阅读说明：本技术 一种能增强水流表面自掺气能力的压坡上缘 (Slope upper edge capable of enhancing self-aeration capacity of water flow surface ) 是由 补金梓 王文杰 邓书山 李�浩 于 2021-08-09 设计创作，主要内容包括：本发明公开了一种能增强水流表面自掺气能力的压坡上缘,属于水利水电工程掺气减蚀技术领域。所述压坡上缘上沿压坡纵向设有凹槽,所述凹槽的底面为一倾斜面,底面的一端与压坡出口相交,另一端与压坡上缘的顶面相交,所述凹槽的两侧面均为光滑曲面,所述凹槽的横截面形状呈U形。提出了一种全新概念的掺气方式,通过改变水流表面的形状来增大水流表面卷吸空气的能力,它颠覆了以往对过流壁面实现掺气保护只能通过改变侧壁或者底板形状形成掺气空腔的思维,提出了一种实现掺气保护的全新设计思路,且其结构简单,易于实施,可在各种水利工程中广泛应用。(The invention discloses a pressure slope upper edge capable of enhancing the self-aeration capacity of a water flow surface, and belongs to the technical field of aeration corrosion reduction of water conservancy and hydropower engineering. The upper edge of the pressure slope is longitudinally provided with a groove along the pressure slope, the bottom surface of the groove is an inclined surface, one end of the bottom surface is intersected with the outlet of the pressure slope, the other end of the bottom surface is intersected with the top surface of the upper edge of the pressure slope, the two side surfaces of the groove are smooth curved surfaces, and the cross section of the groove is U-shaped. The novel aeration method has the advantages that the aeration mode with a brand-new concept is provided, the air entrainment capacity of the water flow surface is improved by changing the shape of the water flow surface, the thinking that the aeration protection of the overflow wall surface can be realized only by changing the shape of the side wall or the bottom plate to form an aeration cavity in the prior art is subverted, the novel design idea for realizing the aeration protection is provided, the structure is simple, the implementation is easy, and the novel aeration method can be widely applied to various hydraulic engineering.)

1. A kind of slope upper edge that can strengthen the surface of the waterflow and self-aerating ability, characterized by that: the upper edge of the pressure slope is longitudinally provided with a groove along the pressure slope, the bottom surface of the groove is an inclined surface, one end of the bottom surface is intersected with the outlet of the pressure slope, the other end of the bottom surface is intersected with the top surface of the upper edge of the pressure slope, the two side surfaces of the groove are smooth curved surfaces, and the cross section of the groove is U-shaped.

2. The uphill edge of claim 1, capable of enhancing self-aeration of a water flow surface, wherein: the length of the groove is L (0.4-0.7) L₀，L₀Is the length of the pressure slope.

3. The uphill edge of claim 1, capable of enhancing self-aeration of a water flow surface, wherein: the bottom surface of the groove is rectangular, the width of the bottom surface is B (0.4-0.7), and B is the width of the slope pressing outlet.

4. The uphill edge of claim 3, wherein the uphill edge is capable of enhancing self-aeration of a water flow surface, and the uphill edge is characterized in that: the bottom surface of the groove is symmetrically arranged relative to the longitudinal section of the central line of the upper edge of the overpressure slope.

5. The uphill edge of claim 1, capable of enhancing self-aeration of a water flow surface, wherein: the depth of the slope pressing outlet end of the groove is h (0.1-0.3) h₀，h₀Is the original height of the slope pressing outlet.

6. The uphill edge of claim 1, capable of enhancing self-aeration of a water flow surface, wherein: the two side surfaces of the groove are symmetrical, and the symmetrical surface is a longitudinal section of the central line of the upper edge of the overpressure slope.

7. The uphill edge of claim 1, capable of enhancing self-aeration of a water flow surface, wherein: the shape of the smooth curved surface is gradually reduced from the slope pressing outlet end to the other end, and the size is also gradually reduced to zero from the slope pressing outlet end to the other end.

8. The uphill edge of claim 7, capable of enhancing self-aeration of a water flow surface, wherein: the horizontal width of one end, close to the slope pressing outlet, of the smooth curved surface is a (0.15-0.3) B.

Technical Field

The invention relates to a pressure slope upper edge capable of enhancing the self-aeration capacity of a water flow surface, and belongs to the technical field of aeration corrosion reduction of water conservancy and hydropower engineering.

