A device and method for adjusting water flow inlet of bend in river engineering model test

Abstract

The present invention relates to the technical field of devices for adjusting water flow at the inlet of a bend, and more specifically, to a device and method for adjusting water flow at the inlet of a bend in a river engineering model test. The device comprises a diversion device and a grating plate. The diversion device comprises a water-blocking structure, a diversion pipe front plate, a diversion pipe, and a diversion pipe rear plate. The diversion pipe front plate and the diversion pipe rear plate are respectively provided at both ends of the bottom of the water-blocking structure. A plurality of diversion pipes are provided between the diversion pipe front plate and the diversion pipe rear plate. The grating plate and the diversion device are sequentially arranged in the river channel along the direction of water flow, and the diversion device and the river engineering model are connected by a slope. Using this device effectively ensures that the inlet water flow direction of the river engineering model test is directed straightly toward the river engineering model river channel, and the inlet water flow remains stable and slow, without suffering from large-scale turbulence. The inlet water flow velocity distribution is also more uniform, and the device has the advantages of simple operation and high application value.

Description

Technical Field

[0001] The invention relates to the technical field of water flow regulating devices for bend inlets, and in particular to a device and method for regulating water flow at bend inlets in river engineering model tests. Background Art

[0002] Water supply for river model tests typically involves connecting the water supply pipe directly to the river model. Due to the constraints of the test site, the water flow in the river model's water supply often forms a certain angle with its inlet, preventing the water from flowing directly into the river model's channel. This inability to flow directly into the river model's channel seriously interferes with the actual hydrodynamic parameters of the channel, resulting in the river model being unable to effectively simulate the inlet flow conditions. To ensure that the river model can effectively simulate the inlet flow conditions, the inlet flow direction of the river model test should be directly pointed toward the model channel, and the inlet flow should be kept steady and slow, minimizing large-scale turbulence and ensuring a more uniform flow velocity distribution. Summary of the Invention

[0003] In order to solve the problem that the water flow of the river engineering model water supply usually forms a certain angle with its inlet, the water flow cannot enter the river channel of the river engineering model straightly, which will seriously interfere with the various hydrodynamic parameters of the actual water flow in the river channel, resulting in the river engineering model being unable to effectively simulate the water flow conditions of the river channel inlet, the present invention provides a device and method for adjusting the water flow at the inlet of the river engineering model test bend.

[0004] In order to achieve the above-mentioned object, the present invention provides, in a first aspect, a device for adjusting water flow at the inlet of a bend in a river engineering model test, the device comprising a flow guide device and a grid plate;

[0005] The flow guide device includes a water blocking structure, a flow guide pipe front plate, a flow guide pipe and a flow guide pipe rear plate. The two ends of the bottom of the water blocking structure are respectively provided with the flow guide pipe front plate and the flow guide pipe rear plate. A plurality of the flow guide pipes are provided between the flow guide pipe front plate and the flow guide pipe rear plate.

[0006] Wherein, along the direction of water flow, the grid plate and the diversion device are sequentially arranged in the river channel, and the diversion device and the river model are connected via a slope.

[0007] Preferably, the height of the diversion device is greater than the height of the water surface of the first river channel, and the width of the diversion device is the same as the width of the first river channel.

[0008] Preferably, the height of the grating plate is greater than the height of the water surface of the second river channel, and the width of the grating plate is the same as the width of the second river channel.

[0009] Preferably, a plurality of water outlet holes are provided on the surface of the grille plate.

[0010] Preferably, the guide tube front plate and the guide tube rear plate are of the same size, and the guide tube front plate and the guide tube rear plate are respectively and parallelly arranged at two ends of the bottom of the water blocking structure.

[0011] Preferably, a plurality of circular holes for installing the flow guide pipes are correspondingly provided on the surfaces of the flow guide pipe front plate and the flow guide pipe rear plate.

[0012] Preferably, the cumulative setting height of the plurality of guide pipes is the same as the elevation of the inflow end of the river model.

