Vani Nathan, Escudier Sacha, Sauret Alban
Department of Mechanical Engineering, University of California, Santa Barbara, California 93106, USA.
Soft Matter. 2022 Sep 21;18(36):6987-6997. doi: 10.1039/d2sm00962e.
Clogging can occur whenever a suspension of particles flows through a confined system. The formation of clogs is often correlated to a reduction in the cross-section of the channel. In this study, we consider the clogging by bridging, , through the formation of a stable arch of particles at a constriction that hinders the transport of particles downstream of the clog. To characterize the role of the volume fraction of the suspension on the clogging dynamics, we study the flow of particulate suspensions through 3D-printed millifluidic devices. We systematically characterize the bridging of non-Brownian particles in a quasi-bidimensional system in which we directly visualize and track the particles as they flow and form arches at a constriction. We report the conditions for clogging by bridging when varying the constriction width to particle diameter ratio for different concentrations of the particles in suspension. We then discuss our results using a stochastic model to rationalize the influence of solid fraction on the probability of clogging. Understanding the mechanisms and conditions of clog formation is an important step for optimizing engineering design and developing more reliable dispensing systems.
每当颗粒悬浮液流经受限系统时，都可能发生堵塞。堵塞的形成通常与通道横截面的减小有关。在本研究中，我们考虑通过在障碍物处形成稳定的颗粒拱来实现架桥堵塞，这种堵塞会阻碍颗粒在堵塞下游的传输。为了表征悬浮液体积分数对堵塞动力学的作用，我们研究了颗粒悬浮液通过3D打印微流体装置的流动情况。我们系统地表征了准二维系统中非布朗颗粒的架桥情况，在该系统中，我们直接可视化并跟踪颗粒在流动过程中以及在障碍物处形成拱的过程。我们报告了在悬浮液中颗粒浓度不同时，改变障碍物宽度与颗粒直径之比时通过架桥发生堵塞的条件。然后，我们使用随机模型讨论我们的结果，以合理化固体分数对堵塞概率的影响。了解堵塞形成的机制和条件是优化工程设计和开发更可靠的分配系统的重要一步。
