A test method for testing the flow-blocking characteristics of pile-based hollow breakwater

Abstract

The invention discloses a test method for testing the flow resistance characteristics of a pile-based hollow breakwater, which relates to the technical field of breakwater flow resistance characteristics test, and includes the following steps: S1: determining the size of a test water tank and a model scale; S2: configuring a test water tank, and setting a pile-based hollow breakwater model in the test water tank; S3: determining the upstream and downstream water flow stable areas, and selecting a test section in the upstream and downstream water flow stable areas respectively; S4: performing a characteristic test, and obtaining the water depth and average flow velocity of the upstream test section and the downstream test section after the flow field is stable; S5: calculating the head loss and water flow resistance of the hydrodynamic field caused by the pile-based hollow breakwater model based on the energy equation and the momentum equation. The method of the invention fully considers the structural complexity of the pile-based hollow breakwater, and can quickly and accurately carry out the flow resistance characteristics test.

Description

Technical Field

[0001] The invention relates to the technical field of test of flow resistance characteristics of breakwaters, and in particular to a test method for testing the flow resistance characteristics of a pile-foundation hollow breakwater. Background Art

[0002] The coastal zone is the area where the ocean and land meet. There are strong nonlinear interactions between factors such as waves, tides and storm surges. The dynamic environment is complex and it is very easy to suffer from disasters such as coastal erosion, submergence and structure damage. Breakwaters, as an important coastal engineering structure, can effectively reduce the invasion of waves on port coasts.

[0003] Traditional impermeable breakwaters will hinder the flow of water and significantly change the surrounding hydrodynamic environment. Pile-based hollow breakwaters are environmentally friendly and can adapt to a variety of sensitive coastal environments. They allow water to pass through while ensuring wave resistance, reducing negative impacts on the environment. Therefore, pile-based hollow breakwaters have gradually received attention in recent years.

[0004] The current research on wave dissipation capacity and flow resistance characteristics is mostly aimed at simple structures with relatively regular structural types or single piles. The method is to set point pressure sensors on simple structures with relatively regular structural types or single piles, and then perform integral calculations along the surface of the simple structure. Pile-based hollow breakwaters are composed of complex piles, plates, and beams. Therefore, the above method cannot be used when conducting flow resistance characteristics research on pile-based hollow breakwaters with complex structures.

[0005] In view of this, this invention is proposed. Summary of the invention

[0006] The purpose of the present invention is to solve the shortcomings existing in the prior art, and to propose a test method for testing the flow resistance characteristics of a pile-based hollow breakwater, which fully considers the structural complexity of the pile-based hollow breakwater and can quickly and accurately carry out flow resistance characteristics testing.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A test method for testing the flow-blocking characteristics of a pile-based permeable breakwater comprises the following steps:

[0009] S1: Determine the target sea area, collect the environmental factors of the target sea area, and determine the size of the test tank and the scale of the model according to the environmental factors of the target sea area;

[0010] S2: Configure the test water tank according to the size of the test water tank and the scale of the model, and set up a pile-foundation hollow breakwater model in the test water tank;

[0011] S3: According to the environmental factors of the target sea area and the model scale, the initial water depth and flow velocity are set for preliminary testing. After the flow field is stable, the vertical flow velocity distribution of multiple upstream and downstream preliminary test sections is obtained, the upstream and downstream water flow stable areas are determined, and a test section is selected in the upstream and downstream water flow stable areas respectively;

[0012] S4: According to the environmental factors of the target sea area and the model scale, set the initial water depth and flow velocity to conduct characteristic test. After the flow field is stable, obtain the water depth and average flow velocity of the upstream test section and the downstream test section;

[0013] S5: Obtain the water depth and average flow velocity of the upstream and downstream test sections after the flow field is stabilized in the characteristic test experiment, and calculate the head loss and water flow resistance of the hydrodynamic field caused by the pile-based permeable breakwater model based on the energy equation and momentum equation.