[0013] A second aspect of the present invention provides a method for adjusting water flow at the inlet of a river model test bend, which is applied to the above-mentioned device for adjusting water flow at the inlet of a river model test bend. The method comprises:

[0014] The grid plates and the diversion devices are sequentially arranged in the river channel along the direction of water flow;

[0015] The outflow ends of the plurality of guide pipes are connected to the inflow end of the river model via the slope.

[0016] Preferably, a bend area is provided between the grid plate and the flow guide device, the outflow end of the grid plate is connected to the inflow end of the bend area, and the outflow end of the bend area is connected to the inflow end of the flow guide device.

[0017] Preferably, a steady flow zone is set between the outflow ends of several of the guide pipes and the inflow end of the river engineering model, and the steady flow zone includes a deep groove and the slope. The outflow ends of several of the guide pipes are connected to the inflow ends of the deep groove, the outflow end of the deep groove is connected to the inflow end of the slope, and the outflow end of the slope is connected to the inflow end of the river engineering model.

[0018] According to the above technical solution, based on the device for adjusting the inlet water flow of the river engineering model test bend, in actual application, by arranging the grating plate and the diversion device in the river channel in sequence, and connecting the diversion device and the river engineering model through a slope, it is effectively ensured that the inlet water flow direction of the river engineering model test points straight to the river engineering model river channel, and the inlet water flow remains stable and slow without suffering from large-scale turbulence. At the same time, the inlet water flow velocity distribution of the river engineering model is also relatively uniform, which has the advantages of simple operation and high application value.

[0019] At the same time, by setting the height of the diversion device to be greater than the height of the water surface of the first river channel, the width of the diversion device is the same as the width of the first river channel, so as to ensure that the water flow is diverted through the diversion pipe and then flows out along the inflow end of the river model, thereby ensuring the stability of the water flow.

[0020] By setting the height of the grating plate to be greater than the height of the water surface of the second river channel, the width of the grating plate is the same as the width of the second river channel, and a plurality of water outlet holes are provided on the surface of the grating plate to preliminarily weaken the turbulent water flow and allow the water flow to smoothly enter the guide pipe.

[0021] By setting the cumulative setting height of a plurality of the guide pipes to be the same as the elevation of the inflow end of the river model, the stability of the water flow when entering the river model can be guaranteed to the greatest extent.

[0022] By setting a bend area between the grid plate and the diversion device, the angle of water flow entering the inflow ends of the diversion pipes is adjusted, so that the water flow enters the inflow ends of the diversion pipes smoothly, thereby playing a certain diversion role.

[0023] By setting a steady flow zone between the outflow ends of several of the diversion pipes and the inflow end of the river model, the water flow in the steady flow zone uses its own gravity to redistribute the kinetic energy of the water flow, which not only further stabilizes the flow state, but also makes the flow velocity distribution of the water entering the river model more uniform. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the three-dimensional structure of a device used for adjusting the water flow at the inlet of a bend in river engineering model tests;

[0025] Figure 2 This is a cross-sectional view of a device used for adjusting the water flow at the inlet of a bend in river engineering model tests;

[0026] Figure 3 This is a cross-sectional view of a diversion device used for adjusting the water flow at the inlet of a bend in river engineering model tests;

[0027] Figure 4 It is a schematic diagram of the three-dimensional structure of the bend area;

[0028] Figure 5 It is a schematic diagram of the three-dimensional structure of the steady flow area;

[0029] Figure 6 It is a flow chart of a method for adjusting water flow at the inlet of a bend in a river engineering model test;

[0030] Figure 7 The present invention is a structural schematic diagram of an embodiment of a device for adjusting water flow at a bend inlet in a river engineering model test.

[0031] Description of Reference Numerals

[0032] Diversion device 1; water blocking structure 2; diversion pipe front plate 3; diversion pipe 4; diversion pipe rear plate 5;

[0033] Grille plate 6; water outlet 7; slope 8; river engineering model 9. DETAILED DESCRIPTION

[0034] The following describes the specific implementation of the embodiment of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the embodiment of the present invention and is not used to limit the embodiment of the present invention.

[0035] In the present invention, unless otherwise stated, directional words such as "up, down, left, right" generally refer to the direction of the direction. Figure 1 The up, down, left and right directions of the device shown are used for adjusting the water flow at the inlet of the bend in river engineering model tests.

