Boundary effects for Couette flow of granular materials: Dynamical modelling
Boundary effects for simple Couette flow of granular materials are examined using a dynamical modeling method. It is shown that the roughness of the boundary depends not only on the physical geometry of the boundary but also at least on the boundary speed and the particle fraction in the flow. Without consideration of the boundary speed, a geometrically rough boundary has no absolute meaning: a geometrically rough boundary can become smooth, and a smooth boundary can become rough. The relationship between the slip velocity and the boundary speed is found to be generally nonlinear and depending on the geometrical roughness and particle fraction. This investigation is important for industrial and engineering applications, such as the transportation and storage of the bulk materials.
scientific article; zbMATH DE number 880837
scientific article