| High-speed flow problems has always restricted the development of flood discharge and energy dissipation in high dam.When we are faced with a high water head to flood discharge and energy dissipation,no matter what kind of single dissipation we would encounter some difficults to overcome hardly and considering its application condition is restricted to the deep-water gate.So we propose this new type of energy dissipator to solve these problems.This new type is made up of the jet energy dissipation phase and the horiXontal swirling flow.We will measure the hydraulic parameter such as flow velocity,pressure,length of water jum,cavity diameter,energy loss and so on.Then we could get the conclusions by analyXing experimental datas:1.The model is stably during its operation period when the water level of vertical shaft is higher than the water level of jet tailrace.2.The flow velocity and wall pressure in the spillway are different from each other in the upstream jet sections and downstream swirl sections, and the change of the jet orifice and the swirl flow is intense. Flow velocity distribution of swirl flow in swirl stage is approximately consistent with the distribution of quasi - free vortex..3.The amount of ventilation is affected by the change of the downstream water level,ventilation is larger when free flow in tail hole, and the ventilation volume is obviously reduced when the downstream outlet is submerged. However, with the increase of the downstream water level, ventilation is reduced slight.4.Through the jet section, consumed a part of the energy, thereby reducing the water head of the whirlpool section, making a high head energy dissipation problem into a mult i-level low head energy dissipation problem.The overall energy dissipation rate of this mo del test is 75% ~79% of the total head,where the first stage jet energy dissipation rate accounting for 15% of the total head to 22%, the second stage is 55 % to 62%. |
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