Author(s): H. Von H"Afen; J. Stolle; N. Goseberg; I. Nistor
Keywords: Dam-break; Smoothed Particle Hydrodynamics; Swing gate; Lift gate; Bottom sill; Opening time
Abstract: This study investigates two gate devices which impound a volume of water, whose sudden release generates a dam-break wave. The aim is to identify the reciprocal interaction between the gate motion and the released volume of water. For the first time, lift gates and swing gates are systematically studied and compared. The influence by the opening of the gate on the evolving bore is related to the opening time. The overall objective of this study is to provide guidance as to how fast swing and lift gates need to open to effectively limit adverse effects on the formation of the dam-break wave. For this study, numerical simulations are conducted using the Smoothed Particle Hydrodynamics (SPH) formulation. The open source code DualSPHysics is used herein (Crespo et al., 2015). A calibrated setup is used to systematically investigate a large number of setups comprising constantlyaccelerated lift gates and swing gates opening with constant angular velocities. To match opening procedures of existing test facilities, the distance from the gate edges to the bottom of the flume is a quadratic function in time, anticipating electrically-or gravity-driven gate concepts. Based on the analysis of the time-history of the water surface elevation, a more detailed criterion for acceptable opening times for both, swing and lift gates is provided. A comparison with existing guidance on minimum opening times for lift gates is also provided; moreover, the updated opening criteria is valid for the entire section downstream of the gates. The use of the updated opening diagrams allows to determine minimum opening times for future experimentation.