Yang C, Dabros T, Li D, Czarnecki J, Masliyah JH
Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, T6G 2G8, Canada
J Colloid Interface Sci. 1998 Dec 1;208(1):226-240. doi: 10.1006/jcis.1998.5806.
Based on the presented model for the impinging jet system, extensive theoretical analysis was made on particle deposition. Complete transport equations with consideration of gravity, van der Waals, and electrical double layer (EDL) interactions, as well as hydrodynamic interactions, were numerically solved. The influences of gravity, van der Waals, and electrical double layer interactions on the particle deposition rates (in terms of the Sherwood number) were presented. The results demonstrate that the asymmetric EDL interaction, which has been ignored in previous treatments, has an impact on the particle deposition rate. It was also found that the Sherwood number is strongly dependent on the characteristics of the particle-collector interaction energy profiles, such as the height of the energy barrier and the depth of the secondary energy minimum. Particularly, the effects of the height of the energy barrier and the depth of the secondary energy minimum on the Sherwood number for different Peclet numbers were discussed. In addition, a simple expression was derived for quantitatively estimating the contributions to the deposition rate due to particle diffusion, migration, and convection. With the aid of calculated particle concentration distributions, this expression can be used to understand the numerical predictions. Copyright 1998 Academic Press.
基于所提出的冲击射流系统模型,对颗粒沉积进行了广泛的理论分析。考虑重力、范德华力和双电层(EDL)相互作用以及流体动力学相互作用的完整输运方程通过数值求解得到。给出了重力、范德华力和双电层相互作用对颗粒沉积速率(以舍伍德数表示)的影响。结果表明,先前处理中忽略的不对称双电层相互作用对颗粒沉积速率有影响。还发现舍伍德数强烈依赖于颗粒 - 收集器相互作用能曲线的特征,例如能垒高度和二次能阱深度。特别讨论了能垒高度和二次能阱深度对不同佩克莱数下舍伍德数的影响。此外,还推导了一个简单表达式,用于定量估计颗粒扩散、迁移和对流对沉积速率的贡献。借助计算得到的颗粒浓度分布,该表达式可用于理解数值预测结果。版权所有1998年学术出版社。