Fluid-structure interaction rapid calculation method for complex fluid control system

Abstract

The invention discloses a fluid-structure interaction rapid calculation method for a complex fluid control system, and relates to the technical field of fluid-structure interaction, and the method comprises the steps: dividing the complex fluid control system into a control flow path and a supply flow path; establishing a zero-dimensional mathematical model based on the control flow path and determining corresponding solution program information; establishing a three-dimensional grid model based on the supply flow path and determining corresponding CFD numerical simulation program information; determining a user-defined function program which is used for realizing bidirectional fluid-solid coupling of the zero-dimensional mathematical model and the three-dimensional grid model based on solution program information and CFD numerical simulation program information; and compiling solution program information of the zero-dimensional mathematical model into a dynamic link library and a static link library, loading a user-defined function program in an external compiling manner to call the dynamic link library and the static link library, and completing fluid-solid coupling calculation within a preset duration. According to the method, an accurate fluid-solid coupling calculation result can be quickly obtained.

Description

Technical Field

[0001] The present application relates to the field of fluid-solid coupling technology, and in particular to a fast fluid-solid coupling calculation method for complex fluid control systems. Background Art

[0002] In the field of pipeline and valve design, a fluid control system is typically simplified by constructing a mathematical model, and the system's performance and control characteristics are determined by solving the mathematical model equations. This numerical simulation method significantly simplifies the flow of the entire control system, abstracting the three-dimensional flow into a zero-dimensional flow with only average parameters such as average pressure and average velocity. This is simplified by introducing empirical formulas. While numerical simulation methods can guarantee high accuracy when sufficient experimental data is available, when studying dynamic characteristics, due to the aforementioned reasons, they often overlook the influence of the flow itself on the system, resulting in a significant decrease in the accuracy of the results and even significant deviations.

[0003] As computer computing power increases, computational fluid dynamics (CFD) technology is becoming increasingly mature. Compared to zero-dimensional modeling methods that abstractly simplify fluid flow, CFD subdivides the flow area into a certain number of small areas, called grids, and solves the fluid control equations such as the NS equations for the fluid within each grid, thereby obtaining an analytical solution for the fluid within that grid area in the flow field. This method can obtain more details about the flow, making the calculation of the entire flow field more accurate, and can help understand and predict the behavior of fluids in complex environments.

[0004] While CFD can significantly improve computational accuracy, it also consumes vastly more computing resources. This is especially true for models with complex geometric structures, such as valves and pipelines, where different regions within the valve have significantly different geometric scales (e.g., a fuel metering system comprised of several precision valves and pipelines). To achieve convergence in the calculations, the mesh in areas with complex flow and smaller geometric scales often needs to be densified. This significantly increases the number of meshes, directly increasing the computational resources required and slowing down the calculations. Summary of the Invention

[0005] The purpose of this application is to provide a fast calculation method for fluid-structure coupling for complex fluid control systems, which can quickly obtain accurate fluid-structure coupling calculation results.

[0006] To achieve the above objectives, this application provides the following solutions:

[0007] This application provides a fast calculation method for fluid-structure coupling for complex fluid control systems, including:

[0008] Divide the complex fluid control system into control flow path and supply flow path;

[0009] Establishing a zero-dimensional mathematical model based on the control flow path, and determining corresponding solution program information according to the zero-dimensional mathematical model;

[0010] Establishing a three-dimensional grid model based on the supply flow path, and determining corresponding CFD numerical simulation program information according to the three-dimensional grid model;

[0011] Determining a user-defined function program; wherein the user-defined function program is used to: realize bidirectional fluid-solid coupling between the zero-dimensional mathematical model and the three-dimensional grid model based on the solver information and the CFD numerical simulation program information;

[0012] The solver information of the zero-dimensional mathematical model is compiled into a dynamic link library and a static link library, and then the user-defined function program is loaded through external compilation to call the dynamic link library and the static link library to complete the fluid-solid coupling calculation within a preset time.

[0013] According to the specific embodiments provided in this application, this application has the following technical effects: This application divides the complex fluid control system into a control flow path and a supply flow path according to the structural characteristics of the complex fluid control system, constructs a zero-dimensional mathematical model for the control flow path, and constructs a three-dimensional grid model for the supply flow path, and then couples the above two models through a user-defined function program, avoiding the shortcomings of the two methods while retaining the respective advantages of the two methods, reducing the difficulty of simulation calculations, saving calculation time and calculation resources, and greatly improving the calculation accuracy. While obtaining system characteristics, it can also obtain flow details that are difficult to obtain in experiments, provide guidance for structural optimization, and thus achieve rapid fluid-solid coupling calculations for complex fluid control systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0015] Figure 1 This is a simplified schematic diagram of a fluid-structure coupling calculation method according to an embodiment of the present application.

