A transition process research system of long-distance pressure system physical model and numerical simulation coupling

Abstract

The application discloses a kind of long-distance pressure system physical model and the transition process research system of numerical simulation coupling, it is related to long-distance pressure water supply system transition process research technical field.System includes physical model module, numerical simulation module and two-way coupling module;Physical model module is used to simulate the hydraulic characteristics of local building and collects boundary hydraulic parameters, numerical simulation module is used to complete the one-dimensional transition process calculation of upstream and downstream pipeline section, two-way coupling module realizes the real-time two-way data interaction of both, can according to numerical simulation result dynamically regulate and control physical model boundary condition, simultaneously feedback measured parameter of physical model to numerical model.The application effectively solves the problem that single method cannot consider global calculation efficiency and local simulation accuracy in prior art, and the whole physical model test cost is high and long cycle.

Description

Technical Field

[0001] This invention relates to the field of transition process research technology for long-distance pressurized water conveyance systems, and in particular to a transition process research system that couples physical models and numerical simulations for long-distance pressurized systems. Background Technology

[0002] The construction of a modern, high-quality water conservancy infrastructure network, especially long-distance inter-basin water diversion projects, is a major strategic initiative to address the contradiction between water supply and demand in my country. Currently, my country's water diversion projects are developing towards ultra-long distances, ultra-large scales, ultra-large drops in elevation, and multiple branch lines and outlets. The structure of water conveyance systems is becoming increasingly complex, and the hydraulic characteristics of local control structures are having a more significant impact on the overall system's transition process. Reasonable and economical water hammer protection measures are crucial to ensuring the safe and economical operation of these projects, and accurate simulation of the transition process is the core foundation for water hammer protection scheme design.

[0003] Existing research on the transient process of long-distance pressurized water conveyance systems mainly employs three technical approaches: First, pure one-dimensional numerical simulation. This method treats local structures of the water conveyance system as nodes and uses one-dimensional formulas to calculate their hydraulic characteristics. It can efficiently complete transient calculations for the entire line, but it is difficult to accurately describe the complex three-dimensional flow fields in local areas such as valves, tees, bends, and pump station inlets and outlets, resulting in large deviations in the prediction of local water hammer pressure and cavitation characteristics. Second, three-dimensional numerical simulation. This method can accurately capture the details of local flow fields, but the calculation time is huge and cannot be directly applied to the calculation of the transient process of the entire system spanning tens to hundreds of kilometers. Third, physical model testing. This method establishes a scaled-down model according to similarity criteria, which can directly observe parameters such as pressure and flow rate during the transient process, and the results are realistic and reliable. However, for ultra-long water conveyance systems, the construction of an overall scaled-down physical model has obvious drawbacks such as large engineering scale, high investment cost, long test cycle, significant scaling effect, and limited measurement point layout.

[0004] In summary, existing single research methods cannot simultaneously achieve both global computational efficiency and local simulation accuracy. Furthermore, the overall physical model testing is costly and time-consuming, making it difficult to meet the needs of research on the transition processes of modern ultra-long-distance complex pressurized water conveyance systems. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned shortcomings of the prior art and provide a transition process research system that couples physical models and numerical simulations for long-distance pressurized systems. By real-time bidirectional coupling between local physical models and global one-dimensional numerical simulations, the accuracy of local simulations can be significantly improved while ensuring the computational efficiency of the entire system, and the cost and time investment of physical model experiments can be greatly reduced.

[0006] To achieve the above objectives, the present invention provides the following solution: A system for studying the transition process of a long-distance pressurized system coupled with a physical model and numerical simulation includes a physical model module, a numerical simulation module, and a two-way coupling module. The physical model module is used to simulate the hydraulic characteristics of local structures in a long-distance pressurized water conveyance system and to collect hydraulic parameters at the local upstream and downstream boundaries. The numerical simulation module is used to perform one-dimensional transient process numerical calculations on the upstream and downstream pressurized water transmission systems of a long-distance pressurized water transmission system, and output the transient hydraulic parameters of the pipeline segment at each time step. The bidirectional coupling module is communicatively connected to both the physical model module and the numerical simulation module, enabling real-time bidirectional data interaction between them. It dynamically adjusts the boundary input conditions of the physical model module based on the transient hydraulic parameters output by the numerical simulation module, while simultaneously feeding back the local boundary hydraulic parameters collected by the physical model module to the numerical simulation module as the calculation boundary, thus completing the coupled calculation of the entire system's transient process.

