Design method and system for cofferdam drainage port in tidal river channel project and related equipment

Abstract

The invention discloses a design method and system for a cofferdam drainage port in a tidal river channel project and related equipment, according to the scheme, on the basis of hydrodynamic simulation, a water head loss calculation method of the drainage port is further innovatively fused, and therefore in tidal river channel hydrodynamic simulation, the water head loss of the drainage port can be calculated. And engineering scene simulation after the cofferdam is additionally provided with the drainage port is formed, so that parameters such as water flow characteristics, a cofferdam structure and the size of the drainage port can be effectively introduced on the basis, and the design scheme of the drainage port, such as the number and the size, can be accurately determined.

Description

Technical Field

[0001] The invention relates to the field of water conservancy projects, in particular to a design method for a cofferdam spillway in a tidal river project. Background Art

[0002] In tidal river projects, cofferdams are temporary water retaining structures and are often used for dry land operations during construction. However, in rivers with significant tidal influences, the construction of cofferdams often has a significant constriction effect on the surrounding water flow, resulting in water level rise and increased flow velocity, posing potential risks to project safety and the surrounding environment. To address this issue, for cofferdams with trail-like properties, a certain diameter of spillway is often set at the bottom of the cofferdam to divert flow, so that the water level rise and increased flow velocity in the constricted river channel are alleviated.

[0003] At present, in tidal river projects, the design of the diameter of the concrete pipe buried at the bottom of the cofferdam mainly relies on the traditional semi-empirical weir flow formula to calculate the design. This makes the design less accurate, so at this stage, a more conservative strategy is usually adopted for the design of the cofferdam spillway, that is, to increase the calculated size empirically, and try to ensure that the discharge flow in real conditions can meet the engineering design, but the accuracy of the design parameters cannot be guaranteed.

[0004] Therefore, the existing design method of the cofferdam spillway is still lacking in scientificity and systematicity, and lacks in-depth analysis and accurate simulation of water flow characteristics when the spillway is set up on the earth cofferdam, resulting in inaccurate design parameters of the spillway and inability to effectively guide the construction of the project. This not only affects the control of project costs, but also hides the safety risks of the project. Summary of the invention

[0005] In view of the problem of inaccurate design parameters in the design scheme of cofferdam spillways in existing tidal river channel projects, the purpose of the present invention is to provide a design scheme for cofferdam spillways in tidal river channel projects, which can accurately determine the spillway design scheme by organically integrating various parameters such as water flow characteristics, cofferdam structure, and spillway size, thereby effectively overcoming the problems existing in the prior art.

[0006] In order to achieve the above object, the present invention provides a design method for a cofferdam spillway in a tidal river project, comprising:

[0007] Construct a hydrodynamic model for the cofferdam in the target tidal river project;

[0008] Incorporating a hydrodynamic calculation sub-model of the spillway into the hydrodynamic model to calculate and determine the head loss of the spillway;

[0009] According to different cofferdam spillway design schemes, based on the improved hydrodynamic model integrated with the hydrodynamic calculation sub-model, an engineering scenario simulation after adding spillway to the cofferdam is formed in the hydrodynamic simulation of the tidal river channel. The flow field and water level changes before and after the project are observed, and the final design scheme is evaluated and determined.

[0010] In some embodiments of the present invention, a hydrodynamic module is constructed based on the Navier-Stokes equations in the design method.

[0011] In some embodiments of the present invention, a triangular grid is used in the horizontal direction in the hydrodynamic module constructed in the design method, and a 2D model of vertical depth and water average is used for the case where the water depth of the tidal river is shallow.

[0012] In some embodiments of the present invention, the hydrodynamic calculation submodel in the design method can introduce the head loss of the calculated spillway into the hydrodynamic model, and convert the pressure item in the hydrodynamic model when there is no spillway into the water level pressure loss according to the head loss, and correct the deviation of the water level pressure item in the hydrodynamic model accordingly.

[0013] In order to achieve the above object, the present invention provides a design system for a cofferdam spillway in a tidal river project, comprising:

[0014] A model building module, wherein the model building module is configured to build a hydrodynamic model for a cofferdam in a target tidal river project;

[0015] A spillway head loss calculation module, wherein the spillway head loss calculation module is configured to perform data interaction with the model building module, and is capable of integrating a hydrodynamic calculation sub-model of the spillway into the hydrodynamic model to calculate and determine the head loss of the spillway;

[0016] A scheme confirmation module is configured to interact with the model construction module and the spillway head loss calculation module for data, and can design schemes for different cofferdam spillways, based on an improved hydrodynamic model that incorporates a hydrodynamic calculation sub-model, to form an engineering scenario simulation after the cofferdam is added with a spillway in the hydrodynamic simulation of a tidal river.

[0017] In some embodiments of the present invention, the model building module builds a hydrodynamic module based on the Navier-Stokes equations.

[0018] In some embodiments of the present invention, a triangular grid is used in the horizontal direction in the hydrodynamic module, and for a tidal river with a shallow water depth, a 2D model with vertical depth and water average is used.

[0019] In some embodiments of the present invention, the spillway head loss calculation module is configured to introduce the head loss of the spillway determined by the hydrodynamic calculation submodel into the hydrodynamic model, and convert the pressure item in the hydrodynamic model when there is no spillway into the water level pressure loss according to the head loss, and correct the water level pressure item deviation in the hydrodynamic model accordingly.

[0020] In order to achieve the above object, the present invention also provides a computer-readable storage medium having a program stored thereon, which, when executed by a processor, implements the steps of the design method of the cofferdam spillway in the tidal river project.

[0021] In order to achieve the above object, the present invention further provides a processor, which is used to run a program, and when the program is run, the steps of the design method of the cofferdam spillway in the tidal river project are executed.

