矩形截面通道中颗粒惯性聚集现象的力学成因

The Mechanical Causes of Inertial Focus of Particles in Rectangular Section Channel

基于“相对运动模型”,利用CFD技术数值计算在矩形截面通道中刚性球形颗粒运动的力学特性,获得球形颗粒所受惯性升力的空间分布特征。分析使其稳定聚集位置产生变化的因素,为矩形截面通道中颗粒的惯性聚集现象的研究及可控性商业应用提供指导。研究结果表明:在矩形截面通道中,颗粒受到惯性升力水平分量的作用,远离短边壁面的中心附近向长边壁面方向移动,使本应存在的两个稳定聚集位置消失;流体雷诺数的不同会使颗粒所受的惯性升力竖直分量产生差异性变化,雷诺数较小时会使矩形截面通道中四个直角处的惯性聚集位置消失;截面通道高宽比会影响惯性升力水平分量的分布特征,颗粒的自转效应是这一现象的主要影响因素。

Based on the “Galileo Principle of Relativity”, a numerical model is proposed to describe the steady and constant motion of spherical particles, and the spatial distribution of the inertial lift of spherical particles in rectangular cross-section channel is studied by combining with CFD technology. The factors that cause the change of the stable aggregation position are analyzed, which can provide guidance for the study of the inertial aggregation of particles in rectangular cross-section channel and the controlled commercial application. The result of research shows that in the rectangular cross-section channel, the particles are affected by the horizontal component of the inertial lift, moving away from the center of the short side wall and towards the long side wall, so as to make the two stable aggregation positions that exist should disappear. Different Reynolds number of fluid will cause different changes in the vertical component of the inertial lift of particles. The ratio of height to width of the cross-section channel affects the distribution characteristics of horizontal components of inertial lift, and the rotation effect of particles is the main influencing factor of this phenomenon.