[0007] Furthermore, the physical model module includes an upstream water tank, a water supply pipeline, an upstream coupling node, local buildings, a downstream coupling node, a downstream water tank, a return water pipeline, and a water supply pump; the upstream water tank, water supply pipeline, upstream coupling node, local buildings, downstream coupling node, downstream water tank, return water pipeline, and water supply pump are connected in sequence to form a complete circulating water system.

[0008] Furthermore, the numerical simulation module includes an engineering boundary setting unit, a one-dimensional transient process calculation unit, and a data reading and writing unit; The engineering boundary setting unit is used to input the upstream water source reservoir boundary, the water receiving area reservoir boundary, and pipeline foundation parameters of the long-distance pressurized water transmission system. The one-dimensional transient process calculation unit completes the transient hydraulic calculation of the upstream and downstream pressurized water conveyance system based on the boundary hydraulic parameters fed back by the physical model module. The data read / write unit is used to read the boundary hydraulic parameters output by the physical model module and output the calculation results of each time step to the bidirectional coupling module.

[0009] Furthermore, the bidirectional coupling module includes a physical model boundary condition output system, a physical model boundary condition input and automatic control system, and a scale conversion unit; the scale conversion unit is connected to the physical model boundary condition output system and the physical model boundary condition input and automatic control system respectively, and is used to realize the scale conversion of hydraulic parameters between the physical model and the prototype.

[0010] Furthermore, the physical model boundary condition output system includes a pressure sensor, a flow meter, a multi-interface data acquisition instrument, a fiber optic switch, and a user terminal; The pressure sensor and flow meter are respectively installed at the upstream and downstream coupling nodes of the physical model module to collect pressure and flow data at the boundary. The multi-interface data acquisition instrument is electrically connected to the pressure sensor and flow meter, and is used to acquire the analog signals output by the sensors and convert them into digital signals; The fiber optic switch is communicatively connected to the multi-interface data acquisition instrument and is used to transmit the acquired data to the user terminal. The user terminal is used to receive, process, and store boundary hydraulic parameters, and generate data files for the numerical simulation module to read.

[0011] Furthermore, the physical model boundary condition input and automatic control system includes an industrial computer, a servo driver, and an automatic control valve; The industrial control computer is connected to the numerical simulation module and is used to read the transient hydraulic parameters output by the numerical simulation module, compare the measured physical model boundary parameters with the numerical simulation target parameters, and calculate the valve control amplitude. The servo driver is electrically connected to the industrial control computer and is used to receive valve opening commands sent by the industrial control computer and drive the automatic control valve to operate. The automatic control valve is installed on the water supply and return pipes of the physical model module to regulate the flow and pressure at the upstream and downstream boundaries of the physical model.

[0012] Furthermore, the conversion of the scale conversion unit is determined by the geometric scale of the physical model.

[0013] Furthermore, the local structure is a scaled-down model of any one or more of the control gates, tees, bends, and pump station inlets and outlets in a long-distance pressurized water transmission system.

