Granular Shear Instabilities: Oscillations, Waves and Rolls?

abstractcts - 0070591 t。本文旨在研究两种粒子流快速流过分流板时的流动微观结构和不稳定性。这是一个简单的流动几何，可以研究基本方面，如不稳定性的类型，典型的速度和涡度流动结构，流之间的界面形状，控制过渡的无因次数，以及颗粒间粘滑现象对不稳定性的作用。这项研究是由一项小规模实验的观察结果引发的，该实验发现了开尔文-亥姆霍兹型不稳定性的意外迹象。主要实验是基于准二维流的流动可视化，在两个颗粒流的汇合处使用彩色和示踪粒子。颗粒大小对各种剪切流模式的影响，包括大涡和滚子中颗粒运动的集体行为，将通过实验确定。本探索性研究旨在建立一个相对简单的剪切流的流动模式，并得出从微米到纳米大小的不同粒径颗粒体系的基本流动机制。如果成功，这个概念验证项目可能会应用于混合，化学和制药加工工业，聚合物和陶瓷加工。

AbstractCTS-0070591T. Shinbrot and B.J. Glasser, Rutgers University - New BrunswickIt is proposed to investigate the flow microstructure and instabilities in rapid flow of two particle streams past a splitter plate. This is a simple flow geometry where fundamental aspects can be studied, such as the type of instability, typical velocity and vorticity flow structures, the shape of the interface among streams, dimensionless numbers governing the transition, and the role of interparticle stick-slip phenomenon on instabilities. The research was triggered by observations made on a small-scale experiment where unexpected indications of Kelvin-Helmholtz type instabilities have been noticed. The main experiment is based on flow visualization of a quasi-two-dimensional flow using colored and tracer particles at the confluence of two particulate streams. The effect of particle size on various shear flow patterns, including collective behavior of particle motion in large vortices and rollers, will be experimentally determined. This exploratory research aims to establish the flow pattern in a relatively simple shear flow and to derive conclusions for the basic flow mechanisms in particle systems of various particle sizes from micron to nanosize.If successful, this proof of concept projects may have applications in mixing, in chemical and pharmaceutical processing industry, in polymer and ceramics processing.