Numerical measurement of flow fluctuations to quantify cohesion in granular materials, Physical Review E (2021)
When manipulating a powder, for example to pour it into another container or to mix it with another species, it is observed that all powders don’t flow in the same way. For example, granulated sugar flows much more smoothly than powdered sugar. This can be explained by the presence of long-range interactions between the particles that constitute these powders. In some cases, these particles can attract each other to form a cohesive granular material like powdered sugar.
We have developed numerical simulations that have allowed us to reproduce this particular flow of cohesive granular materials in the rotating drum. We have shown that agglomerates of grains flow at the grain-air interface and that the size of these aggregates is proportional to the cohesion intensity. A theoretical model of granular flow is adapted to take into account the effect of cohesion and to validate our observations.