Granular chute flow regimes: mass flowrates, flowrate limits and clogging

It has previously been shown that the transition from supercritical to subc ritical behavior in granular chute flows often results in the formation of stagnant zones which limit the mass flow and eventually clog the chute. Thi s paper reports an analysis of previously unpublished data for the flow of cohesionless granular material in inclined open channels. Three regimes of mass flow behavior, supercritical and two regimes of subcritical flow, were observed and are characterized by their dependence on chute inclination an d geometry. (This paper represents the first report of the third how regime .) Analysis of the experimental findings lead into empirical/mathematical e xpressions for the mass flow in the first two regimes as well as a predicti on of the regime transition points for all three regimes. This last gives i nsight into the effect of chute geometry on regime transition and the subse quent clogging of chutes.