Effect of Surface Topography on Particle Deposition from Liquid Suspensions in Channel Flow
Effect of Surface Topography on Particle Deposition from Liquid Suspensions in Channel Flow
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DOI：
10.3390/fluids5010008
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发表时间：
2020-01
期刊：
影响因子：
1.9
通讯作者：
M. Zaw;Liang Zhu;Ronghui Ma
中科院分区：
文献类型：
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作者：
M. Zaw;Liang Zhu;Ronghui Ma
建立了一个欧拉-拉格朗日模型来模拟低雷诺数下二维槽道流动中颗粒附着到具有弧形肋条的表面上。数值模拟的目的是为了提高对不同颗粒尺寸和流速下肋骨几何形状如何提高剪切速率和颗粒-表面相互作用的定量理解。增强的剪切速率归因于在肋形表面上发展的波状流动和相邻肋间形成的弱涡旋。改变螺距比可以改变波浪流的幅度和流体对肋骨的攻角。在这两个相互竞争的因素的存在下，节距与高度比为2的肋骨几何形状显示出最大的剪切速率和最低的颗粒附着比例。然而，在低速时，肋状表面对小颗粒的影响可以忽略不计。力分析确定了降低颗粒附着的阈值剪切速率。对于较大的颗粒，在较高的速度下，模拟的颗粒在肋形表面上的分布是高度不均匀的。了解表面形貌对颗粒附着的影响将有助于在广泛的应用中减少颗粒污垢的表面纹理的设计。
A Eulerian—Lagrangian model has been developed to simulate particle attachment to surfaces with arc-shaped ribs in a two-dimensional channel flow at low Reynolds numbers. Numerical simulation has been performed to improve the quantitative understanding of how rib geometries enhance shear rates and particle-surface interact for various particle sizes and flow velocities. The enhanced shear rate is attributed to the wavy flows that develop over the ribbed surface and the weak vortices that form between adjacent ribs. Varying pitch-to-height ratio can alter the amplitude of the wavy flow and the angle of attack of the fluid on the ribs. In the presence of these two competing factors, the rib geometry with a pitch-to-height ratio of two demonstrates the greatest shear rate and the lowest fraction of particle attachment. However, the ribbed surfaces have negligible effects on small particles at low velocities. A force analysis identifies a threshold shear rate to reduce particle attachment. The simulated particle distributions over the ribbed surfaces are highly non-uniform for larger particles at higher velocities. The understanding of the effect of surface topography on particle attachment will benefit the design of surface textures for mitigating particulate fouling in a wide range of applications.