[0014] Furthermore, the scale in S1 includes a length scale and a flow rate scale.

[0015] Further, the S1 includes:

[0016] S11: determine the target sea area, collect the water depth and flow velocity of the target sea area, and calculate the Froude number of the target sea area;

[0017] S12: Configure the test tank size and determine the model scale so that the Froude number of the test environment and the Froude number of the target sea area meet the gravity similarity criterion.

[0018] Furthermore, the pile-based hollow breakwater model in S2 includes: an upper open-hole wave-breaking structure and a lower supporting pile; the open-hole wave-breaking structure has an inwardly concave arc surface facing upstream and is provided with a plurality of through holes, and the open-hole wave-breaking structure has an inwardly vertical surface facing downstream and is provided with a through hole; there are at least two supporting piles, and the supporting piles are angular structures, and are provided with a plurality of through holes.

[0019] Further, in S1, the environmental factors of the target sea area collected include water depth and current velocity, and the determined model scales include length scale and current velocity scale;

[0020] The S3 comprises the following steps:

[0021] S31: According to the water depth and flow velocity of the target sea area, as well as the length scale and flow velocity scale, set the initial water depth and flow velocity for preliminary testing;

[0022] S32: Select multiple pre-test sections at the upstream and downstream, and continuously collect the water depth and flow velocity of each pre-test section, and judge whether the flow field is stable according to the continuously collected water depth and flow velocity of each pre-test section, and execute S33 after the flow field is stable;

[0023] S33: according to the water depth of each pre-test section, select a number of flow velocity collection points in the vertical direction of each pre-test section, and then respectively collect the flow velocity at each flow velocity collection point in the vertical direction of each pre-test section, and then respectively draw the vertical flow velocity curve of each pre-test section;

[0024] S34: Determine the upstream and downstream water turbulence areas and water smooth areas according to the vertical flow velocity curves of each pre-test section, and then select a pre-test section in the upstream and downstream water smooth areas as the test section.

[0025] Further, in S1, the environmental factors of the target sea area collected include water depth and current velocity, and the determined model scales include length scale and current velocity scale;

[0026] The S4 comprises the following steps:

[0027] S41: According to the water depth and flow velocity of the target sea area, as well as the length scale and flow velocity scale, set the initial water depth and flow velocity to conduct characteristic test;

[0028] S42: continuously collecting the water depth and flow velocity of the upstream test section and the downstream test section, and judging whether the flow field is stable according to the continuously collected water depth and flow velocity of the upstream test section and the downstream test section, and executing S43 after the flow field is stable;

[0029] S43: According to the water depths of the upstream test section and the downstream test section, flow velocity collection points are selected in the vertical direction of the upstream test section and the downstream test section respectively, and then the flow velocities at each flow velocity collection point in the vertical direction of the upstream test section and the downstream test section are collected respectively, and then the average flow velocities of the upstream test section and the downstream test section are calculated.

[0030] Further, the S43 comprises the following steps:

[0031] S431: According to the water depths of the upstream test section and the downstream test section, the water depths of 0.2 times, 0.6 times and 0.8 times from the water surface in the vertical direction of the upstream test section and the downstream test section are selected as flow velocity collection points;

[0032] S432: Collect the flow velocities at each flow velocity collection point in the vertical direction of the upstream test section and the downstream test section respectively, and calculate the average flow velocities of the upstream test section and the downstream test section according to the following formula:

[0033] ,

[0034] In the formula, U is the average flow velocity of the test section, and the subscripts 0.2, 0.6, and 0.8 represent the flow velocities at 0.2 times, 0.6 times, and 0.8 times the water depth from the water surface, respectively.