[0022] In order to achieve the above-mentioned purpose, the present invention also provides a terminal device, which includes a processor, a memory, and a program stored in the memory and executable on the processor, wherein the program code is loaded and executed by the processor to implement the steps of the design method of the cofferdam spillway in the above-mentioned tidal river project.

[0023] In order to achieve the above object, the present invention also provides a computer program product, which, when executed on a data processing device, is suitable for executing the steps of the above-mentioned method for designing a cofferdam spillway in a tidal river project.

[0024] The design scheme of cofferdam spillway in tidal river channel engineering provided by the present invention innovatively incorporates a head loss calculation model of the spillway on the basis of hydrodynamic simulation, so as to realize the simulation of engineering scenarios after effectively adding cofferdams and spillway in the hydrodynamic simulation of tidal river channel, and further introduces various parameters such as water flow characteristics, cofferdam structure, and spillway size, so as to scientifically and accurately determine the design scheme of the spillway, such as the number and size.

[0025] The design scheme of the spillway of the cofferdam in the tidal river project provided by the present invention adopts an improved numerical simulation model to accurately simulate and analyze the water flow field before and after the spillway is added to the cofferdam, and can provide a scientific and accurate parameter basis for the design of the spillway.

[0026] The design scheme of the cofferdam spillway in the tidal channel project provided by the present invention can significantly improve the scientificity and rationality of the design of the cofferdam spillway in the tidal channel project when applied specifically, reduce the project cost and safety risk, and has important practical significance and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0028] Figure 1 It is a flow chart for implementing the design of the cofferdam spillway in the tidal river project in the example of the present invention;

[0029] Figure 2 This is an example diagram of the location of the river bank construction area in the clean water project in the example of the present invention;

[0030] Figure 3 It is an example diagram of the plan layout of the earth cofferdam access road in the example of the present invention;

[0031] Figure 4 This is an example diagram of a hydrodynamic calculation model grid in an example of the present invention;

[0032] Figure 5 This is an example diagram of the flow field distribution near the engineering area before the engineering in the example of the present invention;

[0033] Figure 6 This is an example diagram of the flow field distribution near the engineering area after the engineering in the example of the present invention;

[0034] Figure 7 This is a graph showing the changes in tide level and flow velocity over time near the project area during high tides before and after the project in an example of the present invention. DETAILED DESCRIPTION

[0035] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below with reference to specific diagrams.

[0036] In view of the problems and defects of the existing design scheme of cofferdam spillways in tidal river projects based on the traditional semi-empirical weir flow formula, the present invention proposes a design scheme of cofferdam spillways in tidal river projects. On the basis of hydrodynamic simulation, the scheme further innovates the head loss calculation method of spillways, thereby realizing the engineering scenario simulation after the cofferdam is formed and spillways are added in the hydrodynamic simulation of tidal rivers, so that on this basis, parameters such as water flow characteristics, cofferdam structure, and spillway size can be effectively introduced, thereby realizing the accurate determination of the number and size of the spillways.

[0037] Based on this, the present invention provides a design method for a cofferdam spillway in a tidal river project. The entire design method mainly consists of the following three parts.

[0038] This design scheme first constructs a hydrodynamic model for the cofferdam in the target tidal river project to simulate the changes in the flow field before and after the target project.

[0039] On this basis, this design scheme further incorporates the hydrodynamic calculation sub-model of the spillway into the constructed hydrodynamic model. The hydrodynamic calculation sub-model can introduce the cross-sectional area and spillway size parameter characteristics to calculate and determine the head loss of the spillway. The head loss here specifically refers to the mechanical energy loss caused by factors such as fluid viscosity and local flow resistance. In this scheme, after calculating and determining the accurate value of the head loss △H through the hydrodynamic calculation sub-model, the accurate value of the pressure term η of the spillway in the hydrodynamic model is further calculated based on the calculated accurate value of the head loss.

[0040] Therefore, during the simulation operation, the hydrodynamic model can convert the pressure term η in the hydrodynamic model when there is no discharge port into water level pressure loss according to the head loss value △H, and then consider this water level pressure loss as an additional pressure boundary condition or as a volume force, so as to determine the real water level term η=η-ΔH.

[0041] Furthermore, based on the improved hydrodynamic model that incorporates the hydrodynamic calculation of the spillway, it is possible to form an engineering scenario simulation after the cofferdam is added with a spillway in the hydrodynamic simulation of the tidal river.

[0042] Finally, the design scheme of the cofferdam spillway is determined based on the improved hydrodynamic model that incorporates the spillway hydrodynamic calculation.

[0043] That is, by comparing the simulation results of engineering scenarios under different spillway sizes and numbers (such as flow field and water level changes), analyzing their impact on the water level rise and flow velocity increase in the engineering area, and selecting the scheme that meets the engineering requirements (such as water level rise and flow velocity increase not exceeding a certain proportion) as the final cofferdam spillway design scheme.

[0044] As a further explanation, the design method provided by the present invention uses a hydrodynamic numerical simulation method to simulate the changes in the flow field before and after the project when constructing a hydrodynamic model for a cofferdam in a target tidal river project.

[0045] When constructing a hydrodynamic model for a cofferdam in a target tidal channel project, the solution of the present invention first determines and introduces data and parameters related to the cofferdam in the target tidal channel project in the hydrodynamic model, which mainly include data related to water flow characteristics, data related to the cofferdam structure, and data related to the size of the spillway.

[0046] Water flow characteristic related data, specifically, data used to describe the basic motion state and characteristics of water flow; the introduction of water flow characteristic related data can be used to build a hydrodynamic model. The water flow characteristic related data specifically include: water level (η), water depth (h), vertical average and x, y direction flow velocity (u, v), gravitational acceleration (g), dimensionless friction coefficient, Manning coefficient (n), horizontal eddy viscosity coefficient, Coriolis force coefficient, etc.