[0014] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects: This invention utilizes real-time bidirectional coupling technology to accurately simulate the hydraulic characteristics of complex local structures using a physical model and correct the boundaries of the numerical model. At the same time, it relies on a one-dimensional numerical model to complete the transient calculation of the entire system. This avoids the problem of excessively long calculation time in three-dimensional numerical simulation and solves the defect of insufficient local accuracy in pure one-dimensional numerical simulation. Only scaled-down physical models of key local structures need to be built, without the need to build an overall model covering the entire line. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 is an overall layout diagram of the coupling transition process between the physical model and numerical simulation of the present invention; Figure 2 is a schematic structural diagram of the physical model module of the present invention; Figure 3 is a detailed schematic structural diagram of the upstream coupling node of the present invention; Figure 4 is a working flowchart of the physical model boundary condition output subsystem of the present invention; Figure 5 is a working flowchart of the physical model boundary condition input and automatic control subsystem of the present invention; Description of marks in the figures: 101 - Upstream water source reservoir, 102 - Water receiving area reservoir, 103 - Upstream pressurized water conveyance system, 104 - Local structure, 105 - Downstream pressurized water conveyance system, 106 - Upstream coupling node, 107 - Downstream coupling node; 201 - Upstream water tank, 202 - Water supply pipeline, 203 - Downstream water tank, 204 - Return water pipeline, 205 - Water supply pump; 301 - Pressure sensor, 302 - Flow meter, 303 - Multi-interface data acquisition instrument, 304 - Optical fiber switch, 305 - User end, 306 - Industrial control computer, 307 - Servo driver, 308 - Automatic control valve. Detailed Description of the Embodiments

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0018] To make the above objectives, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] As Figure 1-5 shown, the system for researching the transition process of coupling a physical model and numerical simulation of a long-distance pressurized system provided in this embodiment relies on the control section of the middle pin-shaped gate of the Yangtze-to-Han River Water Diversion Project to carry out transition process research, and the system includes a physical model module, a numerical simulation module and a two-way coupling module; As Figure 1 shown, wherein 101 is the water level of the upstream water source reservoir, 102 is the water level of the water receiving area reservoir, the upstream pressurized water conveyance system 103 and the downstream pressurized water conveyance system 105 of the middle gate are calculated by a one-dimensional numerical simulation method, and the middle gate 104 is studied by a physical model test.

[0020] As shown in Figure 2, the physical model module comprises an upstream water tank 201, a water supply pipeline 202, an upstream coupling node 106, a pin-shaped gate test section 104, a downstream coupling node 107, a downstream water tank 203, a return water pipeline 204, and a water supply pump 205; wherein the upstream water tank 201, the water supply pipeline 202, the upstream coupling node 106, the pin-shaped gate test section 104, the downstream coupling node 107, the downstream water tank 203, the return water pipeline 204, and the water supply pump 205 are connected in sequence to form a complete circulating water system, which realizes stable water flow circulation and boundary condition regulation.

[0021] The numerical simulation module is configured to perform one-dimensional transient process calculation for the pressured water conveyance system upstream and downstream of the pin-shaped gate of the Yangtze-to-Han River Water Diversion Project. The numerical simulation module includes a project boundary setting unit, a one-dimensional transient process calculation unit, and a data reading and writing unit; the project boundary setting unit inputs basic parameters such as the normal storage water level of the upstream water source reservoir, the normal storage water level of the water receiving area reservoir, and the pipe diameter, wall thickness, and roughness of the upstream and downstream pipelines; the one-dimensional transient process calculation unit adopts the method of characteristics for transient hydraulic calculation; the data reading and writing unit realizes data interaction with the two-way coupling module in a text file format, and the data update frequency is consistent with the time step of numerical calculation.

[0022] The two-way coupling module includes a physical model boundary condition output system, a physical model boundary condition input and automatic control system, and a scale conversion unit.

[0023] As Figure 3 shown, the physical model boundary condition output system includes a pressure sensor 301, a flow meter 302, a multi-interface data acquisition instrument 303, an optical fiber switch 304, and a user terminal 305. The pressure sensor 301 and the electromagnetic flow meter 302 are installed at the upstream coupling node 106 and the downstream coupling node 107, the multi-interface data acquisition instrument 303 collects sensor signals, converts analog signals into digital signals, and transmits the digital signals to the user terminal 305 through the optical fiber switch 304. The user terminal 305 converts the received binary data into decimal data, sorts the data by timestamp, and stores the data as UP_3Ddata.txt and DOWN_3Ddata.txt files respectively for the numerical simulation module to read.

