(398aa) Microscopic Models for the Prediction of Liquid Transfer in Granular Flows

Previous research in the area of wet granular flows mainly focused on forces connected to liquid bridges. However, there is much less theory concerned with the process of liquid transfer upon particle-particle and particle-wall collisions. To study the liquid transfer upon bridge formation and rupture, the Navier-Stokes equation can be simulated, i.e., direct numerical simulation (DNS) of the three-phase system can be performed. However, DNS of wet granular flow are extremely demanding, and also detailed experiments typically bring only a rather limited insight. Thus, currently available liquid transfer models are based on certain assumptions without rigorous validation.

Here we focus on a comparison of simulation results (using the discrete element method, DEM) for the dispersion of liquid in a range of dense to dilute granular flows. We use various liquid transfer models (e.g., the one proposed by Shi and McCarthy [1], or models developed by our group) in order to highlight key parameters that impact our simulation results. Specifically, we will present results for a simple shear flow, granular flow in a rotating drum (including an experimental validation study), as well as liquid transport in dense and dilute fluidized beds. Our results help in identifying the most appropriate microscopic liquid transfer model for those flow configurations.

References

[1]      D. Shi, J.J. McCarthy, Numerical simulation of liquid transfer between particles, Powder Technology. 184 (2008) 64–75.