Energy Dissipation in Circular Drop Manholes under Different Outflow Conditions

摘要: Circular drop manholes have been an important device for energy dissipation and reduction of flow velocities in urban drainage networks. The a manhole depends on the patterns, outflow regimes exit pipe downstream operation conditions, is closely related to hydraulic geometric parameters manhole. In present work, with three heights was experimentally investigated under free conditions constrained conditions. results demonstrate that local head loss coefficient solely dimensionless parameter surface without backwater effect, whereas it submerge outflow. Moreover, concluded largely promoted when outlet choking occurs.