Abstract
Based on image processing, a novel method is presented for characterizing the flowability of cohesive powders undergoing the dynamic avalanching regime in a rotating drum. To benchmark the results, we compare them with the well-established flow of a non-cohesive sample and highlight quantitative differences between the two cases. As main result, we present the probability distribution and fluctuations of the average surface angle and the angle of stability. Cohesive powders display repeatable and reproducible data with considerably higher mean and average - different from the sample with glass beads.