On the significance of two-way coupling in simulation of turbulent particle agglomeration
On the significance of two-way coupling in simulation of turbulent particle agglomeration
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DOI：
10.1016/j.powtec.2017.05.027
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发表时间：
2017-08
影响因子：
5.2
通讯作者：
F. F. Dizaji-F.;J. Marshall
中科院分区：
文献类型：
--
作者：
F. F. Dizaji-F.;J. Marshall
研究报告，检查计算的湍流颗粒团聚与单向和双向相耦合的情况下，总颗粒浓度小。流体流动的计算使用直接数值计算，使用点力近似的颗粒诱导的体积力，和软球，粘性离散元方法被用来模拟颗粒的传输和团聚体的形成。计算进行了不同的值的斯托克斯数和粘附参数。采用多种测量手段研究了颗粒团聚对流体湍流度的影响以及颗粒团聚体内部的结构和流场。结果发现，团聚的影响不大的湍流衰减的颗粒，至少在斯托克斯数的范围内检查的文件。双向耦合的计算产生的团聚体更大，包含更多的颗粒比那些单向耦合。单向和双向耦合情况下的团聚体结构具有分形结构，具有相似的分形维数值。随着附聚物尺寸的增加，附聚物内的流体运动被发现变得越来越相关的附聚物的速度，作用于降低附聚物内的内部颗粒的相对速度和剪切应力。
A study is reported that examines computations of turbulent particle agglomeration with one-way and two-way phase coupling for cases with small overall particle concentration. The fluid flow was computed using a direct numerical computation using the point-force approximation for particle-induced body force, and a soft-sphere, adhesive discrete-element method was used to simulate the particulate transport and agglomerate formation. Computations were performed with different values of the Stokes number and the adhesion parameter. A variety of measures were used to examine both the effect of particle agglomeration on the fluid turbulence and the structure and flow field within the particle agglomerates. It was found that agglomeration has little influence on the attenuation of turbulence by the particles, at least in the range of Stokes numbers examined in the paper. Computations with two-way coupling generated agglomerates that were larger and contained more particles than those for one-way coupling. The agglomerate structure for both one-way and two-way coupling cases had a fractal structure with a similar value of the fractal dimension. As the agglomerate size increased, the fluid motion inside the agglomerates was found to become increasingly correlated to the agglomerate velocity, acting to decrease the relative velocity and shear stress of the inner particles within the agglomerate.