Three-dimensional numerical study on flow regimes of dry granular flows by DEM

Understanding the characteristics and mechanics of granular flows along sloping channels is fundamental and vital for the study of different in situ geophysical flows. Using the discrete element method (DEM), three-dimensional (3-D) dry granular flows are numerically modeled to study the contact behavior of solid particles along sloping channels, determine the 3-D velocity profiles along the flow height, and computer the corresponding shear rate. The channel confinement effect on granular flows is also investigated. By capturing the flow height and utilizing the definition of the Savage number, the variation in flow regimes inside a granular body along a sloping channel is researched. Finally, the fluctuation of solid particles in the flow is investigated with the use of granular temperature, and is proven to be influenced by the Savage number. Analysis shows that the combination of granular temperature and the Savage number is a good way to identify the flow regimes of granular flows.

Rheological characteristics of unsteady dry granular flows along a sloping channel are investigated by discrete element method in this paper. 3-D velocity profiles, the pertinent flow regimes, and then the fluctuation of solid particles in the flowing granular bodies are systematically studied, respectively.Figure optionsDownload as PowerPoint slideHighlights
► Unsteady channelized granular flows are simulated by discrete element method.
► Rheological characteristics of dry granular flows are investigated here.
► 3-D velocity profiles and the solids fluctuation in granular flows are researched.
► Flow regimes of channelized granular flows are identified.