Effect of number of raised ladder on the hydraulic characteristics of integrated energy dissipator
CHEN Weixing1, YANG Jurui1*, DONG Liyan1, WU Ouyu2, LI Shuzhao3
1. Faculty of Modern Agricultural Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650500, China; 2. Faculty of Architectural Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650500, China; 3. Dongguan Water Resources Survey and Design Institute Co., Ltd., Dongguan, Guangdong 523000, China
The transitional ladder has a certain influence on the integrated energy dissipation mode of flaring gate piers, stepped spillways and stilling basins, and raised ladder is particularly important for this effect. The study presents a numerical simulation on the 5-hole transitional ladder design for the spillway of Ahai hydropower station. With an aerator height of 1m at an angle of 10? for the flaring gate piers combined with stepped spillway and stilling basin, the hydraulic model test was carried out for the four kinds of transition steps with the number of raised ladder 0, 1, 2, 3 respectively. Various hydraulic characteristics such as the surface line of the stilling pool, the near-bottom flow velocity, the negative pressure, the time-averaged pressure and the energy dissipation rate were studied.The study found that: The near-bottom flow velocity decreases with the increase of the volume of the aerated ca-vity, and increases with the decrease of the number of stepped protrusions. Under the interaction of the two, the flow velocity of each solution reaches the minimum at the end of the stilling pool, the flow velocity of model 2 is the smallest, 22.23 m/s; Owing to the collective effect between the volume of the aerated cavity with the number of raised ladder, the negative pressure of model 2 is the smallest, reaching -33.66 kPa; The energy-dissipating rates of models 1, 2, 3 and 4 are in turn 59.56%, 61.06%, 60.37% and 59.99%, respectively. The energy dissipation rate of model 2 is the highest.
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