Double-Ogee curve type bottom aeration facility for inhibiting cavity backwater

Abstract

The invention provides a double-Ogee curve type bottom aeration facility for inhibiting cavity backwater. The double-Ogee curve type bottom aeration facility for inhibiting the cavity backwater comprises an Ogee curve aeration ridge, an Ogee curve type backwater retaining plate, vent shafts, a vent channel and a vent window. The Ogee curve aeration ridge is connected with the straight line sectionof the upstream gentle slope of a release structure. One end of the Ogee curve type backwater retaining plate is connected with the bottom of the downstream end surface of the Ogee curve aeration ridge, the other end of the Ogee curve type backwater retaining plate is connected with the straight line section of the downstream steep slope of the release structure, the vent shafts are separately arranged on two sides of two walls of the release structure and close to the connecting position of the Ogee curve aeration ridge and the Ogee curve type backwater retaining plate, and the vent channelis arranged at the position, close to the downstream end of the Ogee curve aeration ridge, of the lower part of the bottom plate, penetrates through the release structure transversely and communicateswith the two vent shafts. The vent window is arranged on the downstream end surface of the Ogee curve aeration ridge and communicates with the vent channel, and the position, located on the downstream end surface of the Ogee curve aeration ridge, of the lower part of the vent window forms a water-retaining sill.

Description

technical field [0001] The invention belongs to the field of aeration facilities for drainage structures in water conservancy and hydropower projects, and particularly relates to an aeration facility for drainage structures with large single-width flow rate and low Fr number. Background technique [0002] With the development of water conservancy and hydropower engineering technology, large single-width flow (q>200m 2 / s) and low Froude number (Fr<3) drainage structures are increasing day by day. For such drainage structures, cavitation and cavitation damage are likely to occur on the flow side wall, so it is necessary to set up aeration facilities in the project to prevent Promote the aeration of water flow and prevent the occurrence of cavitation damage on the wall surface. [0003] Existing aeration facilities are usually aeration sills, but under the conditions of large single-width flow rate and low Fr number, the bottom aeration cavity behind the traditional aer...

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Problems solved by technology

[0004] In order to reduce the backwater in the cavity, the following technical measures are adopted in the prior art: 1) Increase the height of the aeration sill and the angle of the water flow, increase the length of the water flow, and extend the distance of the backwater to increase the cavity, but in order to avoid the water tongue The impact on the top of the discharge structure will inevitably require a larger flood discharge section, which will increase the radial size of the discharge structure and increase the investment, and the excessively high sill height will cause the impact force of the water tongue to drop to the downstream floor to be too high. 2) By adjusting the slope of the downstream floor, the angle of incidence between the water tongue and the downstream floor at the water drop can be reduced. However, in actual engineering, due to the relatively fixed elevation of the bottom plate and the limitation of geographical conditions, it is often impossible to make it too large. Adjust the slope of the downstream floor; 3) Adopt special-shaped air-entrained sills such as eight-shaped sills, U-shaped sills, V-shaped sills, and convex sills, but these sill types reduce the risk of cavity return water under the conditions of large single-width flow and low Fr number The effect is not ideal, and these hurdles may also disrupt the flow regime and cannot adapt to changes in flow

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