[0035] Furthermore, in S5, based on the energy equation and momentum equation, the following formulas are used to calculate the head loss between the upstream and downstream test sections caused by the pile-based hollow breakwater model and the comprehensive water flow resistance of the hydrodynamic field caused by the pile-based hollow breakwater model:

[0036] ,

[0037] ,

[0038] In the formula, △H is the head loss between the upstream and downstream test sections caused by the pile-based hollow breakwater model, U1 is the average flow velocity of the upstream test section, U2 is the average flow velocity of the upstream test section, h1 is the water depth of the upstream test section, h2 is the water depth of the upstream test section, g is the gravitational acceleration, ρ is the water density, B is the size of the pile-based hollow breakwater model in the width direction of the test water tank, and F is the comprehensive water flow resistance of the hydrodynamic field caused by the pile-based hollow breakwater model.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 1. A test pile-based hollow breakwater model is set up in the test environment, which fully considers the structural complexity of the pile-based hollow breakwater. During the test, only the water depth and flow velocity need to be obtained, so the test efficiency is faster and the test time is shorter. After obtaining the water depth and flow velocity, the flow resistance characteristics of the pile-based hollow breakwater in the target sea area are determined based on the energy equation and momentum equation, so the test results have high accuracy and reliability.

[0041] 2. Through the scheme of the present invention, the influence mechanism of pile-based hollow breakwater on tides and nearshore currents can be revealed more accurately, which can be used to analyze the influence of breakwater on the evolution of the ocean current environment in the overall project area, thereby providing a scientific basis for the optimal design of breakwaters, and further helping to improve the structural efficiency and economic benefits of breakwaters.

[0042] 3. The results of the present invention are helpful to design a breakwater structure that can effectively resist wave invasion and reduce the negative impact on the surrounding hydrodynamic environment. This is in line with the environmentally friendly design concept and helps to protect the sensitive coastal environment.

[0043] 5. The results of the present invention are helpful to evaluate the impact of pile-based hollow breakwaters on the overall regional ocean current environment of the project, provide important support for the safety protection and disaster prevention and mitigation of marine engineering, and further help reduce the occurrence of disasters such as coastal erosion, flooding and structure damage.

[0044] In summary, the solution of the present invention provides strong support for the optimal design of breakwaters, safety protection of marine engineering and disaster prevention and mitigation through a systematic study of the flow-blocking characteristics of pile-based hollow breakwaters. It also embodies an environmentally friendly design concept and has high scientific value and social significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a flow chart of the test method for testing the flow-blocking characteristics of the pile-based hollow breakwater according to the first embodiment;

[0046] Figure 2 Schematic diagram of the test environment in Example 1;

[0047] Figure 3 This is a schematic diagram of the pre-test section selected in Example 1;

[0048] Figure 4 A graph showing the change of the water level difference over time at each pre-test section in the pre-test in Example 1;

[0049] Figure 5 is a graph showing the flow velocity of each pre-test section changing with time in the pre-test in Example 1;

[0050] Figure 6 is the vertical flow velocity curve of each pre-test section in the pre-test in Example 1;

[0051] Figure 7 Schematic diagram of the points for measuring flow velocity using the three-point method in Example 1. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0053] Embodiment 1:

[0054] A test method for testing the flow-blocking characteristics of a pile-based permeable breakwater comprises the following steps:

[0055] S1: Determine the target sea area, collect the environmental factors of the target sea area, and determine the size of the test tank and the scale of the model according to the environmental factors of the target sea area.

[0056] In sea areas with different environmental factors, pile-foundation hollow breakwaters will exhibit different flow resistance characteristics. Therefore, before studying the flow resistance characteristics of pile-foundation hollow breakwaters, it is necessary to first determine the target sea area, and then study the flow resistance characteristics of pile-foundation hollow breakwaters in the target sea area.

[0057] S2: Configure the test water tank according to the size of the test water tank and the scale of the model, and set up a pile-foundation hollow breakwater model in the test water tank.

[0058] S3: According to the environmental factors of the target sea area and the model scale, the initial water depth and flow velocity are set for preliminary testing. After the flow field is stable, the vertical flow velocity distribution of multiple upstream and downstream preliminary test sections is obtained, the upstream and downstream water flow stable areas are determined, and a test section is selected in the upstream and downstream water flow stable areas respectively.