[0036] The first aspect of the present invention provides a device for adjusting the water flow at the inlet of a bend in a river model test, such as Figure 1-5 As shown, the device for adjusting the water flow at the inlet of a bend in a river model test includes a flow guide device 1 and a grid plate 6;

[0037] The flow guide device 1 includes a water blocking structure 2, a flow guide tube front plate 3, a flow guide tube 4 and a flow guide tube rear plate 5. The flow guide tube front plate 3 and the flow guide tube rear plate 5 are respectively provided at both ends of the bottom of the water blocking structure 2. A plurality of the flow guide tubes 4 are provided between the flow guide tube front plate 3 and the flow guide tube rear plate 5.

[0038] Wherein, along the direction of water flow, the grid plate 6 and the diversion device 1 are sequentially arranged in the river channel, and the diversion device 1 and the river model 9 are connected via a slope 8 .

[0039] According to the above technical solution, based on the device for adjusting the inlet water flow of the river engineering model test bend, in actual application, by arranging the grating plate and the diversion device in the river channel in sequence, and connecting the diversion device and the river engineering model through a slope, it is effectively ensured that the inlet water flow direction of the river engineering model test points straight to the river engineering model river channel, and the inlet water flow remains stable and slow without suffering from large-scale turbulence. At the same time, the inlet water flow velocity distribution of the river engineering model is also relatively uniform, which has the advantages of simple operation and high application value.

[0040] According to a preferred embodiment of the present invention, the height of the diversion device 1 is greater than the height of the water surface of the first river channel, and the width of the diversion device 1 is the same as the width of the first river channel.

[0041] In an embodiment of the present invention, the diversion device 1 is arranged at the first river channel in a direction perpendicular to the river model 9. The height of the diversion device 1 is greater than the height of the water surface of the first river channel where it is specifically set. The width of the diversion device 1 is the same as the width of the first river channel to ensure that the water flow is diverted through the diversion pipe and then flows out along the inflow end of the river model, thereby ensuring the stability of the water flow.

[0042] According to a preferred embodiment of the present invention, the height of the grating plate 6 is greater than the height of the water surface of the second river channel, and the width of the grating plate 6 is the same as the width of the second river channel.

[0043] Furthermore, a plurality of water outlet holes 7 are provided on the surface of the grid plate 6 .

[0044] In an embodiment of the present invention, the grating plate 6 is vertically arranged at the second river channel, the height of the grating plate 6 is greater than the height of the water surface of the second river channel where it is specifically arranged, the width of the grating plate 6 is the same as the width of the second river channel, and a plurality of water outlet holes are provided on the surface of the grating plate 6 to preliminarily weaken the turbulent water flow so that the water flow smoothly enters the guide pipe 4.

[0045] According to a preferred embodiment of the present invention, the guide tube front plate 3 and the guide tube rear plate 5 are of the same size, and are respectively and parallelly arranged at both ends of the bottom of the water blocking structure 2 .

[0046] Furthermore, a plurality of circular holes for installing the guide tube 4 are correspondingly provided on the surfaces of the guide tube front plate 3 and the guide tube rear plate 5 .

[0047] Furthermore, the cumulative setting height of the plurality of guide pipes 4 is the same as the elevation of the inflow end of the river model 9 .

[0048] In an embodiment of the present invention, the guide tube front plate 3 and the guide tube rear plate 5 are of the same size and are disposed parallel to each other at the two ends of the bottom of the water-blocking structure 2. A plurality of circular holes having a diameter equal to that of the guide tubes 4 are disposed at corresponding positions on the surfaces of the guide tube front plate 3 and the guide tube rear plate 5. The guide tubes 4 are disposed parallel to each other between the guide tube front plate 3 and the guide tube rear plate 5 through the circular holes. The cumulative height of the guide tubes 4 in any longitudinal row, along a direction perpendicular to the riverbed, is the same as the elevation of the inflow end of the river model 9. The diameter of the guide tubes 4 depends on the size of the river model 9.

