This study employed an experimental approach to investigate the effects of various filling degrees of the granular bed and the rotation speed on size-induced particle segregation behavior in an almost fully filled double-walled rotating drum. The distributions of the concentrations of bicolor particles in the system were obtained via image processing to determine the segregation state. The dynamics of the mixture flow including the statistical distribution, the azimuthal angle and radial direction granular temperature profiles were measured and calculated via particle-tracking velocimetry (PTV). The results were similar for the Brazil-nut effect and its reverse in the radial direction at high or low rotation speeds. When the rotation speed or filling degree was changed, the effect on two different particle sizes in the binary mixture system was inconsistent, and different flow mechanisms led to different segregation patterns. Two phase diagrams with the rotation speed and filling degree and the magnitude and position of the maximum granular temperature as the space enabled the prediction of segregation states.

本研究采用实验方法研究颗粒床的不同填充程度和转速对几乎完全填充的双壁转鼓中尺寸诱导的颗粒偏析行为的影响。通过图像处理获得系统中双色颗粒的浓度分布，以确定偏析状态。通过粒子跟踪测速仪（PTV）测量和计算混合物流的动力学，包括统计分布、方位角和径向颗粒温度分布。巴西坚果效应及其在高转速或低转速下的径向反向效应的结果相似。当转速或填充度发生变化时，二元混合物体系对两种不同粒径的影响是不一致的，不同的流动机制导致了不同的离析模式。以旋转速度和填充度以及最大颗粒温度的大小和位置为空间的两个相图可以预测偏析状态。