[0059] S4: According to the environmental factors of the target sea area and the model scale, set the initial water depth and flow velocity for characteristic test. After the flow field stabilizes, obtain the water depth and average flow velocity of the upstream test section and the downstream test section.

[0060] S5: Obtain the water depth and average flow velocity of the upstream and downstream test sections after the flow field is stabilized in the characteristic test experiment, and calculate the head loss and water flow resistance of the hydrodynamic field caused by the pile-based permeable breakwater model based on the energy equation and momentum equation.

[0061] The scheme of this embodiment is to determine the parameters of the target sea area and the test environment through S1, build the test environment according to the determined parameters of the test environment in S2, determine the test section for testing the flow resistance characteristics of the pile-based hollow breakwater in S3, perform tests in S4 and S5, obtain data of the test section, and calculate the head loss and water flow resistance, so as to determine the flow resistance characteristics of the pile-based hollow breakwater in the target sea area.

[0062] The solution of this embodiment sets up a test pile-based hollow breakwater model in a test environment, which fully considers the structural complexity of the pile-based hollow breakwater; during the test, it is only necessary to obtain the water depth and flow velocity, so it has a faster test efficiency and thus a shorter test time; after obtaining the water depth and flow velocity, the flow resistance characteristics of the pile-based hollow breakwater in the target sea area are determined based on the energy equation and the momentum equation, so the test results have higher accuracy and reliability.

[0063] Therefore, through the scheme of this embodiment, the influence mechanism of pile-based hollow breakwater on tides and nearshore currents can be revealed more accurately, which can be used to analyze the impact of breakwater on the evolution of the ocean current environment in the overall project area, thereby providing a scientific basis for the optimal design of the breakwater, which in turn helps to improve the structural efficiency and economic benefits of the breakwater.

[0064] In addition, the results of this embodiment are helpful to design a breakwater structure that can effectively resist wave invasion and reduce the negative impact on the surrounding hydrodynamic environment. This is in line with the environmentally friendly design concept and helps to protect the sensitive coastal environment.

[0065] On the other hand, the results of this embodiment are helpful to evaluate the impact of pile-based hollow breakwaters on the overall regional ocean current environment of the project, provide important support for the safety protection and disaster prevention and mitigation of marine engineering, and further help reduce the occurrence of disasters such as coastal erosion, flooding and structure damage.

[0066] In summary, the scheme of this embodiment provides strong support for the optimal design of breakwaters, safety protection and disaster prevention and mitigation of marine engineering through a systematic study of the flow-blocking characteristics of pile-based hollow breakwaters. It also embodies an environmentally friendly design concept and has high scientific value and social significance.

[0067] In an optional embodiment, the scale in S1 includes a length scale and a flow rate scale.

[0068] The length scale is the ratio of the water depth of the test flume to the water depth of the target sea area, as well as the ratio of the size of the pile-based hollow breakwater model in the test flume to the size of the real pile-based hollow breakwater. The flow velocity scale is the ratio of the flow velocity in the test flume to the flow velocity in the target sea area.

[0069] In an optional embodiment, S1 includes: S11: determining the target sea area, collecting the water depth and flow velocity of the target sea area, and calculating the Froude number of the target sea area; S12: configuring the size of the test water tank and determining the model scale so that the Froude number of the test environment and the Froude number of the target sea area meet the gravity similarity criterion.

[0070] During specific implementation, a test water tank can be re-established or an existing test water tank can be used as needed. When an existing test water tank is used, the model scale is set according to the size of the existing test water tank to ensure that the Froude number of the test environment and the Froude number of the target sea area meet the gravity similarity criterion, while ensuring that the water depth of the test water tank calculated according to the model scale and the size of the pile-based hollow breakwater model are within the size range of the test water tank.