[0047] The introduction of cofferdam structure-related data is used to determine the narrowing effect of the cofferdam on the water flow and the boundary conditions when building the hydrodynamic model. The cofferdam structure-related data specifically includes: the location, shape, size and other information of the cofferdam.

[0048] The introduction of orifice size-related data is used to calculate the head loss of the discharge port. The orifice size-related data specifically includes: the length (L) of the discharge port, the diameter (used to calculate the average cross-sectional area A s ), inlet and outlet cross-sectional areas (A1 and A2), etc. The head loss calculation results of the discharge port involved here include the total head loss, which is calculated by the inlet or contraction loss, outlet or expansion loss, friction loss and elbow loss coefficient. The total head loss can effectively reflect the energy loss under various local losses and friction conditions.

[0049] Next, a hydrodynamic model is constructed based on the introduced data and parameters.

[0050] Here, the hydrodynamic numerical simulation method is preferably used, and a triangular grid is used in the horizontal direction. For the case of shallow water in tidal rivers, a 2D model with vertical depth and water average can be used. The mathematical model in the hydrodynamic module is constructed based on the Navier-Stokes equation. By integrating the three-dimensional horizontal momentum equation and the continuity equation along the water depth and ignoring the vertical difference of the water body, a two-dimensional shallow water equation is obtained.

[0051] At the same time, the Manning coefficient is used to calculate the bottom friction, and the ADI method is used to jointly solve the momentum conservation equation and the continuity equation to obtain the hydrodynamic field for each time step. The time step △t is determined by the CFL number.

[0052] As a further explanation, when constructing the mathematical model in the hydrodynamic module based on the Navier-Stokes equation, the present invention specifically integrates the three-dimensional horizontal momentum equation and the continuity equation along the water depth while ignoring the vertical difference of the water body to obtain the following two-dimensional shallow water equation:

[0053]

[0054] where c f Calculated using the Manning coefficient:

[0055]

[0056] Where η is the water level (m); h is the water depth (m); u and v are the vertical average x and y flow velocities (m / s); g is the gravitational acceleration (m / s 2 );c f is the dimensionless friction coefficient; n is the Manning coefficient (s / m 1 / 3 );v His the horizontal eddy viscosity coefficient (m 2 / s); f is the Coriolis force coefficient (1 / s); M x 、M y are the external momentum sources and sinks in the x and y directions (m / s 2 ).

[0057] Furthermore, the solution of the present invention adopts the ADI method (Alternating Direction Implicit method) to jointly solve the momentum conservation equation and the continuity equation to obtain the hydrodynamic field of each time step.

[0058] The time step Δt is usually determined by the CFL number (Courant-Friedrichs-Lewy number):

[0059]

[0060] Where Δx and Δy are the minimum grid sizes in the x and y directions.

[0061] As a further explanation, the head loss involved in the solution of the present invention specifically refers to the energy loss caused by friction, local resistance, etc. when water flows through a pipe, channel or other flow channel in hydraulics.

[0062] Based on the above-mentioned hydrodynamic model construction scheme, the hydrodynamic calculation sub-model provided by the present invention is specifically constructed by the following formula (2.6), thereby being able to accurately determine the total head loss △H of the spillway.

[0063]

[0064] Where As is the average cross-sectional area over the length of the orifice, Q is the flow rate, z1 is the inlet or contraction loss, z2 is the outlet or expansion loss, zf is the friction loss calculated using Manning's formula, and zb is the elbow loss coefficient.

[0065] Furthermore, the inlet and outlet loss coefficients in the hydrodynamic calculation submodel can be specifically calculated based on the inlet and outlet cross-sectional areas.

[0066] Specifically, the inlet or contraction loss z1 and the outlet or expansion loss z2 are determined by the following formulas (2.7) and (2.8), respectively:

[0067]

[0068] Among them, A1 and A2 are the inlet and outlet cross-sectional areas respectively, zin and zout are the inflow and outflow loss coefficients respectively.

[0069] Furthermore, the friction loss in the hydrodynamic calculation submodel can be calculated based on the length of the discharge port, the Manning coefficient and the average hydraulic radius of the discharge port.

[0070] Specifically, the friction loss zf calculated using the Manning formula is determined by the following formula (2.9):

[0071]

[0072] Where L is the length of the outlet, n is the Manning coefficient, and R is the average hydraulic radius of the outlet. The Manning n value depends on the inner surface of the outlet. The n value for concrete outlets is usually between 0.011 and 0.017.

[0073] Furthermore, the elbow loss coefficient zb is used to represent other head loss conditions other than the above, such as elbows, damaged culverts, trapped debris, etc.

[0074] The hydrodynamic calculation sub-model constructed in this way can effectively introduce friction loss, cross-sectional area and discharge port size, local loss at the inlet and outlet, and elbow loss parameter characteristics to calculate and determine the head loss at the discharge port, which can more comprehensively reflect the actual energy loss at the discharge port. At the same time, by integrating the hydrodynamic calculation sub-model with the constructed hydrodynamic module, after calculating and determining the head loss based on the hydrodynamic calculation sub-model, the accurate value of the calculated head loss △H can be introduced to determine the pressure term of the discharge port in the Navier-Stokes equation in the hydrodynamic module. η In this way, the discharge port can be used in the numerical solution of the Navier-Stokes equations to obtain the original state without the discharge port. η The head loss △H is converted into water level pressure loss (i.e., the deviation of the water level pressure term in the existing NS equation is corrected), and then this water level pressure loss is used as an additional pressure boundary condition or as a volume force and integrated into the Navier-Stokes equation water level term η=η-ΔH for a real solution.

