Narrow slit outlet flip bucket with non-aligned bottom plate and side wall

Abstract

The narrow slit outlet flip bucket comprises the first side wall, the second side wall, the third side wall, the fourth side wall and the bottom plate, the first side wall and the second side wall are arranged on the two sides of the bottom plate in parallel, the first side wall is connected with the third side wall, the second side wall is connected with the fourth side wall, and the bottom plate is connected with the third side wall. The width between the third side wall and the fourth side wall is gradually reduced in the water flow direction, the third side wall and the fourth side wall are not flush with the bottom plate, and three forms that the bottom plate is not flush with the single side wall and the bottom plate is not flush with the single side wall exist. According to the flip bucket, a nappe can be fully diffused in the longitudinal direction, meanwhile, the flowing position of water in the bucket is changed in the mode that the bottom plate is not flush with the side wall, then the falling point of the nappe is changed, the nappe is guided, and therefore the safety and stability of a bank slope are guaranteed, and the shape can be changed according to different engineering conditions to meet different energy dissipation requirements.

Description

Technical Field

[0001] This invention relates to the field of energy dissipation sill technology, specifically to a narrow-slit outlet sill where the base plate and sidewall are not aligned. Background Technology

[0002] In hydraulic and hydropower projects, the water discharged through spillway structures often has extremely high velocities and carries enormous energy, posing a significant destructive potential to downstream riverbeds and even the main structures. To ensure the safety of the structures and downstream river channels, engineering practices typically follow the principle of maximizing the effective water inlet area through dispersed water flow, thereby dispersing energy. Narrow-slot sills are a common energy dissipation structure that longitudinally diffuses the water jet. Common shapes of narrow-slot sills are shown in [reference needed]. Figure 1 .

[0003] Using a narrow-slit sill can increase the longitudinal distance between the water inflow points. In narrower river valleys, the water jet can impact the bank slope, affecting its safety and stability. This often necessitates altering the sill outlet location, creating a non-centrally symmetrical narrow-slit sill, directing the water flow away from the bank slope. In this case, the sill's shape becomes... Figure 2 .

[0004] Due to the uneven contraction of the sidewalls, the non-centrally symmetrical narrow-slit sills, under the influence of the deflecting water flow, cause the water flow to constantly turn between the sidewalls and release into the air at the outlet, generating a huge spalling flow that erodes the bank slope and affects its safety and stability. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of conventional narrow-slit weirs as described above, and to make it easier for narrow-slit weirs to change the water jet entry shape, thereby protecting the safety and stability of the riverbed and bank slopes.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: The narrow slit outlet with a non-aligned base plate and sidewalls includes a first sidewall, a second sidewall, a third sidewall, a fourth sidewall, and a base plate. The first and second sidewalls are arranged parallel to each other on both sides of the base plate. The first sidewall connects to the third sidewall, and the second sidewall connects to the fourth sidewall. The width between the third and fourth sidewalls gradually decreases along the water flow direction. The ends of the third and fourth sidewalls are not aligned with the base plate.

[0007] As a preferred technical solution, the third sidewall 3 contracts inward, and the slope of the contraction of the third sidewall satisfies: i1=b1 / L1, where i1 is the slope of the contraction of the third sidewall, L1 is the longitudinal distance from the end of the third sidewall to the end of the first sidewall, and b1 is the lateral distance from the end of the third sidewall to the end of the first sidewall.

[0008] As a preferred technical solution, the fourth side wall 4 contracts inward, and the slope of the fourth side wall contraction satisfies: i2=b2 / L2, where i2 is the slope of the fourth side wall contraction, L2 is the longitudinal distance from the end of the fourth side wall to the end of the second side wall, and b2 is the lateral distance from the end of the fourth side wall to the end of the second side wall.

[0009] As a preferred technical solution, the shrinkage slopes of the third and fourth side walls satisfy the following: the shrinkage slopes i1 and i2 of the third and fourth side walls are both greater than or equal to 0 and less than or equal to 1 / 20.

