A design method, system and related equipment for a cofferdam spillway in a tidal river project

Abstract

The present invention discloses a design method, system and related equipment for a cofferdam spillway in a tidal river project. This scheme further innovates a head loss calculation method by incorporating the spillway into the hydrodynamic simulation, thereby enabling simulation of an engineering scenario after a cofferdam and spillway are formed in the hydrodynamic simulation of a tidal river, thereby effectively introducing parameters such as water flow characteristics, cofferdam structure, and spillway size, thereby achieving accurate determination of the spillway design scheme, such as the number and size.

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 channel projects, cofferdams serve as temporary water retaining structures, often used for dryland operations during construction. However, in channels significantly affected by tides, the construction of cofferdams often has a significant constricting effect on the surrounding water flow, leading to increased water levels and velocity, posing potential risks to project safety and the surrounding environment. To address this issue, cofferdams with trail-like properties often employ a method of diverting flow by installing spillways of a certain diameter at the bottom of the cofferdam, thereby mitigating the water level rise and increased velocity in the constricted channel.

[0003] Currently, the diameter of the concrete pipes embedded at the bottom of cofferdams in tidal river projects is primarily designed using traditional semi-empirical weir flow formulas. This results in limited accuracy, leading to a more conservative approach to designing cofferdam outfalls. This involves empirically increasing the calculated size to ensure that the actual discharge flow meets the engineering design requirements, but this approach fails to ensure the accuracy of the design parameters.

[0004] Therefore, existing cofferdam spillway design methods lack scientific and systematic principles. They lack in-depth analysis and precise simulation of water flow characteristics when installing spillways in earthen cofferdams. This leads to inaccurate spillway design parameters and an inability to effectively guide construction. This not only affects project cost control but also hides project safety risks. Summary of the Invention

[0005] In response to the problem of inaccurate design parameters in the existing cofferdam spillway design schemes in tidal river projects, the purpose of the present invention is to provide a design scheme for cofferdam spillway in tidal river projects. The scheme 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 method for designing 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 at the spillway;

[0009] For different cofferdam spillway design schemes, based on the improved hydrodynamic model that incorporates the hydrodynamic calculation sub-model, a simulation of the engineering scenario after the cofferdam and spillway are added 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, the design method constructs a hydrodynamic module based on the Navier-Stokes equations.

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

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

[0013] In order to achieve the above-mentioned 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 to design schemes for different cofferdam spillways. Based on the improved hydrodynamic model that incorporates the hydrodynamic calculation sub-model, the scheme confirmation module can simulate the engineering scenario after the cofferdam is added with a spillway in the hydrodynamic simulation of the 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. For shallow tidal channels, 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 calculated by the hydrodynamic calculation sub-model 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 accordingly correct the deviation of the water level pressure item in the hydrodynamic model.

[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 above-mentioned method for designing a cofferdam spillway in a 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 above-mentioned method for designing a cofferdam spillway in a 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 capable of running on the processor. 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 for cofferdam spillways in tidal river projects provided by the present invention innovatively incorporates a head loss calculation model for spillways on the basis of hydrodynamic simulation, thereby realizing the simulation of engineering scenarios after effectively adding cofferdams and spillways in the hydrodynamic simulation of tidal river projects. At the same time, multiple parameters such as water flow characteristics, cofferdam structure, and spillway size are further introduced, so that the design scheme for spillways, such as the number and size, can be scientifically and accurately determined.

[0025] The present invention provides a design scheme for a cofferdam spillway in a tidal river project, which uses 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 river channel project provided by the present invention can significantly improve the scientificity and rationality of the design of the cofferdam spillway in the tidal river channel project when applied in practice, reduce the project cost and safety risks, and has important practical significance and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0028] Figure 1 This is a flowchart for implementing the design of a cofferdam spillway in a tidal river project in an 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 This 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 the hydrodynamic calculation model grid in the 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 the spring tide 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 easier to understand, the present invention is further described below with reference to specific illustrations.

