论文标题
通过气体从颗粒床释放的流体粒子悬浮液
Fluid-particle suspension by gas release from a granular bed
论文作者
论文摘要
我们研究了限制在Hele-Shaw细胞中的浸入颗粒层的底部的气体时，研究了颗粒悬浮液。这项工作的重点是颗粒的动力学比周围的流体略密集。以恒定流量率注入的气体通过颗粒床升起，然后形成气泡，这些气泡夹在上述液体层中。颗粒沉淀在细胞的边缘，在颗粒床不自由表面形成的火山口上的雪崩，并被中心的连续冒泡进一步夹住。我们报告了由于颗粒夹带和沉积之间的竞争而导致的固定状态的存在。悬浮液中的平均固体分数来自对颗粒床明显区域的简单测量。一个基于气泡在细胞中心及其侧面的气泡之间平衡的现象学模型表明，气泡夹带的大多数颗粒来自悬浮液的全局再循环。
We have studied experimentally particle suspension when injecting a gas at the bottom of an immersed granular layer confined in a Hele-Shaw cell. This work focuses on the dynamics of particles slightly denser than the surrounding fluid. The gas, injected at constant flow-rate, rises through the granular bed then forms bubbles which entrain particles in the above liquid layer. The particles settle down on the edges of the cell, avalanche on the crater formed at the granular bed free surface, and are further entrained by the continuous bubbling at the center. We report the existence of a stationary state, resulting from the competition between particle entrainment and sedimentation. The average solid fraction in the suspension is derived from a simple measurement of the granular bed apparent area. A phenomenological model based on the balance between particle lift by bubbles at the center of the cell and their settling on its sides demonstrates that most of the particles entrained by bubbles come from a global recirculation of the suspension.
