Airslide flows. Part 2—Flow modeling and comparison with experiments
Airslide flows. Part 2—Flow modeling and comparison with experiments
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DOI：
10.1016/j.ces.2012.12.042
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发表时间：
2013-03
影响因子：
4.7
通讯作者：
L. Oger;S. Savage
中科院分区：
文献类型：
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作者：
L. Oger;S. Savage
这项研究是萨维奇和奥格（本期）回顾空气滑道实验研究的论文的续篇。这些设备利用流化作用来促进颗粒材料的长距离运输。本论文描述了一个详细的和全面的考虑的各种贡献的多相流方程和收益进行数值模拟的空气幻灯片流，并与实验室实验的结果进行比较。它部分使用开源多相流CFD程序MFIX进行。对MFIX分布版本中使用的控制方程进行了修订和补充。以前发表的分子动力学模拟的结果被用来制定一个修订的径向分布函数。准静态应力贡献的形式被设计成允许实验观察到的气滑流的典型的较高浓度流的发展。最后，在颗粒波动能量方程中包括附加项，以说明（i）由于间隙空气引起的波动颗粒的粘性耗散，以及（ii）从流体到颗粒的能量转移所产生的能量源项。这些表达式已被纳入计算方案和模拟的流化颗粒流在一个矩形通道有摩擦的侧壁进行。进行了一些初步的探索性计算，以检查各种参数对质量流率和速度分布的影响。不同的壁条件进行了研究，通过改变颗粒和壁恢复系数。还研究了改变最小流化速度和固体分数阈值的影响。然后，将模拟方案用于模拟两个有较好记录的流化槽流实验; Botterill和Bessant（1976）的实验，以及Liot（1979）和Chan（1979）的麦吉尔大学流化固体流道实验。这些计算结果和观察到的实验气滑行为的比较进行了讨论。数值模拟结果与实验结果吻合较好。
This study is a sequel to the paper of Savage and Oger ( this issue) that reviewed experimental studies of airslides. These devices make use of fluidization to facilitate the transport of granular materials over long distances. The present paper describes a detailed and comprehensive consideration of the various contributions to the governing multiphase flow equations and proceeds to carry out numerical simulations of airslide flows and compare the results with laboratory experiments. It was carried out in part using the open source multiphase flow CFD program MFIX. Revisions and additions to the governing equations used in the distribution version of MFIX were made. The results of previously published molecular dynamics simulations were used to formulate a revised radial distribution function. The forms of the quasi-static stress contributions were designed to permit the development of higher concentration flows typical of experimentally observed airslide flows. Finally, additional terms were included in the particle fluctuation energy equation to account for (i) the viscous dissipation of the fluctuating particles due to the interstitial air, and (ii) the energy source term arising from the transfer of energy from the fluid to the particles. These expressions have been incorporated in the computational scheme and simulations of fluidized granular flows in a rectangular channel having frictional side walls were carried out. Some initial exploratory calculations were performed to examine the effects of various parameters on the mass flow rates and the velocity profiles. Different wall conditions were studied by varying the particle and wall restitution coefficients. The effects of varying the minimum fluidization velocity and the solid fraction thresholds were also examined. The simulation scheme was then applied to model two of the better documented fluidized chute flow experiments; those of Botterill and Bessant (1976), and the McGill University fluidized solids flow channel experiments of Liot (1979) and Chan (1979). Results of these computations and comparisons with observed experimental airslide behavior are discussed. Good agreement is found between the simulations and the experimental airslide flow characteristics.