[0071] In an optional embodiment, the pile-based hollow breakwater model in S2 includes: an upper open-hole wave-breaking structure and a lower supporting pile; the open-hole wave-breaking structure has an inwardly concave arc surface facing upstream and is provided with a plurality of through holes, and the open-hole wave-breaking structure has an inwardly vertical surface facing downstream and is provided with a through hole; there are at least two supporting piles, and the supporting piles are angular structures, and are provided with a plurality of through holes.

[0072] In this optional embodiment, the support piles are arranged on the bottom surface of the test water tank and used to support the wave-breaking structure with holes. The above-mentioned pile-based hollow breakwater model highly restores the structure of the actual pile-based hollow breakwater in the project, thereby making the flow resistance characteristics of the tested pile-based hollow breakwater more accurate and reliable.

[0073] In an optional embodiment, in S1, the environmental factors of the target sea area collected include water depth and flow velocity, and the determined model scale includes a length scale and a flow velocity scale; S3 includes the following steps: S31: according to the water depth and flow velocity of the target sea area, as well as the length scale and the flow velocity scale, set the initial water depth and flow velocity for preliminary testing; S32: select multiple preliminary testing sections in the upstream and downstream respectively, and continuously collect the water depth and flow velocity of each preliminary testing section, and judge the flow field according to the continuously collected water depth and flow velocity of each preliminary testing section Whether it is stable, execute S33 after the flow field is stable; S33: According to the water depth of each pre-test section, select several flow velocity collection points in the vertical direction of each pre-test section, and then collect the flow velocity at each flow velocity collection point in the vertical direction of each pre-test section, and then draw the vertical flow velocity curve of each pre-test section respectively; S34: According to the vertical flow velocity curve of each pre-test section, determine the upstream and downstream turbulent water flow areas and the stable water flow areas respectively, and then select a pre-test section in the upstream and downstream stable water flow areas as the test section.

[0074] During specific implementation, the test section can be selected from the pre-test sections, or other sections can be selected from the stable water flow area as the test section.

[0075] In this optional embodiment, different initial water depths and flow rates may be set to conduct multiple preliminary tests to select a test section.

[0076] In an optional embodiment, in S1, the environmental factors of the target sea area collected include water depth and flow velocity, and the determined model scale includes a length scale and a flow velocity scale; the S4 includes the following steps: S41: according to the water depth and flow velocity of the target sea area, as well as the length scale and the flow velocity scale, set the initial water depth and flow velocity for characteristic testing; S42: continuously collect the water depth and flow velocity of the upstream test section and the downstream test section, and judge whether the flow field is stable based on the continuously collected water depth and flow velocity of the upstream test section and the downstream test section, and execute S43 after the flow field is stable; S43: according to the water depth of the upstream test section and the downstream test section, select flow velocity collection points in the vertical direction of the upstream test section and the downstream test section respectively, and then collect the flow velocity at each flow velocity collection point in the vertical direction of the upstream test section and the downstream test section respectively, and then calculate the average flow velocity of the upstream test section and the downstream test section.

[0077] In an optional embodiment, the S43 includes the following steps: S431: according to the water depths of the upstream test section and the downstream test section, select the water depths of 0.2 times, 0.6 times and 0.8 times the water surface in the vertical direction of the upstream test section and the downstream test section as flow velocity collection points; S432: collect the flow velocity at each flow velocity collection point in the vertical direction of the upstream test section and the downstream test section, and calculate the average flow velocity of the upstream test section and the downstream test section according to the following formula:

[0078] ,

[0079] In the formula, U is the average flow velocity of the test section, and the subscripts 0.2, 0.6, and 0.8 represent the flow velocities at 0.2 times, 0.6 times, and 0.8 times the water depth from the water surface, respectively.