[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 for cofferdam spillways in tidal river projects. Based on hydrodynamic simulation, this 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 river channels, and thus effectively introducing parameters such as water flow characteristics, cofferdam structure, and spillway size on this basis, thereby realizing the accurate determination of the number and size of 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] Based on this foundation, this design solution further incorporates a hydrodynamic calculation sub-model for the outlet into the constructed hydrodynamic model. This hydrodynamic calculation sub-model incorporates cross-sectional area and outlet dimension parameters to calculate and determine the outlet's head loss. Head loss here specifically refers to the mechanical energy loss caused by factors such as fluid viscosity and local flow resistance. This solution uses the hydrodynamic calculation sub-model to calculate the exact value of the head loss, ΔH, and then uses this calculated head loss value to accurately calculate the pressure term η at the outlet in the hydrodynamic model.

[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, thereby determining 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 simulate the engineering scenario 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 present invention first determines and introduces data and parameters related to the cofferdam in the target tidal channel project into the hydrodynamic model. This primarily includes data related to water flow characteristics, cofferdam structure, and outfall dimensions.

[0046] Water flow characteristic data, specifically data used to describe the basic motion and characteristics of water flow, can be used to construct hydrodynamic models. This water flow characteristic data includes: water level (η), water depth (h), vertical average and x- and y-direction flow velocities (u, v), gravitational acceleration (g), dimensionless friction coefficient, Manning's coefficient (n), horizontal eddy viscosity coefficient, and Coriolis coefficient.

[0047] The introduction of cofferdam structure-related data is used to determine the constriction effect of the cofferdam on the water flow and the boundary conditions when constructing the hydrodynamic model. This cofferdam structure-related data specifically includes information such as the cofferdam's location, shape, and size.

[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 of the discharge port (L), 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 the condition of considering various local losses and friction.

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

[0050] Numerical hydrodynamic simulation is preferred, using a triangular grid in the horizontal direction. For shallow tidal channels, a 2D model with vertical depth-water averaging can be used. The mathematical model in the hydrodynamic module is constructed based on the Navier-Stokes equations. By integrating the three-dimensional horizontal momentum equation and continuity equation along the water depth, ignoring the vertical differences in 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 momentum conservation equation and the continuity equation are solved jointly using the ADI method to obtain the hydrodynamic field of each time step. The time step △t is determined by the CFL number.

[0052] As a further illustration, when constructing the mathematical model in the hydrodynamic module based on the Navier-Stokes equations, the present invention specifically integrates the three-dimensional horizontal momentum equation and the continuity equation along the water depth, ignoring the vertical differences 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 flow velocities in the x and y directions (m / s); g is the acceleration due to gravity (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 source and sink 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 is specifically the energy loss caused by friction, local resistance, etc. when water flows through pipes, channels or other flow channels 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 ΔH of the spillway.

[0063]

[0064] Where As is the average cross-sectional area over the length of the outlet, 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 equation, and zb is the elbow loss coefficient.

[0065] Furthermore, the inlet and outlet loss coefficients in the hydrodynamic calculation sub-model can be specifically calculated based on the sum of 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 sub-model 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's coefficient, and R is the average hydraulic radius of the outlet. Manning's n depends on the interior surface of the outlet. Typical values ​​for concrete outlets are 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 this 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 The accurate value of the discharge port can be used to calculate the original state without the discharge port in the numerical solution of the Navier-Stokes equation. 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 resulting hydrodynamic calculation submodel, by comprehensively considering various physical and local structural factors, can more accurately calculate the total head loss at the outlet. For different outlet sizes and river flow characteristics, this submodel can provide more realistic head loss values ​​based on specific parameters, avoiding the large errors that can be introduced by simple empirical formulas. This provides a more accurate data foundation for subsequent calculations, such as substituting head loss into the Navier-Stokes equations.

[0076] Furthermore, the various loss calculations performed by this hydrodynamic calculation sub-model are associated with the actual size of the spillway (such as length, diameter, etc.) and relevant engineering material properties (such as the Manning coefficient), making the calculation results more consistent with actual engineering conditions.

