Unsteady Motion in Pipe Flow of Dense Gas-Solid Suspensions REU Supplement

叙述：在中低速的致密气固悬浮液中已观察到非定常分层运动，但缺乏预测手段。这个流量范围很重要，因为它对固体的加工和运输是节能的，因为它倾向于减少固体的磨损和设备的侵蚀。2英寸和5英寸管径的测试回路系统能够连续回收固体，因此在长时间的测试运行中，固体材料的投资最少。特别大的管道使详细的观察和测量成为可能。初步研究表明，可以直接观测到低速时的波动和相作用，并可与简单的波动分析进行比较。在中等速度和大颗粒密度下，基于探针电流或局部质量流自相关的频谱测量波浪运动是可行的。拟议的研究包括对基本配方和输运特性的进一步研究，以及对非定常水平管道流动范围的确定测量。自动相关性和相互相关性将在管道的不同位置，在一系列流动条件和颗粒上确定。目的是为了预测流动条件和扩大设计规模。

Narrative: Unsteady stratified motions have been observed in dense gas-solid suspensions at moderate and low velocities, but means for prediction are lacking. This flow range is significant because it is energy efficient for processing and transport of solids and because it tends to minimize attrition of solids and erosion of equipment. With test loop systems of 2-inch and 5-inch pipe diameters capable of continuous recycling of solids, a minimum investment of solid material is needed for prolonged test runs. The large pipe especially makes possible detailed observation and measurements. A preliminary study showed that wave motion and phase interactions at a low velocity can be directly observed, and comparison to simple wave analysis can be made. At moderate velocities and large particle densities, measurement of wave motion in terms of a spectrum based on autocorrelation of probe current or local mass flow was feasible. The proposed research includes further work on basic formulation and transport properties, and definitive measurements over a range of unsteady horizontal pipe flow at first. Both auto and cross- correlations will be determined at various positions in the pipe over a range of flow conditions and particles. The aim is toward prediciton of flow conditions and scale-up of designs.