[0080] In an optional embodiment, in S5, based on the energy equation and the momentum equation, the following formulas are used to calculate the head loss between the upstream and downstream test sections caused by the pile-based hollow breakwater model and the comprehensive water flow resistance of the hydrodynamic field caused by the pile-based hollow breakwater model:

[0081] ,

[0082] ,

[0083] In the formula, △H is the head loss between the upstream and downstream test sections caused by the pile-based hollow breakwater model, U1 is the average flow velocity of the upstream test section, U2 is the average flow velocity of the upstream test section, h1 is the water depth of the upstream test section, h2 is the water depth of the upstream test section, g is the gravitational acceleration, ρ is the water density, B is the size of the pile-based hollow breakwater model in the width direction of the test water tank, and F is the comprehensive water flow resistance of the hydrodynamic field caused by the pile-based hollow breakwater model.

[0084] In this optional embodiment, different initial water depths and flow rates may be set to conduct preliminary tests to more comprehensively determine the flow resistance characteristics of the pile-based hollow breakwater in the target sea area.

[0085] The solution of this embodiment is further explained and illustrated by a specific implementation process below.

[0086] In S1, the Bohai coast is selected as the target sea area, and the water depth of the target sea area is 6.5-14 meters, and the flow rate is 1m / s; the size of the test flume is selected as 50 meters long, 0.6 meters wide, and 1.4 meters deep. Figure 2 As shown, the x direction is the length direction, and the z direction is the depth direction (i.e. vertical). On this basis, in order to comply with the principle of gravity similarity, that is, to ensure that the Froude number of the test environment is similar to that of the target sea area, the length ratio is finally determined to be 1:12, and the velocity ratio is the square root of the length ratio, that is, the velocity ratio is 1:3.46, and then the size of the pile-based hollow breakwater model set in the test water tank is determined to be 1.1 meters long, 0.6 meters wide, and 1.3 meters high.

[0087] In S2, a test water flume is set up, and a pile-foundation hollow breakwater model is set up; in addition, a water inlet is set up on a first side in the length direction of the test water flume (this side is the upstream), and a water outlet is set up on a second side (this side is the downstream), wherein the first side refers to a side of the inwardly concave arc surface of the open hole wave-breaking knot in the pile-foundation hollow breakwater model in the length direction of the test water flume, and the second side refers to a side opposite to the first side.

[0088] In S3, the midpoint of the length direction of the pile-based hollow breakwater model is taken as the zero point of the x direction in the test flume, as follows: Figure 3 As shown, six vertical sections of x=-6 times the dike length (the dike length refers to the length of the pile-based hollow breakwater model, i.e. 1.1 meters), -3 times the dike length, 3 times the dike length, 6 times the dike length, 9 times the dike length, and 12 times the dike length were selected as pre-test sections, i.e. two sections were selected upstream and four sections were selected downstream.

[0089] Thereafter, in S3, according to the water depth and flow velocity of the target sea area as well as the length scale and flow velocity scale, the initial water depth and flow velocity are set for preliminary testing, and then the water depth and flow velocity of each preliminary testing section are obtained; when obtaining the water depth, the initial water depth is first obtained, and then the water level difference is monitored in real time by the wave height meter, such as Figure 4 As shown, the two are combined to obtain the water depth; when obtaining the flow velocity, it is obtained through a flow meter, such as Figure 5 shown.

[0090] according to Figure 4 and Figure 5 It can be seen that the flow field stabilizes after 10 minutes. Subsequently, according to the water depth of each pre-test section, 0.8 times, 0.7 times, 0.6 times, 0.5 times, 0.4 times, 0.3 times, 0.2 times, 0.1 times, and 0.05 times the water depth from the water surface are used as flow velocity collection points. It should be understood that the water depth of each pre-test section is different after the flow field is stabilized, so each collection point is a relative height, not an absolute height.