[0077] Furthermore, this hydrodynamic calculation sub-model accurately calculates head loss, allowing for more accurate assessment of the impact of different outfall design options on water flow in subsequent engineering scenario simulations. For example, in tidal river hydrodynamic simulations, accurate head loss calculations can help analyze the water level rise and flow velocity increase under different outfall sizes and numbers, providing a scientific basis for selecting the optimal outfall design. This helps optimize the design of cofferdam outfalls, avoid over- or under-design, and effectively control project costs and reduce engineering risks.

[0078] Furthermore, when integrated with the hydrodynamic module, this hydrodynamic calculation sub-model can effectively enhance simulation realism, enabling more realistic simulations of tidal channel engineering scenarios, reflecting the actual state of water flow in the presence of cofferdams and spillways. By precisely calculating total head loss and accurately solving the hydrodynamic field, the entire hydrodynamic calculation sub-model can present a flow field that is more realistic, providing engineers with more realistic simulation results. This helps to predict and assess the impact of construction on water flow in advance, providing better guidance for the design and implementation of tidal channel engineering projects.

[0079] Furthermore, when integrated with the hydrodynamic module, this hydrodynamic calculation sub-model enables systematic evaluation and comparison of different outfall design options. By accurately calculating head loss and flow conditions under different scenarios, it is possible to quantitatively compare various possible design options (e.g., different pipe diameters and different numbers of outfalls), identifying the optimal solution that meets engineering requirements (e.g., ensuring that water level rise and flow velocity increase do not exceed a certain percentage). This improves the scientific and systematic nature of engineering design and avoids 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 stage, data such as water flow characteristics, cofferdam structure data, and spillway size data are accurately obtained for the target project.

[0083] Flow characteristic data includes information such as water level, depth, vertical average velocity, x- and y-direction velocity, gravitational acceleration, dimensionless friction coefficient, Manning's coefficient, horizontal eddy viscosity coefficient, and Coriolis coefficient for tidal channels. These data serve as the basic input for constructing a hydrodynamic model, reflecting the fundamental flow characteristics of tidal channels.

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

[0085] Outfall Dimensions: Measure and determine the outfall's length, diameter (used to calculate average cross-sectional area), inlet and outlet cross-sectional areas, and other parameters. This data is crucial for accurately calculating the outfall's head loss.

[0086] Hydrodynamic model construction phase:

[0087] (1) Constructing a 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, ignoring the vertical differences in the water body.

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

[0090] The hydrodynamic calculation submodel of the outfall is incorporated into the hydrodynamic model constructed in step (1) to calculate the total head loss of the outfall. The hydrodynamic calculation submodel includes calculations of 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 scenarios.

[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 discharge outlet 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, forming an engineering scenario simulation after the cofferdam adds different discharge outlets.

[0096] (3) Conduct hydrodynamic simulations for each case study and observe the flow field and water level changes before and after the project. This includes comparing the flow field distribution near the project area before and after the project, and recording indicators such as maximum flow velocity and water level rise. At the same time, compare the changes in tidal 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 was analyzed, and the scheme that met the above evaluation criteria was selected as the final cofferdam spillway design scheme.

[0102] Compared with the conventional technology that lacks a better quantitative determination when substituting the head loss generated by the discharge outlet 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 discharge outlet 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 more accurately considering the impact of energy loss on water flow.

[0103] In this way, the design scheme of the cofferdam spillway in the tidal river project provided by the present invention can accurately simulate and analyze the water flow field before and after the cofferdam is added with the spillway by adopting the improved numerical simulation technology, so as to form accurate design parameters for the cofferdam to add the spillway, and provide 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 features:

[0105] (1) Comprehensive consideration of various head loss factors: When constructing the hydrodynamic module and hydrodynamic calculation sub-model in the present invention, not only common friction loss parameters are introduced, but also other possible loss conditions such as local losses at the inlet and outlet and elbow losses are fully considered. By comprehensively calculating 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 conditions at the discharge port in actual engineering scenarios. Compared with the existing conventional technology that simply considers part of the head loss or uses empirical estimation, the final result determined by the present invention is more systematic and accurate.