[0024] As Figure 3As shown, the physical model boundary condition input and automatic control system includes an industrial computer 306, a servo driver 307, and an automatic control valve 308. The industrial computer 306 communicates with the computational server of the numerical simulation module via Ethernet to read the boundary target parameters at each time step of the numerical simulation output in real time. The industrial computer 306 compares the measured physical model boundary parameters with the numerical simulation target parameters, calculates the opening adjustment of the automatic control valve 308, and sends pulse commands to the servo driver 307. The servo driver 307 drives the automatic control valve 308 to adjust the flow rate of the water supply pipe 202 and the return water pipe 204.

[0025] The hydraulic parameter conversion using the scale conversion unit is as follows: When physical model data is transferred to a one-dimensional numerical simulation, the flow data needs to be multiplied by... Pressure data multiplied by ( (This refers to the geometric scale of the physical model). When transferring data from a one-dimensional numerical simulation to the physical model, the flow data needs to be divided by... Pressure data divided by .

[0026] The specific working process of the system described in this embodiment is as follows: (1) Initialization of the water conveyance system at time t0. First, the head loss coefficient of the sluice gate 104 is measured; then, based on the upstream boundary 101 and downstream boundary 102 of the entire water conveyance project system, the initial flow rate and pressure distribution along the line of the entire system are calculated to obtain the initial conditions of the entire system at time t0.

[0027] (2) Extract the pressure and head of the upstream coupling node 106 and the downstream coupling node 107, and adjust the boundary conditions of the physical model. At this time, the one-dimensional system and the physical model are successfully initialized.

[0028] (3) Physical model → one-dimensional system data transfer.

[0029] The gate 104 of the test section of the sluice gate begins to close, and the upstream and downstream boundary flow rates of the physical model are collected at time t0+Δt. Q With water head H The system outputs files UP_3Ddata.txt and DOWN_3Ddata.txt respectively. Simultaneously, it uses the method of characteristics to calculate the flow rate and head data at time t0+Δt for both the upstream pressurized water conveyance system 103 and the downstream pressurized water conveyance system 105. The system also reads the three-dimensional boundary data from UP_3Ddata.txt at time t0+Δt. Q _up (t0+Δt) and H _up (t0+Δt)The downstream one-dimensional system reads the three-dimensional boundary data at time t0+Δt from DOWN_3Ddata.txt. Q _down (t0+Δt) and H _down (t0+Δt) At this point, the flow rate and head of the upstream and downstream one-dimensional systems at time t0+Δt have been calculated.

[0030] (4) Data transfer from one-dimensional system to physical model. The boundary control quantities of the physical model at time t0+2Δt of the one-dimensional system are calculated using the method of characteristics. Q _up (t0+2Δt) , H _up (t0+2Δt) , Q _down (t0+2Δt) and H _down (t0+2Δt) And then pass the data to the physical model boundary.

[0031] (5) An automatic control system based on a physical model is adopted to automatically adjust the upstream and downstream boundaries of the model. Q _up (t0+2Δt) , H _up (t0 +2Δt) , Q _down (t0+2Δt) and H _down (t0+2Δt) The hydraulic characteristics of the central sluice gate 104 were observed, and the upstream and downstream boundary flow rates were collected from the physical model at time t0+2Δt. Q With water head H The data is then output to files UP_3Ddata.txt and DOWN_3Ddata.txt respectively; the data is then transferred to the boundary of the one-dimensional numerical simulation. (6) Repeat steps (2), (3), (4) and (5) thereafter to realize the real-time coupling process between the physical model boundary data and one-dimensional calculation, and to realize the real-time coupling transition process analysis between physical model experiment and one-dimensional numerical simulation.

[0032] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0033] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A transition process research system of a long-distance pressure system physical model and numerical simulation coupling, characterized in that, It includes a physical model module, a numerical simulation module, and a two-way coupling module; The physical model module is used to simulate the hydraulic characteristics of local structures in a long-distance pressurized water conveyance system and to collect hydraulic parameters at the local upstream and downstream boundaries. The numerical simulation module is used to perform one-dimensional transient process numerical calculations on the upstream and downstream pressurized water transmission systems of a long-distance pressurized water transmission system, and output the transient hydraulic parameters of the pipeline segment at each time step. The bidirectional coupling module is communicatively connected to both the physical model module and the numerical simulation module, enabling real-time bidirectional data interaction between them. It dynamically adjusts the boundary input conditions of the physical model module based on the transient hydraulic parameters output by the numerical simulation module, while simultaneously feeding back the local boundary hydraulic parameters collected by the physical model module to the numerical simulation module as the calculation boundary, thus completing the coupled calculation of the entire system's transient process.

