Numerical investigation of aerator position effects on two-phase flow and hydraulic efficiency in morning glory spillway

Abstract This research examines the role of two-phase flow formation in crown control performance and orifice performance of Morning Glory spillways. The impact of an aerator was investigated through 3D simulations of the two-phase flow pattern within the Morning Glory spillway, focusing on optimal installation positions to mitigate negative pressure and prevent cavitation. ANSYS Fluent software was employed for the simulations. Results revealed significant negative pressures within the vertical shaft, with the aerator impacting only a small portion of this area. Geometric adjustments led to a reduction in negative pressures around the connection area, shifting them toward the beginning of the horizontal shaft. Additionally, these modifications resulted in a 50% decrease in negative pressures in the vertical shaft. The final design demonstrated an 81.6 and 50% decrease in cavitation index in the elbow and vertical shaft, respectively, compared to the initial design.