[0049] The second aspect of the present invention also provides a method for adjusting the water flow at the inlet of a river model test bend, which is applied to the above-mentioned device for adjusting the water flow at the inlet of a river model test bend, such as Figure 6 As shown, the method includes the following steps:

[0050] S1. Place the grid plate 6 and the diversion device 1 in the river channel in sequence along the water flow direction;

[0051] S2. The outflow ends of the plurality of guide pipes 4 are connected to the inflow end of the river model 9 via the slope 8.

[0052] Furthermore, a bend area is provided between the grid plate 6 and the flow guiding device 1 , the outflow end of the grid plate 6 is connected to the inflow end of the bend area, and the outflow end of the bend area is connected to the inflow end of the flow guiding device 1 .

[0053] Furthermore, a steady flow zone is set between the outflow ends of several of the guide pipes 4 and the inflow end of the river engineering model 9, and the steady flow zone includes a deep groove and the slope 8. The outflow ends of several of the guide pipes 4 are connected to the inflow ends of the deep grooves, the outflow ends of the deep grooves are connected to the inflow ends of the slope 8, and the outflow end of the slope 8 is connected to the inflow end of the river engineering model 9.

[0054] In an embodiment of the present invention, the grating plate 6 is vertically arranged at the inflow end of the bend area, and the two ends of the grating plate 6 are respectively connected to the river bank surfaces on both sides of the inflow end of the bend area; the diversion device 1 is arranged at the outflow end of the bend area in a direction perpendicular to the river engineering model 9, and the two ends of the diversion device 1 through which the non-water flow flows are respectively connected to the river bank surfaces on both sides of the outlet end of the bend area; the deep trough and the slope 8 are formed by manual or mechanical excavation. In actual application, the water flow first enters the bend area after preliminary stabilization through the grating plate 6. Under the action of the bend area, the water flow smoothly flows into the several diversion pipes 4, and after being diverted by the several diversion pipes 4, it points to the inflow end of the river engineering model 9. Then, the water flow flowing out of the several diversion pipes 4 slowly rises under the action of the deep trough and the slope 8, and then smoothly flows into the river engineering model 9.

[0055] The concept of the present invention is described below with reference to five specific embodiments.

[0056] like Figure 7 As shown, the inflow direction of the river model's water supply forms a 45° angle with the extension of the inflow end of River Model 9. This results in a turbulent flow upon entering River Model 9, and an uneven velocity distribution at the inlet section of River Model 9, with a pronounced increase on the right side and decrease on the left. This will affect the hydrodynamic parameters of the inlet flow of River Model 9 and ultimately the test results. To address this issue, we plan to conduct the following optimization experiments.

[0057] ① A grid plate 6 is provided at the inflow end of the bend area;

[0058] ② Set a slope 8 at the front end of the inlet of the river model 9, and connect it to the inlet of the river model 9 through a 1:5 slope 8;

[0059] ③ A flow guide device 1 is set at the outflow end of the bend area, wherein the diameter of the flow guide pipe 4 is 7 cm.

[0060] The following five sets of test examples were specifically conducted. Each set of test examples included a grating plate 6 installed at the inlet end of the bend to initially adjust and stabilize the inlet water flow. The inlet elevations of Examples 1 and 2 were identical to those of the river model 9. Examples 3 through 5 included a slope 8 installed at the front end of the inlet of the river model 9. The specific test examples are shown in Table 1 below.

[0061] Table 1: Test Examples

[0062]

[0063] Example 1

[0064] Table 2 shows the velocity distribution of the cross section near the inlet of River Model 9. After the inlet water passes through the frontmost grid plate 6, the flow pattern is generally stable, pointing toward the right bank. Due to the 45° angle between the flow direction and River Model 9, the water flow at the inlet of River Model 9 forms a clear distribution with higher velocity on the right and lower velocity on the left. The maximum velocity on the right is approximately 4 to 6 times the minimum velocity on the left. A backflow area exists on the left side of the inlet of River Model 9, and the water flow at the inlet of River Model 9 fluctuates significantly.