[0075] The hydrodynamic calculation sub-model formed based on this can more accurately calculate the total head loss at the spillway because it comprehensively considers various physical factors and local structural factors. For different spillway sizes and river flow characteristics, this sub-model can give more realistic head loss values ​​based on specific parameters, avoiding the large errors that may be caused by simple empirical formulas in the past, and providing a more accurate data basis for subsequent calculations such as substituting head loss into the Navier-Stokes equation.

[0076] Furthermore, each loss calculation performed by the hydrodynamic calculation sub-model is associated with the actual size of the spillway (such as length, diameter, etc.) and related engineering material properties (such as the Manning coefficient), so that the calculation results are more consistent with the actual engineering situation.

[0077] Furthermore, this hydrodynamic calculation sub-model can accurately calculate the head loss, so that in the subsequent engineering scenario simulation, the impact of different spillway design schemes on water flow can be more accurately evaluated. For example, in the hydrodynamic simulation of tidal rivers, accurate head loss calculation helps to analyze the water level rise and flow velocity increase under different spillway sizes and numbers, thereby providing a scientific basis for selecting the optimal spillway design scheme, which is conducive to optimizing the design of cofferdam spillways, avoiding over-design or under-design, and effectively controlling engineering costs and reducing engineering risks.

[0078] Furthermore, after being integrated with the hydrodynamic module, this hydrodynamic calculation sub-model can effectively improve the authenticity of the simulation, and can achieve a more realistic simulation of tidal channel engineering scenes, reflecting the actual state of water flow when there are cofferdams and spillways. Through the precise calculation of the total head loss and the accurate solution of the hydrodynamic field, the entire hydrodynamic calculation sub-model can present a water flow field that is more in line with the actual situation, providing engineering personnel with simulation results that are closer to reality, which is helpful to predict and evaluate the impact of engineering construction on water flow in advance, and has better guiding significance for the design and implementation of tidal channel engineering.

[0079] Furthermore, after being integrated with the hydrodynamic module, this hydrodynamic calculation sub-model can systematically evaluate and compare different spillway design schemes. Since it can accurately calculate the head loss and water flow state under different conditions, it can quantitatively compare various possible design schemes (such as different pipe diameters and different numbers of spillways) to find the best solution that meets the engineering requirements (such as water level rise and flow rate increase not exceeding a certain proportion), improve the scientificity and systematicness of engineering design, and avoid the limitations of previous design methods based on semi-empirical formulas.

[0080] As a further explanation, when determining the final design scheme, the scheme of the present invention is mainly composed of a data preparation stage, a hydrodynamic model construction stage, a scheme comparison stage and a scheme determination stage in sequence.

[0081] Data preparation stage:

[0082] In this phase, data such as water flow characteristics, cofferdam structure data, and spillway size data are accurately obtained for the target project.

[0083] Among them, water flow characteristic data: collect information such as water level, water depth, vertical average and flow velocity in x and y directions, gravity acceleration, dimensionless friction coefficient, Manning coefficient, horizontal eddy viscosity coefficient, Coriolis force coefficient, etc. of tidal river channels. These data will serve as the basic input for constructing the hydrodynamic model, reflecting the basic water flow characteristics of tidal river channels.

[0084] Cofferdam structure data: clarify the location, shape, size and other information of the cofferdam in order to determine the narrowing effect and boundary conditions of the cofferdam on the water flow.

[0085] Outfall Dimensions: Measure and determine the outfall length, diameter (used to calculate average cross-sectional area), inlet and outlet cross-sectional areas, and other parameters. These data are critical to accurately calculate the head loss of the outfall.

[0086] Hydrodynamic model building phase:

[0087] (1) Construction of basic hydrodynamic model:

[0088] Based on the data collected in the data preparation stage, the mathematical model in the hydrodynamic module is constructed based on the Navier-Stokes equation. For the case of shallow water in tidal channels, the two-dimensional shallow water equation is obtained by integrating the three-dimensional horizontal momentum equation and continuity equation along the water depth while ignoring the vertical difference of the water body.

[0089] (2) Incorporate the hydrodynamic calculation sub-model to calculate the head loss at the spillway:

[0090] The hydrodynamic calculation submodel of the discharge port is integrated into the hydrodynamic model constructed in step (1) to calculate the total head loss of the discharge port. The composition of the hydrodynamic calculation submodel includes the calculation of the inlet or contraction loss, outlet or expansion loss, friction loss and elbow loss coefficient.

[0091] Solution comparison stage:

[0092] (1) Set up multi-scheme settings:

[0093] Set different combinations of discharge port sizes and quantities as different calculation schemes.

[0094] (2) Engineering scenario simulation:

[0095] For each calculation example, the calculated head loss is substituted into the hydrodynamic model based on the model constructed in the hydrodynamic model construction phase. The pressure term in the original state without a spillway is converted into water level pressure loss according to the head loss, and substituted into the water level term of the Navier-Stokes equation as an additional pressure boundary condition for a real solution, thus forming an engineering scenario simulation after the cofferdam has added spillways of different examples.

[0096] (3) Perform hydrodynamic simulation for each calculation scheme, observe the flow field and water level changes before and after the project, including comparing the flow field distribution near the project area before the project and after the project, and record the maximum flow velocity, water level rise and other indicators. At the same time, compare the changes in tide level and flow velocity at points in the project area under different schemes. These data will serve as the basis for evaluating the advantages and disadvantages of different schemes.

[0097] Solution determination stage:

[0098] (1) Evaluation criteria:

[0099] According to pre-set project requirements, for example, setting the water level rise and flow rate increase not exceeding a certain proportion (such as the water level rise and flow rate increase not exceeding a certain amount in the river channel before construction, or the water level rise and flow rate increase in the project area not exceeding a certain amount, etc.) as the evaluation standard.