[0010] As a preferred technical solution, the included angle between the end of the base plate and the central axis satisfies: α = 15°-90°, where α is the included angle between the base plate and the central axis.

[0011] As a preferred technical solution, the width of the end of the base plate satisfies: b3=(0.2-0.5)B, where b3 is the width of the end of the base plate and B is the distance between the first side wall and the second side wall.

[0012] As a preferred technical solution, the longitudinal distance from the midpoint of the end of the base plate to the end of the first and second side walls is L3.

[0013] As a preferred technical solution, the base plate is one of a circular arc surface, a horizontal surface, and a sloped surface.

[0014] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: The cantilever sill described in this invention allows for full longitudinal diffusion of the water jet while controlling the water flow release point by changing the position of the end of the sidewall or the end of the bottom plate, thereby altering the landing point of the water jet. Changing the position of the bottom plate end changes the starting position of the water flow leaving the cantilever sill, thus changing the landing point of the water jet at the lower edge. Simultaneously, the longitudinal stretching effect of the water jet is further amplified by the contraction of the sidewall. Changing the position of the sidewall end changes the position of the lateral diffusion of the water flow, enhancing the lateral deflection of the water jet and reducing the water jet fragmentation phenomenon caused by forced deflection, thereby ensuring the safety and stability of the bank slope. This invention allows for free adjustment of the ending positions of the bottom plate and sidewall of the narrow-slit cantilever sill according to actual engineering conditions, making it suitable for flood discharge and energy dissipation needs under different terrain conditions. Attached Figure Description

[0015] Figure 1 A schematic diagram of the simulated water jet landing point of a conventional narrow-slit outlet is shown; Figure 2 A schematic diagram of the simulated water jet landing point of a conventional non-centrally symmetrical narrow slit outlet is shown; Figure 3This invention illustrates a plan view of a narrow slit outlet cantilever sill where the base plate and side wall are not aligned. Figure 4 A schematic diagram of the water tongue formed in Example 1 is shown; Figure 5 A schematic diagram of the water tongue formed in Example 2 is shown; Figure 6 A schematic diagram of the water tongue formed in Example 3 is shown; Figure 7 A schematic diagram of the water tongue formed in Example 4 is shown.

[0016] Legend: 1. First side wall; 2. Second side wall; 3. Third side wall; 4. Fourth side wall; 5. Base plate. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The same reference numerals in the drawings represent the same components. It should be noted that the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0018] like Figure 3 As shown, the present invention discloses a narrow-slit outlet cantilever with a non-aligned base plate and sidewalls, including a first sidewall 1, a second sidewall 2, a third sidewall 3, a fourth sidewall 4, and a base plate 5. The first sidewall 1 and the second sidewall 2 are arranged parallel to each other on both sides of the base plate 5. The first sidewall 1 is connected to the third sidewall 3, and the second sidewall 2 is connected to the fourth sidewall 4. The width between the third sidewall 3 and the fourth sidewall 4 gradually decreases along the water flow direction. There is no end alignment between the third sidewall 3, the fourth sidewall 4, and the base plate 5.

[0019] Furthermore, the third sidewall 3 contracts inward, and the slope of the contraction of the third sidewall 3 satisfies: i1=b1 / L1, where i1 is the slope of the contraction of the third sidewall, L1 is the longitudinal distance from the end of the third sidewall to the end of the first sidewall, and b1 is the lateral distance from the end of the third sidewall 3 to the end of the first sidewall.

[0020] Furthermore, the fourth side wall 4 contracts inward, and the slope of the fourth side wall 4 contracts in such a way that i2 = b2 / L2, where i2 is the slope of the fourth side wall 4, L2 is the longitudinal distance from the end of the fourth side wall 4 to the end of the second side wall 2, and b2 is the lateral distance from the end of the fourth side wall 4 to the end of the second side wall 2.

[0021] Furthermore, the end of the bottom plate 5 is perpendicular to the direction of water flow or at a certain angle, and the included angle between the end of the bottom plate 5 and the central axis satisfies: α = 15°-90°, where α is the included angle between the bottom plate 5 and the direction of water flow.