[0106] (2) Calculations based on actual engineering parameters: The hydrodynamic module in the present invention is closely related to actual engineering parameters, such as the actual dimensions of the outfall (length, diameter, inlet and outlet cross-sectional areas, etc.) and related engineering material properties (such as the Manning coefficient). This allows the hydrodynamic 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 meshing: The hydrodynamic module in the present invention specifically uses a hydrodynamic numerical simulation approach, employing a triangular mesh in the horizontal direction. For shallow tidal channels, a 2D model with vertical depth-water averaging is used. This meshing approach, combined with numerical simulation, is more suitable for the characteristics of tidal channel flow. Compared with conventional simple averaging or rough meshing, it can more accurately simulate the flow state of tidal channels.

[0108] (4) Combining multiple equations and calculation methods: The hydrodynamic module in the present invention integrates the three-dimensional horizontal momentum equation and the continuity equation along the water depth, ignoring the vertical differences in the water body, to obtain a two-dimensional shallow water equation. The Manning coefficient is used to calculate bottom friction. 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, where the time step is determined by the CFL number. This organic combination of multiple schemes can achieve more accurate hydrodynamic field simulation compared to conventional single calculations or rough equation solutions.

[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 more accurately simulate the hydrodynamic field of tidal channels, especially considering the water flow state in the presence of cofferdams and spillways. By more accurately calculating head losses and taking them into account, the simulation results are closer to actual engineering scenarios, which helps to improve the scientificity and rationality of cofferdam and spillway designs.

[0111] (2) Due to the comprehensive consideration of multiple factors, 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, thereby better controlling engineering costs and reducing 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 for cofferdam outlets in tidal channel projects provided by the present invention can, in specific applications, be implemented as a corresponding software program, forming a corresponding system for designing cofferdam outlets in tidal channel projects. When executed, the software program executes the design method for cofferdam outlets in tidal channel projects and stores the data in a corresponding storage medium for access and execution by a processor.

[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 is capable of integrating 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 based on the schemes shown in the aforementioned 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 outlet, 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 equation, and zb is the elbow loss coefficient.

[0123] Furthermore, the inlet and outlet loss coefficients in the hydrodynamic calculation sub-model can be specifically calculated based on the sum of 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 sub-model 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's coefficient, and R is the average hydraulic radius of the outlet. Manning's n depends on the interior surface of the outlet. Typical values ​​for concrete outlets are 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 discharge port head loss calculation module can integrate the constructed hydrodynamic calculation sub-model with the hydrodynamic module, and be configured to be able to introduce the calculated head loss accurate value △H to determine the pressure term of the discharge port 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, specifically, the discharge port can be used to calculate the original state without a discharge port in the numerical solution of the Navier-Stokes equation. 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 described below through specific application examples.

[0134] This example takes the construction of an earthen cofferdam and footpath in a tidal river section as an example. First, a design system for the cofferdam and spillway in the corresponding tidal river section is constructed. The specific construction scheme is as described above and will not be elaborated 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. To this end, 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 In this example, the main structural design of the temporary road and platform in the earth cofferdam trail project in the tidal river section is as follows: the top surface elevation of the temporary road and platform is 3m; the temporary 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 temporary 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, the diameter and number of concrete spillways at the bottom need to be determined.

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

[0142] Data related to water flow characteristics: including water level (η), water depth (h), vertical average and x- and y-direction flow velocities (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), diameter (used to calculate the average cross-sectional area As), 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 was 10 seconds, the bottom friction coefficient was set to 0.0016, and the integral calculation lasted for 7 days. The flow field variation analysis was performed at spring tide, when the flow velocity and water level are at their highest. The upstream boundary was the open river boundary, and the hydrodynamic conditions were given in the form of flux. The downstream boundary was the tidal boundary, which was given based on measured tidal data. To calculate the most unfavorable conditions, the most unfavorable flow and spring tide data were used for the calculation.

