Packing fraction of clusters formed in free-falling granular streams based on flash x-ray radiography
Yuuya Nagaashi, Akiko M. Nakamura, Sunao Hasegawa, and Koji Wada
We study the packing fraction of clusters in free-falling streams of spherical and irregularly shaped particles using flash x-ray radiography. The estimated packing fraction of clusters is low enough to correspond to coordination numbers less than 6. Such coordination numbers in numerical simulations correspond to aggregates that collide and grow without bouncing. Moreover, the streams of irregular particles evolved faster and formed clusters of larger sizes with lower packing fraction. This result on granular streams suggests that particle shape has a significant effect on the agglomeration process of granular materials.