Experimental Study on Water Diversion from Bottem with Porous Media

There are several methods for diverting discharge in rivers. Each of these methods has its own benefits and limitations. Gravity flow intake in rivers is possible in different ways; one of these ways is using pours media. The present research deals with an experimental model in Sari University of Agricultural Sciences and Natural Resources, doing 54 experiments to find out the effect of grain size of porous media, surface slope of pours media and different inflow on diverted discharge rate in bottom intake with porous media. The results show that discharge coefficient for horizontal intake surface at 11.9m3/s and grain size with D50 11.5 and 25 mm is equal to 0.053 and 0.068 respectively. It means discharge coefficient increases with increasing D50 of porous media‘s grain size. Also when flow rate is 11.9 m3/s and D50 equals to 11.5 mm, for two surface slope 0 and 20% the discharge coefficient is 0.053 and 0.039; that shows that increasing surface slope because decreasing discharge coefficient. Drawing the Intake diverted discharge coefficient changes vs inflow shows that discharge coefficient variation versus of inflow is higher at lower inflows but increasing inflow makes it stable. With analyzing the obtained data and using dimensional analysis and multiple regression on experiment results, an equation is proposed for estimating flow and discharge coefficient for this type of intake.