Factors of the transition from dilute flow to dense flow in two-dimensional channel

Granular flow of steel beads from dilute flow to dense flow on an inclined two-dimensional channel is studied. The initial inflow Q(0) is always a dilute flow. A transition from dilute to dense is observed when D less than or equal to D-c. In the dense flow the outflow rate (Q) depends only on opening (D), given by Q = aD3/2. For different inflow rate Q(0) in the dilute flow case, the relation between the transition critical exit width (Dc) and the channel width (W) is given. And in larger inflow, the critical exit width is approximately in proportion to the square root of inflow rate, D-c proportional to Q(0)1/2.