Labyrinth weirs provide higher discharge capacity than conventional weirs, with the ability to pass large flows at comparatively low heads. Labyrinth weirs are primarily used as spillways for dams where the spillway w...Labyrinth weirs provide higher discharge capacity than conventional weirs, with the ability to pass large flows at comparatively low heads. Labyrinth weirs are primarily used as spillways for dams where the spillway width is restricted. In recent years, many research investigations have considered the hydraulic performance of labyrinth weirs, particularly as dependent on the geometric features. The previous work has improved the design basis for such weirs. However, their design still requires experimentally derived and generalized performance curves. It is especially important to observe the behavior of the weir nappe to ensure the design provides hydraulic optimization and to account for pressure fluctuations, possible vibrations, resonance effect, noise and flow surging. In the present study, discharge coefficients were experimentally determined for both circular labyrinth weirs and sharp crested trapezoidal labyrinth weirs of varying side wall angle (α). Additional studies were completed with nappe breakers included to reduce the impact of vibration on the labyrinth weirs. In general, the test data indicated that nappe breakers placed on the trapezoidal labyrinth weirs and circular labyrinth weirs reduced the discharge coefficient by up to 4% of the un-amended weir.展开更多
The labyrinth weir is a non-gate controlled discharge structure which has a broken-line overflow weir on surface to get longer length of overflow frontier,and has advantages of simple structure,larger discharge and co...The labyrinth weir is a non-gate controlled discharge structure which has a broken-line overflow weir on surface to get longer length of overflow frontier,and has advantages of simple structure,larger discharge and convenient operation,and so on.It's mainly used in spillway of medium and small reservoirs with advantage of improving the discharge capacity for both newly built spillway and reconstruction one.Based on the design of Anzihe reservoir,the paper preliminary explores the water flow regime,discharge capacity and hydraulic design of the labyrinth weir.The result of calculation and test is the discharge capacity of labyrinth is greater than the broad crest weir and practical weir under the same water head and more superiority under the lower water head.展开更多
文摘Labyrinth weirs provide higher discharge capacity than conventional weirs, with the ability to pass large flows at comparatively low heads. Labyrinth weirs are primarily used as spillways for dams where the spillway width is restricted. In recent years, many research investigations have considered the hydraulic performance of labyrinth weirs, particularly as dependent on the geometric features. The previous work has improved the design basis for such weirs. However, their design still requires experimentally derived and generalized performance curves. It is especially important to observe the behavior of the weir nappe to ensure the design provides hydraulic optimization and to account for pressure fluctuations, possible vibrations, resonance effect, noise and flow surging. In the present study, discharge coefficients were experimentally determined for both circular labyrinth weirs and sharp crested trapezoidal labyrinth weirs of varying side wall angle (α). Additional studies were completed with nappe breakers included to reduce the impact of vibration on the labyrinth weirs. In general, the test data indicated that nappe breakers placed on the trapezoidal labyrinth weirs and circular labyrinth weirs reduced the discharge coefficient by up to 4% of the un-amended weir.
文摘The labyrinth weir is a non-gate controlled discharge structure which has a broken-line overflow weir on surface to get longer length of overflow frontier,and has advantages of simple structure,larger discharge and convenient operation,and so on.It's mainly used in spillway of medium and small reservoirs with advantage of improving the discharge capacity for both newly built spillway and reconstruction one.Based on the design of Anzihe reservoir,the paper preliminary explores the water flow regime,discharge capacity and hydraulic design of the labyrinth weir.The result of calculation and test is the discharge capacity of labyrinth is greater than the broad crest weir and practical weir under the same water head and more superiority under the lower water head.