2. The long-distance pressure system physical model and numerical simulation coupling transition process research system according to claim 1, characterized in that, The physical model module includes an upstream water tank, a water supply pipeline, an upstream coupling node, local buildings, a downstream coupling node, a downstream water tank, a return water pipeline, and a water supply pump; the upstream water tank, water supply pipeline, upstream coupling node, local buildings, downstream coupling node, downstream water tank, return water pipeline, and water supply pump are connected in sequence to form a complete circulating water system.

3. The system for studying the transient process of a long-distance pressurized system coupled with a physical model and numerical simulation, as described in claim 1, is characterized in that... The numerical simulation module includes an engineering boundary setting unit, a one-dimensional transient process calculation unit, and a data reading and writing unit. The engineering boundary setting unit is used to input the upstream water source reservoir boundary, the water receiving area reservoir boundary, and pipeline foundation parameters of the long-distance pressurized water transmission system. The one-dimensional transient process calculation unit completes the transient hydraulic calculation of the upstream and downstream pressurized water conveyance system based on the boundary hydraulic parameters fed back by the physical model module. The data read / write unit is used to read the boundary hydraulic parameters output by the physical model module and output the calculation results of each time step to the bidirectional coupling module.

4. The system for studying the transient process of a long-distance pressurized system coupled with a physical model and numerical simulation, as described in claim 1, is characterized in that... The bidirectional coupling module includes a physical model boundary condition output system, a physical model boundary condition input and automatic control system, and a scale conversion unit. The scale conversion unit is connected to the physical model boundary condition output system and the physical model boundary condition input and automatic control system, respectively, and is used to realize the scale conversion of hydraulic parameters between the physical model and the prototype.

5. The system for studying the transient process of a long-distance pressurized system coupled with a physical model and numerical simulation, as described in claim 4, is characterized in that... The physical model boundary condition output system includes a pressure sensor, a flow meter, a multi-interface data acquisition instrument, a fiber optic switch, and a user terminal. The pressure sensor and flow meter are respectively installed at the upstream and downstream coupling nodes of the physical model module to collect pressure and flow data at the boundary. The multi-interface data acquisition instrument is electrically connected to the pressure sensor and flow meter, and is used to acquire the analog signals output by the sensors and convert them into digital signals; The fiber optic switch is communicatively connected to the multi-interface data acquisition instrument and is used to transmit the acquired data to the user terminal. The user terminal is used to receive, process, and store boundary hydraulic parameters, and generate data files for the numerical simulation module to read.

6. The system for studying the transient process of a long-distance pressurized system coupled with a physical model and numerical simulation, as described in claim 4, is characterized in that... The physical model boundary condition input and automatic control system includes an industrial computer, a servo driver, and an automatic control valve. The industrial control computer is connected to the numerical simulation module and is used to read the transient hydraulic parameters output by the numerical simulation module, compare the measured physical model boundary parameters with the numerical simulation target parameters, and calculate the valve control amplitude. The servo driver is electrically connected to the industrial control computer and is used to receive valve opening commands sent by the industrial control computer and drive the automatic control valve to operate. The automatic control valve is installed on the water supply and return pipes of the physical model module to regulate the flow and pressure at the upstream and downstream boundaries of the physical model.

7. The system for studying the transient process of a long-distance pressurized system coupled with a physical model and numerical simulation, as described in claim 4, is characterized in that... The conversion of the scale conversion unit is determined by the geometric scale of the physical model.

8. The system for studying the transient process of a long-distance pressurized system coupled with a physical model and numerical simulation, as described in claim 2, is characterized in that... The local structures are scaled-down models of any one or more of the control gates, tees, bends, and pump station inlets and outlets in a long-distance pressurized water transmission system.

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