Investigation of the Effect of Geometric Parameters on Head of the Morning Glory Spillway

Based on the water surface elevation, there is three types of flow control: flow control at the spillway crest, flow control at the shaft and flow control at the top of the shaft tunnel. In the following research, Flow3D software used for numerical modeling and the results were compared with experimental work, and good agreement was observed. Also, discharge - head graph is plotted for morning glory spillway, which shows by increasing the head, control point moves from the crest to the vertical shaft and then to downstream tunnel. In the case of complete submergence, significant changes in the head are observed with a low increase in flow rate. A parametric study has been done on the length of the vertical shaft and elbow radius. the results show the direct effect of these changes on head of the crest morning glory spillway, so that by increasing the length of the shaft, at a specified discharge increase head on crest, also by increasing the radius of the elbow, the head height on the crest reduced after the submergence elbow of morning glory spillway.