[0100] (2) Solution screening:

[0101] By comparing the simulation results of different calculation schemes in the scheme comparison stage, the impact of each scheme on the water level rise and flow velocity increase in the project area is analyzed, and the scheme that meets the above evaluation criteria is selected as the final cofferdam spillway design scheme.

[0102] Compared with the conventional technology which lacks a better quantitative determination when substituting the head loss generated by the spillway into the water level pressure loss term in the NS equation, the solution of the present invention innovatively incorporates the head loss generated by the spillway when constructing the hydrodynamic model, and provides a calculation method for quantitatively substituting the head loss into the water level pressure loss term in the Navier-Stokes equation, thereby correcting the deviation of the water level pressure term in the existing NS equation and being able to more accurately consider the impact of energy loss on the water flow.

[0103] In this way, the design scheme of the cofferdam spillway in the tidal river project provided by the present invention can form accurate design parameters for the cofferdam spillway by adopting the improved numerical simulation technology to accurately simulate and analyze the water flow field before and after the spillway is added to the cofferdam, thereby providing a scientific basis for the design of the spillway.

[0104] Compared with the existing conventional technology, the design scheme of the cofferdam spillway in the tidal river project provided by the present invention has the following technical characteristics:

[0105] (1) Comprehensive consideration of multiple head loss factors: When constructing the hydrodynamic module and hydrodynamic calculation sub-model in the scheme of the present invention, not only common friction loss parameters are introduced, but also local losses at the inlet and outlet and other possible losses such as elbow losses are fully considered. Through the comprehensive calculation of these different types of head losses, the consideration of water flow energy loss is more comprehensive and more in line with the complex energy loss at the discharge port in actual engineering scenarios; compared with the existing conventional technology that simply considers part of the head loss or adopts empirical estimation, the final result determined by the scheme of the present invention is more systematic and accurate.

[0106] (2) Calculation based on actual engineering parameters: The calculations of the hydrodynamic module in the solution of the present invention are closely related to the actual engineering parameters, such as the actual size of the discharge port (length, diameter, inlet and outlet cross-sectional areas, etc.) and related engineering material properties (such as the Manning coefficient). This allows the power module to be adjusted according to specific engineering conditions, avoiding errors that may be caused by incomplete parameter considerations in traditional technologies, and improving the applicability and accuracy of the model.

[0107] (3) Based on numerical simulation and grid division: The hydrodynamic module in the solution of the present invention specifically adopts a hydrodynamic numerical simulation method, using a triangular grid in the horizontal direction. For shallow tidal channels, a 2D model with vertical depth and water average is used. This grid division method combined with numerical simulation is more suitable for the characteristics of tidal channel water flow. Compared with the conventional possible simple average or rough division, it can more accurately simulate the water flow movement state of tidal channels.

[0108] (4) Combining multiple equations and calculation methods: The hydrodynamic module in the scheme of the present invention specifically obtains a two-dimensional shallow water equation by integrating the three-dimensional horizontal momentum equation and the continuity equation along the water depth and ignoring the vertical difference of the water body, uses the Manning coefficient to calculate the bottom friction, and uses the ADI method to jointly solve the momentum conservation equation and the continuity equation to obtain the hydrodynamic field of each time step, and the time step is determined by the CFL number. The organic coordination and comprehensive use of multiple schemes can achieve a more accurate hydrodynamic field simulation compared to the conventional possible single calculation or rough equation solution.

[0109] Compared with the existing conventional technology, the design scheme of the cofferdam spillway in the tidal river project provided by the present invention has the following technical effects when applied:

[0110] (1) It can simulate the hydrodynamic field of tidal channels more accurately, especially considering the water flow state in the presence of cofferdams and spillways. By more accurately calculating the head loss and taking it into account, the simulation results are closer to the actual engineering scenario, which helps to improve the scientificity and rationality of the cofferdam spillway design.

[0111] (2) Since multiple factors are taken into comprehensive consideration, more accurate design parameters can be provided for the final cofferdam spillway design, overcoming the problem of inaccurate design parameters caused by semi-empirical formulas in traditional technologies. This can better control engineering costs and reduce engineering safety risks caused by unreasonable design.

[0112] (3) Different cofferdam spillway design schemes can be compared and analyzed more effectively. For example, by setting spillways of different pipe diameters and numbers as different calculation schemes, the hydrodynamic module can be used for simulation comparison to select the optimal scheme, making the design more systematic and scientific, rather than adopting a more conservative strategy like traditional technology and increasing the calculation size based on experience.

[0113] The design method of the cofferdam spillway in the tidal channel project provided by the solution of the present invention can constitute a corresponding software program in specific application, forming a corresponding design system of the cofferdam spillway in the tidal channel project. When the software program is running, it will execute the above-mentioned design method of the cofferdam spillway in the tidal channel project, and store it in the corresponding storage medium for the processor to call and execute.

[0114] The design system of the cofferdam spillway in the tidal river project thus formed is mainly composed of three modules: model construction module, spillway head loss calculation module and scheme confirmation module.

[0115] Among them, the model building module in the system is configured to be able to build a hydrodynamic model for the cofferdam in the target tidal river project.

[0116] The spillway head loss calculation module in the system is configured to perform data interaction with the model building module, and can integrate the spillway hydrodynamic calculation sub-model into the hydrodynamic model to calculate and determine the spillway head loss;

[0117] The scheme confirmation module in the system is configured to interact with the model construction module and the spillway head loss calculation module for data. It can construct different calculation schemes and simulate the engineering scenario for each calculation scheme based on the improved hydrodynamic model that incorporates the hydrodynamic calculation sub-model to obtain the engineering scenario under different spillway configurations. By comparing the simulation results of different calculation schemes, the scheme that meets the requirements is selected as the final cofferdam spillway design scheme.

