Experimental analysis of the orientation distribution of cylindrical particles with different aspect ratios in random packed beds

Abstract

This paper provides new experimental data on the orientation of cylindrical particles (defined as angle φ between the particle’s axis and the line parallel to the column axis) in random packed beds. In particular, the effect of particle’s aspect ratio is examined in detail. Three different values of particle’s aspect ratio in three columns with different diameters were examined. The research was also supplemented with numerical reconstructions of experimental cases in order to assess, among others, the capability of the numerical model to reproduce the orientation distribution for various aspect ratios. The effect of particles’ aspect ratio on particles’ orientation was found to be particularly evident in narrow columns where small values of φ become more favoured with increasing particles’ aspect ratio. In wider columns the effect is opposite as there is more significant contribution of higher angles. Also, the largest difference between loose and dense packing can be seen in narrow columns and is particularly manifested by a noticeable variation in probability of small orientation angles.