Background

In the flood discharge process, because a large amount of concentrated energy (potential energy) is released through a relatively small-sized water discharge structure, certain influence is inevitably caused on the structural stability and safety of the overflowing wall surface of the water discharge channel, when the energy is overlarge, the water discharge structure can be damaged, and except that reasonable treatment is carried out on structural flatness, structural strength and body type as far as possible, an aeration facility with a certain size is often arranged along the way of the water discharge structure in engineering to carry out aeration treatment on high-speed water flow, so that aeration protection is formed on the overflowing wall surface. Aeration facilities such as an aeration bucket, an aeration tank, a free combination of the aeration bucket and the aeration tank are usually adopted to carry out forced aeration on the water flow.

Chinese patent publication No. CN205421200U discloses an outlet trajectory energy dissipation structure of an outlet of a water outlet structure, which includes a trajectory structure composed of a trajectory structure bottom plate and trajectory structure side walls, wherein an outlet end of the trajectory structure bottom plate is warped upwards, the trajectory structure side walls are disposed at two sides of the trajectory structure bottom plate, and further includes groove-shaped notch trajectory steep grooves disposed at an outlet end of the trajectory structure bottom plate and extending to an outlet of the trajectory structure. The novel trajectory jet energy dissipation structure greatly increases the longitudinal diffusion degree of water flow, and reduces the water inlet amount per unit area through air diffusion and collision, thereby reducing the scouring capacity of trajectory jet tongues on downstream riverbeds.

The trajectory energy dissipation structure is connected with a river bed and is mainly used for reducing the scouring effect of a nappe on the river bed, the slope is generally connected with open-flow water drainage structures such as a flood discharge hole with the inner width being the same as the width of a slope outlet, and if the trajectory energy dissipation structure is applied to the slope, the top and the overflowing wall surface of the flood discharge hole can be subjected to strong impact, and the aim of aeration protection cannot be achieved.

Disclosure of Invention

In order to solve the technical problem, the invention provides the pressure slope upper edge capable of enhancing the self-aeration capacity of the water flow surface.

The invention is realized by the following technical scheme:

the pressure slope upper edge is provided with a groove along the pressure slope in the longitudinal direction, the bottom surface of the groove is an inclined surface, one end of the bottom surface is intersected with a pressure slope outlet, the other end of the bottom surface is intersected with the top surface of the pressure slope upper edge, two side surfaces of the groove are smooth curved surfaces, and the cross section of the groove is U-shaped.

The length of the groove is L (0.4-0.7) L₀，L₀Is the length of the pressure slope.

The bottom surface of the groove is rectangular, the width of the bottom surface is B (0.4-0.7), and B is the width of the slope pressing outlet.

The bottom surface of the groove is symmetrically arranged relative to the longitudinal section of the central line of the upper edge of the overpressure slope.

The depth of the slope pressing outlet end of the groove is h (0.1-0.3) h₀，h₀Is the original height of the slope pressing outlet.

The two side surfaces of the groove are symmetrical, and the symmetrical surface is a longitudinal section of the central line of the upper edge of the overpressure slope.

The shape of the smooth curved surface is gradually reduced from the slope pressing outlet end to the other end, and the size is also gradually reduced to zero from the slope pressing outlet end to the other end.

The horizontal width of one end, close to the slope pressing outlet, of the smooth curved surface is a (0.15-0.3) B.

The invention has the beneficial effects that: the novel aeration method has the advantages that the aeration mode with a brand-new concept is provided, the air entrainment capacity of the water flow surface is improved by changing the shape of the water flow surface, the thinking that the aeration protection of the overflow wall surface can be realized only by changing the shape of the side wall or the bottom plate to form an aeration cavity in the prior art is subverted, the novel design idea for realizing the aeration protection is provided, the structure is simple, the implementation is easy, and the novel aeration method can be widely applied to various hydraulic engineering.

Drawings

FIG. 1 is a schematic perspective view of the present invention;

FIG. 2 is a schematic top view of the present invention;

fig. 3 is a left side view of the structure of fig. 2.

Detailed Description

The technical solution of the present invention is further described below, but the scope of the claimed invention is not limited to the described.