[0118] As a further explanation, based on the above basic scheme, the model construction module in the design system of the cofferdam spillway in this tidal river project specifically constructs a hydrodynamic module based on the Navier-Stokes equation.

[0119] The specific implementation scheme is constructed based on the scheme shown in the above formulas (2.1) to (2.5).

[0120] As a further explanation, the spillway head loss calculation module in the design system of the cofferdam spillway in this tidal river project is specifically constructed by the following formula (2.6), which can accurately determine the total head loss △H of the spillway.

[0121]

[0122] Where As is the average cross-sectional area over the length of the orifice, Q is the flow rate, z1 is the inlet or contraction loss, z2 is the outlet or expansion loss, zf is the friction loss calculated using Manning's formula, and zb is the elbow loss coefficient.

[0123] Furthermore, the inlet and outlet loss coefficients in the hydrodynamic calculation submodel can be specifically calculated based on the inlet and outlet cross-sectional areas.

[0124] Specifically, the inlet or contraction loss z1 and the outlet or expansion loss z2 are determined by the following formulas (2.7) and (2.8), respectively:

[0125]

[0126] Among them, A1 and A2 are the inlet and outlet cross-sectional areas respectively, zin and zout are the inflow and outflow loss coefficients respectively.

[0127] Furthermore, the friction loss in the hydrodynamic calculation submodel can be calculated based on the length of the discharge port, the Manning coefficient and the average hydraulic radius of the discharge port.

[0128] Specifically, the friction loss zf calculated using the Manning formula is determined by the following formula (2.9):

[0129]

[0130] Where L is the length of the outlet, n is the Manning coefficient, and R is the average hydraulic radius of the outlet. The Manning n value depends on the inner surface of the outlet. The n value for concrete outlets is usually between 0.011 and 0.017.

[0131] Furthermore, the elbow loss coefficient zb is used to represent other head loss conditions other than the above, such as elbows, damaged culverts, trapped debris, etc.

[0132] On this basis, the head loss calculation module of the spillway can integrate the constructed hydrodynamic calculation sub-model with the hydrodynamic module, and be configured to introduce the calculated accurate value of the head loss △H to determine the pressure term of the spillway in the Navier-Stokes equation in the hydrodynamic module after the head loss is calculated based on the hydrodynamic calculation sub-model. ηThe exact value is that in the numerical solution of the Navier-Stokes equation, the original state without a discharge port can be η The head loss △H is converted into water level pressure loss (i.e., the deviation of the water level pressure term in the existing NS equation is corrected), and then this water level pressure loss is used as an additional pressure boundary condition or as a volume force and integrated into the Navier-Stokes equation water level term η=η-ΔH for a real solution.

[0133] In order to further illustrate the design scheme of the cofferdam spillway in the tidal river project provided by the present invention, the application implementation process and corresponding technical features of the scheme of the present invention are explained below through specific application examples.

[0134] This example takes the need to add an earthen cofferdam trail project in a tidal river section of a certain river as an example. In this example, the cofferdam spillway design system in the corresponding tidal river project is first constructed. The specific composition scheme is as mentioned above and will not be repeated here.

[0135] like Figure 1 As shown, the specific implementation steps for designing and determining the corresponding parameters of the cofferdam spillway in the tidal river section where an earth cofferdam trail is required are as follows:

[0136] Step (1) Data collection of tidal river sections.

[0137] See also Figure 2 , which shows the location map of the river bank construction area in the clean water project involved in this example. In this regard, this step first collects the river bank, boundary position, topographic data and hydrodynamic data of the river.

[0138] Step (2) Collection of construction data.

[0139] See also Figure 3 The main structural design of the access road and platform in the earth cofferdam trail project in the tidal river section involved in this example is as follows: the top surface elevation of the access road and platform is 3m; the access road is backfilled with slag or concrete blocks, the road surface width is 6m, the slope on both sides is 1:1.5, and the access road length is 35m; after the construction is completed at the bottom 2m, a diameter concrete pipe is placed for drainage.

[0140] On the foundation, in order to ensure that the rising water level and flow rate do not exceed 40% of the river channel before construction, it is necessary to determine the diameter and number of concrete spillways to be laid at the bottom.

[0141] Based on step (1) and step (2), the following data are collected:

[0142] Data related to water flow characteristics: including water level (η), water depth (h), vertical average and flow velocity in the x and y directions (u, v), gravitational acceleration (g), dimensionless friction coefficient, Manning coefficient (n), horizontal eddy viscosity coefficient, Coriolis force coefficient, etc.

[0143] Data related to the cofferdam structure: location, shape, size and other information of the cofferdam.

[0144] Data related to the size of the discharge port: the length (L) of the discharge port, the diameter (used to calculate the average cross-sectional area As), the inlet and outlet cross-sectional areas (A1 and A2), etc.

[0145] Step (3) Establishing a numerical model

[0146] Based on the data collected in step (1), the hydrodynamic model is constructed, the computational grid of the river area is drawn, the terrain is interpolated, and the boundary position is set, such as Figure 4 shown.

[0147] The model time step is 10s, the bottom friction coefficient is set to 0.0016, and the integral calculation is 7 days. The flow field change analysis is carried out by selecting the spring tide moment, that is, the moment with the maximum flow velocity and the highest water level. The upstream is the open boundary of the river, and the hydrodynamic conditions are given in the form of flux. The downstream is the tidal boundary, which is given according to the measured tidal data. In order to calculate the most unfavorable conditions, the most unfavorable flow and spring tide data are selected for calculation.