[0022] Furthermore, the width of the end of the base plate 5 satisfies: b3 = (0.2 - 0.5)B, where b3 is the width of the end of the base plate 5 and B is the distance between the first side wall 1 and the second side wall 2.

[0023] Furthermore, the longitudinal distance from the midpoint of the end of the base plate 5 to the ends of the first and second side walls is L3.

[0024] Preferably, the contraction slopes of the third sidewall 3 and the fourth sidewall 4 satisfy: i1 and i2 = 0 - 1 / 20.

[0025] Preferably, the base plate 5 is one of a circular arc surface, a horizontal surface, and a sloped surface.

[0026] Example 1 like Figure 4 As shown, the cantilever sill described in this embodiment is based on a conventional cantilever sill, where the width between the two side walls gradually decreases along the water flow direction, forming a gradually narrowing slit outlet. During the narrowing process, it is centrally symmetrical along the central axis, forming a centrally symmetrical narrow slit cantilever sill, and changing the position of the end of the bottom plate 5. The cantilever sill width B=7.7m, b1=b2=3m, b3=2.4m, L1=L2=38.1m, L3=34.3m, α=90°.

[0027] Numerical simulation results show that the water tongue landing point is compared to Figure 1 In the conventional narrow-slit weir design, the lower edge water jet is released earlier, significantly elongating the longitudinal impact point of the water jet and allowing for more thorough dispersion of the water jet into the water, thus reducing downstream scouring. The water inflow point shape and numerically simulated water jet morphology in this embodiment are as follows: Figure 4 As shown.

[0028] Example 2 like Figure 5 As shown, the cantilever embankment described in this embodiment is based on a non-centrally symmetrical cantilever embankment. The width between the two side walls of the cantilever embankment gradually decreases along the water flow direction, forming a gradually narrowing slit outlet. The lateral distances between the third and fourth side walls are unequal, forming a non-centrally symmetrical narrow-slit cantilever embankment, and one side wall of the non-centrally symmetrical narrow-slit cantilever embankment is shortened. The cantilever embankment widths are B=7.7m, b1=1m, b2=4.9m, b3=1.8m, L1=34.3m, L2=L3=38.1m, and α=90°. The cantilever embankment is located above the side wall of the cushion pond and needs to guide the water jet so that it falls into the cushion pond, avoiding erosion of the cushion pond slope.

[0029] Numerical simulation results show that the water tongue landing point is compared to Figure 1 The conventional narrow-slit weir exhibited a significant deflection, with the vast majority of the water flow falling into the inner pool. Compared to the conventional asymmetric narrow-slit weir, the overall deflection of the water jet was greater, and the scattered water jet disappeared. The shape of the water inflow point and the numerically simulated water jet morphology in this embodiment are as follows: Figure 5 As shown.

[0030] Example 3 like Figure 6 As shown, the cantilever embankment described in this embodiment is based on a conventional cantilever embankment. The width between the two side walls of the cantilever embankment gradually decreases along the water flow direction, forming a gradually narrowing slit outlet. During the narrowing process, it is centrally symmetrical along the central axis, forming a centrally symmetrical narrow slit cantilever embankment, and the narrow slit outlet is beveled. The cantilever embankment widths are B=7.7m, b1=2.8m, b2=3m, b3=2m, L1=36.1m, L2=38.1m, L3=37.2m, and α=45°. The cantilever embankment is located above the side wall of the cushion pond and needs to guide the water jet so that it falls into the cushion pond, avoiding erosion of the cushion pond slope.

[0031] Numerical simulation results show that the water tongue landing point is compared to Figure 1 The conventional narrow-slit weir showed a significant deflection, with the vast majority of the water flow landing inside the cushion pond, a marked improvement compared to the conventional narrow-slit weir where the entire water jet falls onto the bank slope. The shape of the water inflow point and the numerically simulated water jet morphology in this embodiment are shown below. Figure 6 As shown.