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

[0149] In the construction area, discharge ports of different diameters are set, such as: 12 discharge ports with a diameter of 1.5 m, 11 discharge ports with a diameter of 2.0 m, and 10 discharge ports with a diameter of 2.5 m. Here, they are set as concrete discharge ports, 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 scenario after adding different calculation example discharge ports to the cofferdam in step (5).

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

[0151] This step accurately simulates and analyzes the flow field before and after adding a spillway to the cofferdam based on the constructed calculation example. The specific process is as follows:

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

[0153] Based on the numerical model established in step (3), a hydrodynamic model without the discharge port was constructed according to the collected river bank, boundary position, topographic data and hydrodynamic data. By using triangular mesh to draw the calculation grid in the horizontal direction, interpolating the topographic data, setting the upstream and downstream boundary conditions (the upstream is the river open boundary, the hydrodynamic conditions are given in the form of flux, and the downstream is the tidal boundary, which is given according to the measured tidal data), the ADI method is 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 tide rapids ( 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 outfall calculation scheme (e.g., 11 outfalls with a diameter of 2.0 m), the corresponding outfall parameters (diameter, number) are substituted into the hydrodynamic model.

[0156] A hydrodynamic submodel for the outfall is incorporated into the model to calculate the head loss for this outfall configuration. The calculated head loss is converted into a 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 spring tide (when the flow velocity is the largest and the water level is the highest). The time of the ebb rapids during the spring tide after the project is obtained ( Figure 6 (a)) and high tide ( Figure 6 (b) Flow field distribution near the engineering area.

[0158] At the same time, monitor the changes in tide level and flow rate at points in the project area (such as Figure 7 The addition of the drain port at different time points was observed.

[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 constriction effect of the cofferdam and the influence of the spillway. For example, the maximum flow rate was found to increase by about 0.2 m / s compared to when no spillway was installed, but it was about 0.2 m / s lower than when the spillway was not optimized.

[0162] On this basis, the tide level and flow velocity change diagrams of the project area points under different schemes are analyzed ( Figure 7 ) and quantitatively evaluate the impact of different spillway options on water level rise and flow velocity. For example, by observing the tidal and flow velocity curves under different options, we can determine the spillway's regulatory effect on the water level and flow velocity in the project area over the entire simulation time (7 days) and whether it meets the project requirements (water level rise and flow velocity increase not exceeding 20%).

[0163] The flow field here is analyzed by taking 11 2m diameter outfalls 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 ebb tide and rapids before the project; Figure (b) is the flow field distribution map near the project area during the flood tide and rapids before the project.

[0165] See also Figure 6 , where Figure (a) is the flow field distribution map near the project area during the ebb tide and rapids after the project; Figure (b) is the flow field distribution map near the project area during the flood tide and 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 when the spillway was increased.

[0167] See further 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 after the earth cofferdam adds a spillway, the water level rise and flow velocity increase in the project area do not exceed 20%.

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

[0169] Based on the comparative analysis of the results of different solutions in step (5), the optimal solution that meets the engineering requirements is selected.

[0170] In this example, the project requirement is that the addition of a spillway to the earthen cofferdam should not increase the water level or flow velocity in the project area by more than 20%. The ultimate goal of this comparative analysis is to identify a spillway design that minimizes project costs or optimizes other project performance indicators while still meeting the project requirements.

[0171] Finally, the advantages and disadvantages of different spillway calculation schemes were evaluated by comprehensively considering various factors, including the distribution characteristics of the water flow field, the changing trends and magnitudes of water levels and flow velocities, and the actual project requirements. Ultimately, the optimal solution for adding an earthen cofferdam and trail to this tidal river section, while ensuring project safety (meeting water level and flow velocity requirements), was determined. This provided a precise basis for the spillway design of the project.

[0172] For example, according to the changes in tide level and flow rate 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, we can 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 case, 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 project requirements.