[0065] Table 2: Flow velocity distribution of Example 1 (unit: cm / s)

[0066]

[0067] Example 2

[0068] Example 2 builds on Example 1 by adding a diversion device 1 (several diversion tubes 4 are cumulatively installed above the water surface). Due to the influence of the diversion tubes 4, the water flow at the inlet of the river model 9 exhibits slight fluctuations, and the left-side backflow phenomenon essentially disappears. The flow velocity distribution at the inlet of the river model 9 also shows a clear pattern of higher velocities on the right and lower velocities on the left, showing little improvement compared to Example 1. See Table 3 for the flow velocity distribution of Example 2.

[0069] Table 3: Flow velocity distribution of Example 2 (unit: cm / s)

[0070]

[0071] Example 3

[0072] Example 3 builds on Example 1 by installing a slope 8 at the front end of the inlet of the river model 9, connecting it to the inlet of the river model 9 via the slope 8. In Example 3, there is no backflow in the area to the left of the inlet of the river model 9, and the water flow fluctuations are reduced compared to Example 1. The flow velocity distribution still shows a high flow velocity on the right and a low flow velocity on the left, but the degree of unevenness is significantly reduced. See Table 4 for the flow velocity distribution of Example 3.

[0073] Table 4: Flow velocity distribution of Example 3 (unit: cm / s)

[0074]

[0075] Example 4

[0076] Example 4 adds a diversion device 1 to Example 3 (several diversion tubes 4 are cumulatively installed above the water surface). This directs the flow downstream, significantly reducing flow fluctuations compared to Example 3, and maintaining overall flow stability. Flow velocity distribution also shows a high velocity on the right side and a low velocity on the left side at the inlet of the river model 9. This unevenness is further reduced compared to Example 3, and the velocity distribution becomes increasingly uniform as one moves downstream. See Table 5 for the velocity distribution of Example 4.

[0077] Table 5: Flow velocity distribution of Example 4 (unit: cm / s)

[0078]

[0079] Example 5

[0080] Example 5 builds on Example 3 by adding a diversion device 1 (the cumulative height of several diversion pipes 4 is below the water surface, but at the same elevation as the inlet of river model 9). Due to the water blocking effect of the shore and water-blocking structure 2, the surface water forms a counterclockwise backflow in the upstream area. After flowing through the diversion pipe 4, the water slowly rises due to the water stabilization effect of the slope 8, and eventually flows smoothly to the river model 9. The water flow at the inlet of river model 9 is stable, with no obvious fluctuations. The flow velocity distribution of each section is generally uniform, with further reduction in unevenness compared to Example 4, indicating a good optimization effect. See Table 6 for the flow velocity distribution of Example 5.

[0081] Table 6: Flow velocity distribution of Example 5 (unit: cm / s)

[0082]

[0083] Furthermore, the uniformity of the cross-sectional flow velocity is analyzed, and the cross-sectional flow velocity non-uniformity coefficient ξ is introduced to characterize the uniformity distribution of the cross-sectional flow velocity. The larger the non-uniformity coefficient, the more non-uniform the cross-sectional flow velocity. The formula is as follows:

[0084]

[0085] Where V max is the maximum average flow velocity of the section, V min is the minimum average flow velocity of the section, V avx is the average flow velocity at each measuring point in the section.

[0086] The uneven coefficient of flow velocity in the sections of each embodiment is shown in Table 7. It can be seen that the uneven coefficients of Examples 3 to 5 are significantly lower than those of Examples 1 and 2, indicating that the optimization scheme ②, i.e., setting a slope 8 at the front end of the inlet of the river model 9, can significantly improve the uniformity of the flow velocity distribution at the inlet of the river model 9. In Example 5, i.e., setting a diversion device 1 at the bottom of the slope 8, and the cumulative setting height of several diversion pipes 4 is the same as the elevation of the river model 9, has the smallest uneven coefficient and the best effect.

[0087] Table 7: Cross-sectional flow velocity non-uniformity coefficient of each embodiment

[0088]

[0089] The device and method for adjusting the water flow at the inlet of a river model test bend provided by the present invention, during actual application, by sequentially arranging the grating plate and the diversion device in the river channel, and connecting the diversion device and the river model via a slope, effectively ensures that the inlet water flow direction of the river model test points straightly to the river model river channel, and the inlet water flow remains stable and slow without suffering from large-scale turbulence. At the same time, the flow velocity distribution of the inlet water flow of the river model is also relatively uniform, and the device has the advantages of simple operation and high application value.