[0032] Example 4 like Figure 7 As shown, the cantilever embankment described in this embodiment is based on a conventional cantilever embankment. The width between the two side walls of the cantilever embankment gradually decreases along the water flow direction, forming a gradually narrowing slit outlet. During the narrowing process, it is not centrally symmetrical along the central axis; the slit outlet is biased to one side, forming a non-centrally symmetrical slit cantilever embankment. The slit outlet is beveled. The cantilever embankment widths are B=7.7m, b1=0.9m, b2=4.9m, b3=1.9m, L1=37.9m, L2=38.1m, L3=37.8m, and α=80°. The cantilever embankment is located above the side wall of the cushion pond and needs to guide the water jet so that it falls into the cushion pond, avoiding erosion of the cushion pond slope.

[0033] Hydraulic experiments showed that when the water inlet point was located inside the cushion pond, the spalling of the top water jet was controlled, compared to... Figure 2 The water jet at the top of the middle section showed significantly reduced dispersion, and it did not impact the sidewalls of the water cushion pond. The shape of the water inflow point and the water jet morphology in the hydraulic model test in this embodiment are as follows: Figure 7 As shown.

[0034] The above description of the embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A narrow sill with a non-aligned base plate and side wall, characterized in that: It includes a first side wall (1), a second side wall (2), a third side wall (3), a fourth side wall (4), and a base plate (5). The first side wall (1) and the second side wall (2) are arranged parallel to each other on both sides of the base plate (5). The first side wall (1) is connected to the third side wall (3), and the second side wall (2) is connected to the fourth side wall (4). The width between the third side wall (3) and the fourth side wall (4) gradually decreases along the direction of water flow. The ends of the third side wall (3), the fourth side wall (4), and the base plate (5) are not flush.

2. The narrow slit outlet cantilever sill with misalignment between the base plate and the side wall as described in claim 1, characterized in that: The third sidewall (3) contracts inward, and the contraction slope of the third sidewall (3) satisfies: i1=b1 / L1, where i1 is the contraction slope of the third sidewall (3), L1 is the longitudinal distance from the end of the third sidewall (3) to the end of the first sidewall (1), and b1 is the lateral distance from the end of the third sidewall (3) to the end of the first sidewall (1).

3. The narrow slit outlet cantilever sill with misalignment between the base plate and the side wall as described in claim 2, characterized in that: The fourth side wall (4) contracts inward, and the slope of the fourth side wall (4) is satisfied with: i2=b2 / L2, where i2 is the slope of the fourth side wall (4), L2 is the longitudinal distance from the end of the fourth side wall (4) to the end of the second side wall (2), and b2 is the lateral distance from the end of the fourth side wall (4) to the end of the second side wall (2).

4. The narrow slit outlet cantilever sill with misalignment between the base plate and the side wall as described in claim 3, characterized in that: The contraction slopes i1 and i2 of the third sidewall (3) and the fourth sidewall (4) are both greater than or equal to 0 and less than or equal to 1 / 20.

5. The narrow slit outlet cantilever sill with misalignment between the base plate and the side wall as described in claim 1, characterized in that: The included angle between the end of the base plate (5) and the central axis satisfies: α = 15° - 90°, where α is the included angle between the base plate (5) and the central axis.

6. The narrow slit outlet cantilever sill with misalignment between the base plate and the side wall as described in claim 1, characterized in that: The width of the end of the base plate (5) satisfies: b3 = (0.2-0.5)B, where b3 is the width of the end of the base plate (5) and B is the distance between the first side wall (1) and the second side wall (2).

7. The narrow slit outlet cantilever sill with misalignment between the base plate and the side wall as described in claim 1, characterized in that: The longitudinal distance from the midpoint of the end of the base plate (5) to the end of the first side wall (1) and the second side wall (2) is L3.

8. The narrow slit outlet cantilever sill with non-aligned base plate and side wall as described in any one of claims 1 to 7, characterized in that: The base plate (5) is one of the following: a circular arc surface, a horizontal surface, and a sloped surface.

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