A two-phase flow model for submarine granular flows: With an application to collapse of deeply-submerged granular columns
A two-phase flow model for submarine granular flows: With an application to collapse of deeply-submerged granular columns
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DOI：
10.1016/j.advwatres.2017.12.012
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发表时间：
2018-05
影响因子：
4.7
通讯作者：
Cheng-Hsien Lee;Zhenhua Huang
中科院分区：
文献类型：
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作者：
Cheng-Hsien Lee;Zhenhua Huang
初始填料对浸没颗粒柱的坍塌过程有很大的影响。在基于流变学的两相流模型中，颗粒响应时间模型用于定量描述固液两相间的曳力，但在模拟不同初始浓度（初始填充条件）的颗粒柱坍塌过程时存在一定的困难。这项研究引入了一个新的模型的颗粒响应时间，这使我们能够令人满意地模拟两个阶段之间的拖曳力为广泛的体积浓度。该模型对松散堆积和密集堆积都能给出满意的结果。数值结果表明：（i）初始填充影响坍塌过程中收缩/扩张行为的发生;（ii）初始填充通过收缩和扩张强烈影响总浮力和总阻力;（iii）总浮力和总阻力在松散填充条件下使颗粒材料不稳定，但在密实填充条件下使颗粒材料稳定。结果表明，密排颗粒柱的坍塌过程对颗粒响应时间的敏感性高于散排颗粒柱。
The collapse process of a submerged granular column is strongly affected by its initial packing. Previous models for particle response time, which is used to quantify the drag force between the solid and liquid phases in rheology-based two-phase flow models, have difficulty in simulating the collapse process of granular columns with different initial concentrations (initial packing conditions). This study introduces a new model for particle response time, which enables us to satisfactorily model the drag force between the two phases for a wide range of volume concentration. The present model can give satisfactory results for both loose and dense packing conditions. The numerical results have shown that (i) the initial packing affects the occurrence of contractancy/diltancy behavior during the collapse process, (ii) the general buoyancy and drag force are strongly affected by the initial packing through contractancy and diltancy, and (iii) the general buoyancy and drag force can destabilize the granular material in loose packing condition but stabilize the granular material in dense packing condition. The results have shown that the collapse process of a densely-packed granular column is more sensitive to particle response time than that of a loosely-packed granular column.