[0090] While the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited thereto. Within the technical scope of the present invention, various simple variations of the technical solution of the present invention may be made. To avoid unnecessary repetition, the present invention will not further describe various possible combinations. However, these simple variations and combinations should also be considered as disclosed herein and fall within the scope of protection of the present invention.

Claims

1. A device for adjusting water flow at the inlet of a bend in a river model test, characterized in that: The device for adjusting water flow at the inlet of a river model test bend comprises a flow guide device (1) and a grid plate (6); The flow guide device (1) comprises a water blocking structure (2), a flow guide pipe front plate (3), a flow guide pipe (4) and a flow guide pipe rear plate (5); the flow guide pipe front plate (3) and the flow guide pipe rear plate (5) are respectively provided at both ends of the bottom of the water blocking structure (2); and a plurality of the flow guide pipes (4) are provided between the flow guide pipe front plate (3) and the flow guide pipe rear plate (5); Wherein, along the direction of water flow, the grid plate (6) and the diversion device (1) are sequentially arranged in the river channel, and the diversion device (1) and the river model (9) are connected via a slope (8); A bend area is provided between the grid plate (6) and the flow guide device (1), the outflow end of the grid plate (6) is connected to the inflow end of the bend area, and the outflow end of the bend area is connected to the inflow end of the flow guide device (1); The height of the grating plate (6) is greater than the height of the water surface of the second river channel, and the width of the grating plate (6) is the same as the width of the second river channel; The height of the diversion device (1) is greater than the height of the water surface of the first river channel, and the width of the diversion device (1) is the same as the width of the first river channel; The cumulative setting height of the plurality of diversion pipes (4) is the same as the elevation of the inflow end of the river model (9); A steady flow area is provided between the outflow ends of the plurality of guide pipes (4) and the inflow end of the river model (9), the steady flow area comprising a deep trough and the slope (8), the outflow ends of the plurality of guide pipes (4) being connected to the inflow end of the deep trough, the outflow end of the deep trough being connected to the inflow end of the slope (8), and the outflow end of the slope (8) being connected to the inflow end of the river model (9).

2. The device for adjusting water flow at the inlet of a river model test bend according to claim 1, characterized in that: A plurality of water outlet holes (7) are provided on the surface of the grid plate (6).

3. The device for adjusting water flow at the inlet of a river model test bend according to claim 1, characterized in that: The guide tube front plate (3) and the guide tube rear plate (5) are of the same size, and the guide tube front plate (3) and the guide tube rear plate (5) are respectively arranged in parallel at two ends of the bottom of the water blocking structure (2).

4. The device for adjusting water flow at the inlet of a river model test bend according to claim 1 or 3, characterized in that: The surfaces of the guide tube front plate (3) and the guide tube rear plate (5) are correspondingly provided with a plurality of circular holes for mounting the guide tube (4).

5. A method for adjusting water flow at the inlet of a river model test bend, applied to the device for adjusting water flow at the inlet of a river model test bend as claimed in any one of claims 1 to 4, characterized in that: The method for adjusting the water flow at the inlet of a bend in a river engineering model test comprises: The grid plate (6) and the diversion device (1) are sequentially arranged in the river channel along the direction of water flow; The outflow ends of the plurality of guide pipes (4) are connected to the inflow end of the river model (9) via the slope (8); A bend area is provided between the grid plate (6) and the flow guide device (1), the outflow end of the grid plate (6) is connected to the inflow end of the bend area, and the outflow end of the bend area is connected to the inflow end of the flow guide device (1); A steady flow area is provided between the outflow ends of the plurality of guide pipes (4) and the inflow end of the river model (9), the steady flow area comprising a deep trough and the slope (8), the outflow ends of the plurality of guide pipes (4) being connected to the inflow end of the deep trough, the outflow end of the deep trough being connected to the inflow end of the slope (8), and the outflow end of the slope (8) being connected to the inflow end of the river model (9).

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