Water-submerged granular flow through a long efflux tube

摘要

This paper presents an experimental investigation on the effect of a long efflux tube on water-submerged granular flow. A cylindrical bin connected to an outlet tube with length to diameter ratio of 100 at the bottom center was used to simulate the discharge processes. Pressure variations at the bin bottom and at the outlet were monitored with transducers. Effects of the tube on free water discharge, dry solid flow and solid and water mixture flow were investigated and compared. Experimental results found that significant negative pressure which can reach as large as the water pressure above the bin bottom was induced by the flow and the pressure gradient at the orifice had significantly increased the mass flow rate. A previously proposed equation with a corrected coefficient was used to fit the measured flow data and a quite well agreement was found.