As shown in fig. 1 to 3, the upper edge of the pressure slope capable of enhancing the self-aeration capability of the water flow surface according to the present invention is provided with a groove along the longitudinal direction of the pressure slope, the bottom surface of the groove is an inclined surface, one end of the bottom surface is intersected with the outlet of the pressure slope, the other end is intersected with the top surface of the upper edge of the pressure slope, both side surfaces of the groove are smooth curved surfaces, and the cross section of the groove is U-shaped. When the device is used, the grooves are sunken downwards and extruded towards two sides, so that water flow passing through the slope pressing outlet is in a wide U shape, then a rapid shock wave which forms a certain angle with the wall surface of the overflowing vertical wall is formed under the free diffusion effect of the water flow, the shock waves at two sides are crossed in the middle of the discharge groove and then continuously spread along respective original directions, a rhombic wave similar to that generated by narrow outflow boundary beams when the conventional spillway is opened and discharged is formed, the air self-entrainment capacity of the surface of the water flow is greatly enhanced, and the water flow gradually develops to the wall surface to form aeration protection.

The length of the groove is L (0.4-0.7) L₀，L₀Is the length of the pressure slope. Generally, the larger the L, the smoother the water flow transition, but the larger the L, the greater the construction difficulty and the engineering investment.

The bottom surface of the groove is rectangular, the width of the bottom surface is B (0.4-0.7), and B is the width of the slope pressing outlet. b is too small, the diffusion included angle of water flow at two sides is relatively small, the formed rhombic shock wave is long and narrow in shape, the shock wave transmission path is short, and the aeration is not facilitated; if b is too large, the flow capacity of the slope outlet is greatly influenced, and meanwhile, the diffusion effect of the water is weakened due to the fact that the water flow of the bulges at the two sides of the groove is reduced, and efficient surface aeration cannot be formed.

The bottom surface of the groove is symmetrically arranged relative to the longitudinal section of the central line of the upper edge of the overpressure slope. To ensure that the shock wave generated by the outflow water surface propagates along the way symmetrically.

The depth of the slope pressing outlet end of the groove is h (0.1-0.3) h₀，h₀Is the original height of the slope pressing outlet. The smaller the h value is, the smaller the height difference of the surface of the emergent water flow is, which is not beneficial to the entrainment of gas; and if the value h is too large, the flow discharge capacity of the slope pressing outlet is obviously influenced.

The two side surfaces of the groove are symmetrical, and the symmetrical surface is a longitudinal section of the central line of the upper edge of the overpressure slope.

The shape of the smooth curved surface is gradually reduced from the slope pressing outlet end to the other end, and the size is also gradually reduced to zero from the slope pressing outlet end to the other end. The outflow water surface deflects through the smooth curved surface to suck gas, so that the aeration effect is greatly improved.

The horizontal width of one end, close to the slope pressing outlet, of the smooth curved surface is a (0.15-0.3) B. In order to avoid the phenomenon that the grooves are suddenly sunken to cause water flow to be separated from the wall surface between the grooves, thereby causing cavitation damage, two side surfaces of each groove are designed into smooth curved surfaces.

The water flow is often forced to be aerated by adopting aeration facilities such as an aeration bucket, an aeration tank, a free combination of the aeration bucket and the aeration tank, the forced aeration is generally effective only in a certain range, and after a water tongue collision point, the aeration concentration can be quickly attenuated, so that a plurality of aeration facilities need to be arranged. Therefore, compared with forced aeration, the invention has the advantages that the structure of the upper edge of the pressure slope is completely new designed to achieve the purpose of protecting the overflowing wall surface by water flow self-aeration, the aeration concentration attenuation speed is low, and the engineering investment is relatively low.

The invention provides a pressure slope upper edge capable of enhancing the self-aeration capacity of a water flow surface, which has the following beneficial effects: the novel aeration method has the advantages that the aeration mode with a brand-new concept is provided, the air entrainment capacity of the water flow surface is improved by changing the shape of the water flow surface, the thinking that the aeration protection of the overflow wall surface can be realized only by changing the shape of the side wall or the bottom plate to form an aeration cavity in the prior art is subverted, the novel design idea for realizing the aeration protection is provided, the structure is simple, the implementation is easy, and the novel aeration method can be widely applied to various hydraulic engineering.