[0148] Step (4) Set the calculation scheme.

[0149] In the construction area, spillways with different pipe diameters are set, such as: 12 spillways with a diameter of 1.5 m, 11 spillways with a diameter of 2.0 m, and 10 spillways with a diameter of 2.5 m. Here, they are set as concrete spillways, and the parameter is 0.015. In this example, the above three calculation schemes are selected, and the parameters of the above three calculation schemes are introduced into the constructed hydrodynamic model, so as to simulate the engineering scene after adding different calculation spillways to the cofferdam in step (5).

[0150] Step (5) compares the calculation results.

[0151] This step accurately simulates and analyzes the water flow field before and after the cofferdam adds a spillway for the constructed example solution. The specific process is as follows:

[0152] (5.1) Initial water flow field simulation (before engineering)

[0153] Based on the numerical model established in step (3), a hydrodynamic model without spillway was constructed according to the collected river bank, boundary position, topographic data and hydrodynamic data. The computational grid was drawn using triangular mesh in the horizontal direction, the topographic data was interpolated, and the upstream and downstream boundary conditions were set (the upstream is the open boundary of the river, and the hydrodynamic conditions are given in the form of flux; the downstream is the tidal boundary, which is given according to the measured tidal data). The ADI method was used to solve the two-dimensional shallow water equation to simulate the water flow field during the high tide before the project. The low tide rapids during the high tide before the project ( Figure 5 (a)) and high tides ( Figure 5 (b) Flow field distribution near the engineering area, which serves as the basis for subsequent comparison.

[0154] (5.2) Water flow field simulation after the introduction of the spillway (after the project)

[0155] For each set spillway calculation example (such as 11 spillways with a diameter of 2.0 m), the corresponding spillway parameters (pipe diameter, number) are substituted into the hydrodynamic model.

[0156] The hydrodynamic calculation submodel of the spillway is integrated into the model to calculate the head loss under the spillway configuration. The calculated head loss is converted into water level pressure loss and substituted into the water level term of the Navier-Stokes equation as an additional pressure boundary condition or volume force to update the hydrodynamic model.

[0157] The updated model is used for integral calculation (time step is 108, integral calculation is 7 days), and the flow field is re-simulated at the time of high tide (when the flow velocity is the largest and the water level is the highest). Figure 6 (a)) and high tides ( Figure 6 (b) Flow field distribution near the engineering area.

[0158] At the same time, monitor the changes in tide level and flow velocity at points in the project area (such as Figure 7 ), and observe the effect of adding a drain port at different time points.

[0159] The changes in the water flow field caused by the flooding include the rise in water level and the change in flow velocity.

[0160] (5.3) Precise analysis:

[0161] By comparing the flow field and water level change diagrams before and after the project ( Figure 5 and Figure 6), it can be intuitively seen that the maximum flow rate has changed due to the narrowing effect of the cofferdam and the influence of the spillway. For example, it is found that the maximum flow rate has increased by about 0.2m / s, which is 0.2m / s higher than when the spillway is not set, but about 0.2m / s lower than when the spillway setting is not optimized.

[0162] On this basis, the tidal level and flow velocity change diagrams of the project area points under different schemes are analyzed ( Figure 7 ), evaluate the impact of different spillway schemes on water level rise and flow rate increase from a quantitative data perspective. For example, by observing the tidal level and flow rate curves under different schemes, determine the regulating effect of the spillway on the water level and flow rate of the project area during the entire simulation time (7 days), and whether it meets the project requirements (water level rise and flow rate increase not exceeding 20%).

[0163] The flow field here is analyzed by taking 11 spillways with a diameter of 2m as an example. The comparative analysis of the tidal field is similar and will not be expanded here.

[0164] See also Figure 5 , where Figure (a) is the flow field distribution map near the project area during the low tide rapids before the project; Figure (b) is the flow field distribution map near the project area during the high tide rapids before the project.

[0165] See also Figure 6 , where (a) is the flow field distribution map near the project area during the low tide rapids after the project; (b) is the flow field distribution map near the project area during the high tide rapids after the project.

[0166] By comparison, we can see that: similarly, due to the narrowing effect of the earth cofferdam, the maximum flow velocity increases to about 0.7 m / s, which is 0.2 m / s higher than before the project and about 0.2 m / s lower than the increase in the spillway.

[0167] See also Figure 7 , which shows the changes in tide level and flow velocity at points in the project area under different schemes. It can be seen from the figure that the increase in water level and flow velocity in the project area after the earth cofferdam added a spillway did not exceed 20%.

[0168] Step (6) Select a reasonable solution.

[0169] Based on step (5), the results of different solutions are compared and analyzed, and the best solution that meets the engineering requirements is selected.

[0170] In this example, the engineering requirement is that the water level rise and flow rate increase in the engineering area after adding a spillway to the earth cofferdam should not exceed 20%. The ultimate goal of the comparative analysis is to find a spillway design solution that can minimize the engineering cost or perform best in other engineering indicators while meeting the engineering requirements.

[0171] Finally, various factors are comprehensively considered, including the distribution characteristics of the water flow field, the changing trend and amplitude of the water level and flow velocity, and the actual requirements of the project, to evaluate the advantages and disadvantages of different spillway calculation schemes. Finally, it is determined which scheme is most suitable for adding an earth cofferdam trail to the tidal river section under the premise of ensuring the safety of the project (meeting the water level and flow velocity requirements), thereby providing an accurate design basis for the spillway design of the project.

[0172] For example, according to the changes in tide level and flow velocity at the project area under different schemes (such as Figure 7 ), as well as the flow field and water level changes before and after the project (as shown in Figure 5 and Figure 6 As shown in the figure, this is used to evaluate which combination of discharge port diameter and number can better meet the drainage needs of the project while controlling the water level pick-up and flow rate increase.