[0175] The above-mentioned example scheme shows that the design scheme of the cofferdam spillway in the tidal river project provided by the present invention adopts the improved numerical simulation technology to accurately simulate and analyze the water flow field before and after the spillway is added to the cofferdam, providing a scientific basis for the design of the spillway, and effectively solving 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 having a program stored thereon, which, when executed by a processor, implements the steps of the above-mentioned method for designing a cofferdam spillway in a tidal river project.

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

[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 runnable on the processor. The program code is loaded and executed by the processor to implement the steps of the above-mentioned method for designing a cofferdam spillway in a 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 focus. 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 will 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] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, 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 magnetic 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 flowcharts and / or block diagrams, as well as the combination of processes and / or blocks in the flowcharts and / or block diagrams, 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 produce 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 flowcharts and / or block diagrams. 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 that can direct a computer or other programmable data processing device to work 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 The 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 operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps for the function specified in one or more boxes.

[0186] In a typical configuration, a computing device includes one or more processors (CPUs), 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. The 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 disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices or any other non-transmission medium that can be used to store information that can be accessed by a computing device.

[0189] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0190] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, 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 magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0191] The aforementioned methods, or specific system units, or portions thereof, of the present invention are purely software-based and can be implemented as program code on physical media, such as a hard drive, optical disk, or any electronic device (e.g., a smartphone or computer-readable storage medium). When a machine loads and executes the program code (e.g., a smartphone), the machine becomes a device for implementing the present invention. The aforementioned methods and devices of the present invention can also be transmitted in program code form via some transmission medium, such as a cable, optical fiber, or any other transmission method. When the program code is received, loaded, and executed by a machine (e.g., a smartphone), the machine becomes a device for implementing the present invention.

[0192] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A design method for a cofferdam spillway in a tidal river project, characterized in that: include: A hydrodynamic model was constructed for the cofferdam in the target tidal channel project. The constructed hydrodynamic module used a triangular grid in the horizontal direction. For shallow tidal channels, a 2D model with vertical depth-water averaging was used. Incorporating a hydrodynamic calculation sub-model of the spillway into the hydrodynamic model to calculate and determine the head loss at the spillway; The hydrodynamic calculation sub-model can introduce the calculated head loss of the discharge port into the hydrodynamic model, and convert the pressure term in the hydrodynamic model when there is no discharge port into the water level pressure loss according to the head loss, and accordingly correct the deviation of the water level pressure term in the hydrodynamic model; For different cofferdam spillway design schemes, based on the improved hydrodynamic model that incorporates the hydrodynamic calculation sub-model, a simulation of the engineering scenario after the cofferdam and spillway are added 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 method for designing a cofferdam spillway in a 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. A design system for a cofferdam spillway in a tidal river project, characterized in that: include: a model building module configured to construct a hydrodynamic model for a cofferdam in a target tidal channel project; wherein the hydrodynamic model utilizes a triangular grid in the horizontal direction and, for shallow tidal channels, utilizes a 2D model with vertical depth-water averaging; 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; The drain port head loss calculation module is configured to introduce the drain port head loss calculated by the hydrodynamic calculation sub-model into the hydrodynamic model, convert the pressure term in the hydrodynamic model when there is no drain port into the water level pressure loss according to the head loss, and correct the water level pressure term deviation in the hydrodynamic model accordingly; A scheme confirmation module is configured to interact with the model construction module and the spillway head loss calculation module to design schemes for different cofferdam spillways. Based on the improved hydrodynamic model that incorporates the hydrodynamic calculation sub-model, the scheme confirmation module can simulate the engineering scenario after the cofferdam is added with a spillway in the hydrodynamic simulation of the tidal river.

4. The design system for the cofferdam spillway in the tidal river project according to claim 3, characterized in that: The model building module builds a hydrodynamic module based on the Navier-Stokes equations.

5. 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 according to any one of claims 1 to 2 are implemented.

6. 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 2.

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