[0091] Subsequently, shallow velocity meters were used to measure the flow velocity at each velocity collection point on each pre-test section, and the vertical velocity curves of each pre-test section were drawn, such as Figure 6 As shown, Figure 6 The ordinate is the relative height value, and the abscissa is the ratio of the flow velocity at each sampling point to the average flow velocity of the pre-experimental section. It can be seen that the upstream is a stable water flow area, the downstream 9-12 times the dike length is a stable water flow area, and the rest is a turbulent water flow area. Finally, 4 times the dike length upstream was selected as the upstream test section, and 10 times the dike length downstream was selected as the downstream test section.

[0092] In S4, characteristic test experiments were carried out with initial water depth of 0.95 m + initial flow velocity of 0.042 m / s, initial water depth of 0.95 m + initial flow velocity of 0.078 m / s, initial water depth of 0.95 m + initial flow velocity of 0.111 m / s, initial water depth of 0.95 m + initial flow velocity of 0.162 m / s, and initial water depth of 0.95 m + initial flow velocity of 0.218 m / s.

[0093] After the flow field is stable, the average flow velocity of the upstream test section and the downstream test section is calculated by the three-point method. The three-point method point positions are as follows: Figure 7 As shown in Table 1, the head loss and water flow resistance under each test condition are calculated.

[0094] Table 1 Hydrodynamic data record and calculation table of the special test section of pile-based hollow breakwater

[0095] Initial water depth (m) Initial flow rate (m / s) <![CDATA[Depth of water at the upstream cross-section h1 (m)]]> <![CDATA[Depth of water h2 (m) at the downstream cross-section]]> <![CDATA[Upstream cross-section flow velocity U1 (m / s)]]> <![CDATA[Downstream cross-section velocity U2 (m / s)]]> Head loss(m) Water flow resistance (N) 0.95 0.042 0.953 0.948 0.0417 0.0427 0.005 27.9 0.95 0.078 0.960 0.944 0.0784 0.0772 0.016 89.6 0.95 0.111 0.972 0.939 0.106 0.111 0.033 185.4 0.95 0.162 0.989 0.93 0.154 0.163 0.059 332.9 0.95 0.218 1.01 0.92 0.203 0.225 0.09 510.7

[0096] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A test method for testing the flow resistance characteristics of a pile-based permeable breakwater, characterized in that: The steps include: S1: Determine the target sea area, collect the environmental factors of the target sea area, and determine the size of the test tank and the scale of the model according to the environmental factors of the target sea area; S2: According to the size of the test water tank and the scale of the model, a test water tank is configured, and a pile-based hollow breakwater model is set in the test water tank; the pile-based hollow breakwater model includes: an upper open-hole wave-breaking structure and a lower support pile; the open-hole wave-breaking structure has an inwardly concave arc surface facing upstream and is provided with a plurality of through holes, and the open-hole wave-breaking structure has an inwardly vertical surface facing downstream and is provided with a through hole; there are at least two support piles, and the support piles are angular structures, and the support piles are provided with a plurality of through holes; S3: According to the environmental factors of the target sea area and the model scale, the initial water depth and flow velocity are set for preliminary testing. After the flow field is stable, the vertical flow velocity distribution of multiple upstream and downstream preliminary test sections is obtained, the upstream and downstream water flow stable areas are determined, and a test section is selected in the upstream and downstream water flow stable areas respectively; S4: According to the environmental factors of the target sea area and the model scale, set the initial water depth and flow velocity to conduct characteristic test. After the flow field is stable, obtain the water depth and average flow velocity of the upstream test section and the downstream test section; S5: Obtain the water depth and average flow velocity of the upstream and downstream test sections after the flow field obtained in the characteristic test is stabilized, and calculate the head loss and water flow resistance of the hydrodynamic field caused by the pile-based hollow breakwater model based on the energy equation and momentum equation; Based on the energy equation and momentum equation, the head loss between the upstream and downstream test sections caused by the pile-based hollow breakwater model and the comprehensive water flow resistance of the hydrodynamic field caused by the pile-based hollow breakwater model are calculated using the following formulas: ， ， In the formula, △H is the head loss between the upstream and downstream test sections caused by the pile-based hollow breakwater model, U1 is the average flow velocity of the upstream test section, U2 is the average flow velocity of the upstream test section, h1 is the water depth of the upstream test section, h2 is the water depth of the upstream test section, g is the gravitational acceleration, ρ is the water density, B is the size of the pile-based hollow breakwater model in the width direction of the test water tank, and F is the comprehensive water flow resistance of the hydrodynamic field caused by the pile-based hollow breakwater model.