[0173] At the same time, in this example, in addition to meeting the engineering requirements of water level and flow rate, the engineering cost and other engineering indicators were also considered when the scheme was finally selected.

[0174] Therefore, in this example project, the design scheme of setting 11 2m diameter concrete pipes at the bottom of the earth cofferdam was determined as the optimal solution to meet the engineering requirements.

[0175] It can be seen from the above example scheme that the design scheme of the cofferdam spillway in the tidal river project given by the present invention adopts the improved numerical simulation technology to accurately simulate and analyze the water flow field before and after the cofferdam adds the spillway, which provides a scientific basis for the design of the spillway and can effectively solve the problem of inaccurate spillway design parameters in the prior art.

[0176] Based on the above-mentioned smooth curve construction scheme based on linear and cubic splines, an embodiment of the present invention further provides a computer-readable storage medium on which a program is stored, and when the program is executed by a processor, the steps of the cofferdam spillway design method in the above-mentioned tidal river project are implemented.

[0177] An embodiment of the present invention further provides a processor, which is used to run a program, wherein the program, when running, executes the steps of the above-mentioned method for designing a cofferdam spillway in a tidal river project.

[0178] An embodiment of the present invention also provides a terminal device, which includes a processor, a memory, and a program stored in the memory and executable on the processor, wherein the program code is loaded and executed by the processor to implement the steps of the cofferdam spillway design method in the above-mentioned tidal river project.

[0179] The present invention also provides a computer program product, which, when executed on a data processing device, is suitable for executing the steps of the above-mentioned method for designing a cofferdam spillway in a tidal river project.

[0180] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0181] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and modules described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0182] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0183] The present invention is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products of the embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0184] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0185] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0186] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0187] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0188] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device.

[0189] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0190] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0191] The above-mentioned method of the present invention, or a specific system unit, or a part of the same, is a pure software architecture, which can be arranged on a physical medium, such as a hard disk, an optical disk, or any electronic device (such as a smart phone, a computer-readable storage medium) through program code. When the machine loads the program code and executes it (such as a smart phone loading and executing it), the machine becomes a device for implementing the present invention. The above-mentioned method and device of the present invention can also be transmitted in the form of program code through some transmission media, such as cables, optical fibers, or any transmission mode. When the program code is received, loaded and executed by a machine (such as a smart phone), the machine becomes a device for implementing the present invention.

[0192] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A design method for a cofferdam spillway in a tidal river project, characterized in that: include: Construct a hydrodynamic model for the cofferdam in the target tidal river project; Incorporating a hydrodynamic calculation sub-model of the spillway into the hydrodynamic model to calculate and determine the head loss of the spillway; According to different cofferdam spillway design schemes, based on the improved hydrodynamic model integrated with the hydrodynamic calculation sub-model, an engineering scenario simulation after adding spillway to the cofferdam is formed in the hydrodynamic simulation of the tidal river channel. The flow field and water level changes before and after the project are observed, and the final design scheme is evaluated and determined.

2. The design method of the cofferdam spillway in the tidal river project according to claim 1, characterized in that: In the design method, a hydrodynamic module is constructed based on the Navier-Stokes equations.

3. The design method of the cofferdam spillway in the tidal river project according to claim 2 is characterized in that: The hydrodynamic module constructed in the design method uses a triangular grid in the horizontal direction, and for the case of shallow water in the tidal river, a 2D model with vertical depth and water average is used.

4. The design method of the cofferdam spillway in the tidal river project according to claim 2, characterized in that: The hydrodynamic calculation submodel in the design method can introduce the head loss of the calculated spillway into the hydrodynamic model, and convert the pressure item in the hydrodynamic model when there is no spillway into the water level pressure loss according to the head loss, and correct the deviation of the water level pressure item in the hydrodynamic model accordingly.

5. A design system for a cofferdam spillway in a tidal river project, characterized in that: include: A model building module, wherein the model building module is configured to build a hydrodynamic model for a cofferdam in a target tidal river project; A spillway head loss calculation module, wherein the spillway head loss calculation module is configured to perform data interaction with the model building module, and is capable of integrating a hydrodynamic calculation sub-model of the spillway into the hydrodynamic model to calculate and determine the head loss of the spillway; A scheme confirmation module is configured to interact with the model construction module and the spillway head loss calculation module for data, and can design schemes for different cofferdam spillways, based on an improved hydrodynamic model that incorporates a hydrodynamic calculation sub-model, to form an engineering scenario simulation after the cofferdam is added with a spillway in the hydrodynamic simulation of a tidal river.

6. The design system for the cofferdam spillway in the tidal river project according to claim 5, characterized in that: The model building module builds a hydrodynamic module based on the Navier-Stokes equations.

7. The design system for the cofferdam spillway in the tidal river project according to claim 6, characterized in that: In the above-mentioned power module, a triangular grid is used in the horizontal direction. For tidal channels with shallow water depth, a 2D model with vertical depth and water average is used.

8. The design system for the cofferdam spillway in the tidal river project according to claim 6, characterized in that: The spillway head loss calculation module is configured to introduce the head loss of the spillway determined by the hydrodynamic calculation submodel into the hydrodynamic model, and convert the pressure item in the hydrodynamic model when there is no spillway into the water level pressure loss according to the head loss, and correct the water level pressure item deviation in the hydrodynamic model accordingly.

9. A computer-readable storage medium having a program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method for designing a cofferdam spillway in a tidal river project described in any one of claims 1 to 4 are implemented.

10. A computer program product, characterized in that When executed on a data processing device, it is suitable for executing the steps of the method for designing a cofferdam spillway in a tidal river project as claimed in any one of claims 1 to 4.

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