验结果。

项目成果

漸縮・漸拡部と分岐を有するダクト内の沈降性物質輸送の数値計算

逐渐收缩和扩张部分和分支的管道中沉积物质量传输的数值计算

• 发表时间: 2005
• 期刊: 水工学論文集 第49巻
• 作者: 円界正憲;牛島 省;小久保鉄也;大本雄二;禰津 家久
• 通讯作者: 禰津 家久

Turbulence modification in vertical jets laden with slow large particles

载有缓慢大颗粒的垂直射流的湍流修正

• 发表时间: 2003
• 期刊: Transactions of the JSME No.679
• 作者: S.Ushijima;N.Hase;I.Nezu
• 通讯作者: I.Nezu

多相流体に対する統一的解法に基づく移動物体周辺の非圧縮性流体の数値解析法

基于多相流体统一求解方法的运动物体周围不可压缩流体数值分析方法

• 发表时间: 2003
• 期刊: 応用力学論文集 vol.6
• 作者: 牛島 省;竹村 雅樹;山田 修三;禰津 家久
• 通讯作者: 禰津 家久

牛島 省, 竹村 雅樹, 山田 修三, 禰津 家久: "流体力評価制度の高いDEMの提案と底質粒子初期移動過程への適用"海岸工学論文集. 第50巻. 506-510 (2003)

Sho Ushijima、Masaki Takemura、Shuzo Yamada、Iehisa Nezu：“具有高流体力评估系统的 DEM 的提议及其在沉积物颗粒初始运动过程中的应用”海岸工程论文第 50 卷。506-510 (2003)。

牛島 省(共著): "並列計算法入門"丸善株式会社. 135 (2003)

Sho Ushijima（合著者）：《并行计算方法导论》Maruzen Co., Ltd. 135（2003）