2. A test method for testing the flow-blocking characteristics of a pile-based hollow breakwater according to claim 1, characterized in that: The scales in S1 include a length scale and a flow rate scale.

3. A test method for testing the flow resistance characteristics of a pile-based hollow breakwater according to claim 2, characterized in that: The S1 includes: S11: determine the target sea area, collect the water depth and flow velocity of the target sea area, and calculate the Froude number of the target sea area; S12: Configure the test tank size and determine the model scale so that the Froude number of the test environment and the Froude number of the target sea area meet the gravity similarity criterion.

4. A test method for testing the flow resistance characteristics of a pile-based hollow breakwater according to claim 1, characterized in that: In S1, the environmental factors collected in the target sea area include water depth and current velocity, and the model scales determined include length scale and current velocity scale; The S3 comprises the following steps: S31: According to the water depth and flow velocity of the target sea area, as well as the length scale and flow velocity scale, set the initial water depth and flow velocity for preliminary testing; S32: Select multiple pre-test sections at the upstream and downstream, and continuously collect the water depth and flow velocity of each pre-test section, and judge whether the flow field is stable according to the continuously collected water depth and flow velocity of each pre-test section, and execute S33 after the flow field is stable; S33: according to the water depth of each pre-test section, select a number of flow velocity collection points in the vertical direction of each pre-test section, and then respectively collect the flow velocity at each flow velocity collection point in the vertical direction of each pre-test section, and then respectively draw the vertical flow velocity curve of each pre-test section; S34: Determine the upstream and downstream water turbulence areas and water smooth areas according to the vertical flow velocity curves of each pre-test section, and then select a pre-test section in the upstream and downstream water smooth areas as the test section.

5. A test method for testing the flow resistance characteristics of a pile-based hollow breakwater according to claim 1, characterized in that: In S1, the environmental factors collected in the target sea area include water depth and current velocity, and the model scales determined include length scale and current velocity scale; The S4 comprises the following steps: S41: According to the water depth and flow velocity of the target sea area, as well as the length scale and flow velocity scale, set the initial water depth and flow velocity to conduct characteristic test; S42: continuously collecting the water depth and flow velocity of the upstream test section and the downstream test section, and judging whether the flow field is stable according to the continuously collected water depth and flow velocity of the upstream test section and the downstream test section, and executing S43 after the flow field is stable; S43: According to the water depths of the upstream test section and the downstream test section, flow velocity collection points are selected in the vertical direction of the upstream test section and the downstream test section respectively, and then the flow velocities at each flow velocity collection point in the vertical direction of the upstream test section and the downstream test section are collected respectively, and then the average flow velocities of the upstream test section and the downstream test section are calculated.

6. A test method for testing the flow-blocking characteristics of a pile-based hollow breakwater according to claim 5, characterized in that: The S43 comprises the following steps: S431: According to the water depths of the upstream test section and the downstream test section, the water depths of 0.2 times, 0.6 times and 0.8 times from the water surface in the vertical direction of the upstream test section and the downstream test section are selected as flow velocity collection points; S432: Collect the flow velocities at each flow velocity collection point in the vertical direction of the upstream test section and the downstream test section respectively, and calculate the average flow velocities of the upstream test section and the downstream test section according to the following formula: ， In the formula, U is the average flow velocity of the test section, and the subscripts 0.2, 0.6, and 0.8 represent the flow velocities at 0.2 times, 0.6 times, and 0.8 times the water depth from the water surface, respectively.

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