非均匀颗粒流应力关系实验研究

颗粒流问题在自然界和许多工程领域都可能遇到。采用特殊的内外筒均可单独旋转的同心圆筒颗粒剪切实验装置，测量了非均匀离散颗粒在旋转剪切流动下的切应力变化，分析了颗粒浓度、粒径与边界条件等因素对颗粒流动应力的影响。结果表明，颗粒浓度和颗粒粒径均对剪切应力产生影响，Savage实验（内筒旋转）和Bagnold实验（外筒旋转）的结果产生差异的主要原因是边界滑移和旋转离心力。同时，基于已有成果，深入研究了颗粒应力关系变化的特点和规律。

Experimental studies of shear stress in granular flow with non-homogeneous solids

Granular flow should be found in many natural phenomena and engineering application. An experimental system was installed with two cylinders to investigate the shear stress in granular flow; both of the two cylinders could rotate respectively; and a series of experiments have been carried out including the shear stress in granular flow with non-homogeneous solids; especially, the parameters, solid concentration, solid diameter and boundary conditions, were measured and analyzed. The experimental results show that the solid concentration and the diameter have important effects on the shear stress of granular flow; the differences between experimental results by Savage (inner cylinder rotation )and Bagnold (outer cylinder rotation ) are due to the boundary slip and rotation eccentricity. On the bases of above experiments, the characteristics of the shear stress have been studied further.