[0016] Figure 2 Schematic diagram of a flow chart of a fast calculation method for fluid-structure coupling in a complex fluid control system according to an embodiment of the present application.

[0017] Figure 3 A schematic diagram of the structure of a computer device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0019] This application introduces computational fluid dynamics (CFD) methods while combining the advantages of traditional methods to avoid the shortcomings of CFD. In complex fluid control systems, CFD methods are used for areas where the flow has a greater impact on the system, while zero-position mathematical modeling is used for areas where the flow is more stable and has a smaller impact on the system. The results of these two methods are coupled in real time at each time step, achieving coupled calculations of fluid and solid motion, significantly reducing the required computing resources while ensuring accuracy.

[0020] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0021] In an exemplary embodiment, Figure 1 As shown, a fast calculation method for fluid-solid coupling of complex fluid control systems is provided, which is executed by a computer device, specifically, it can be executed by a computer device such as a terminal or a server alone, or it can be executed by a terminal and a server together. Specifically, this application divides the various components in the complex fluid control system into supply flow paths and control flow paths according to their actual functions; establishes a zero-dimensional mathematical model for the control flow path, writes a solution program, and packages it into a link library file for subsequent calls; establishes a three-dimensional grid model for the supply flow path, and uses Fluent software for fluid calculation; writes a UDF program to control the boundary condition changes of the fluid calculation and call the zero-dimensional mathematical model solution program of the control flow path. The flow field parameters (such as pressure) at several positions in the supply flow path are the boundary conditions for the control flow path solution. The pressure of the control flow path solution controls the movement of the valve in the supply flow path, and is bidirectionally coupled at each time step, thereby realizing fast bidirectional fluid-solid coupling calculation.

[0022] In another exemplary embodiment, Figure 2 As shown, in the embodiment of the present application, the following steps 101 to 105 are included.

[0023] Step 101 : Divide the complex fluid control system into a control flow path and a supply flow path.

[0024] A complex fluid control system can be divided into two parts based on the roles of various valves, pipelines, and other components within the system: the supply flow path, where parameters such as flow rate and pressure serve as the primary control and output targets; and the control flow path, responsible for automatically controlling and regulating the movement of various components. Compared to the control flow path, the fluid in the supply flow path has a higher flow rate and faster flow velocity. The unsteady phenomena generated by this flow have a greater impact on the control stability of the complex fluid control system. Therefore, three-dimensional fluid flow calculations are used for this part of the flow path.

[0025] In a specific application, when dividing the control flow path into supply flow paths, all piping connected to the control flow path components is placed in the control flow path to minimize the computational resources used for flow calculations in the supply flow path. The supply flow path retains the valve's main flow path responsible for supply, and control-related spring chamber flow paths are also placed in the control flow path.

[0026] In a practical application, the complex fluid control system may be a fuel metering system. A fuel metering system is a control system composed of a number of precision valves and pipelines. In practical engineering applications, the fuel flow area of ​​a fuel metering system can be roughly divided into two parts. One part of the oil is mainly used to control the movement of the valve cores of each valve in the system. This oil circuit is called the control oil circuit. The fuel flow in the control oil circuit is relatively low, and the main driving force is the fuel pressure difference between different areas to control the movement of the valve core. The fuel in the other part flows out of the system at a set flow rate under control. This oil circuit is called the oil supply oil circuit. The fuel flow in this oil circuit is relatively large, and the steady-state fluid force and transient fluid force have a greater impact on the system.

[0027] Step 102: Establish a zero-dimensional mathematical model based on the control flow path and determine the corresponding solver information based on the zero-dimensional mathematical model. The solver information includes a dynamic link library (DLL) and a static link library (SL). The dynamic link library is compiled from the solver program, while the static link library is compiled from a header file. Three external functions are declared in the header file: the first is used to initialize flow field boundary conditions, the second is used to initiate an iterative solution at each time step, obtain a solution result, and output it. The third is used to save the solution result and use it as flow field initialization data for the next time step.

[0028] When using dynamic link libraries and static link libraries, some software will provide interfaces for users to perform secondary development during calculations. The user-defined interface of AMESim software is a dynamic link library. By using this application, coupled calculations between Fluent software and Amesim software can also be achieved.

[0029] The zero-dimensional mathematical model includes the flow equation and the mechanical equation. On this basis, the solution process includes the following steps:

[0030] (21) Based on the flow equation and the mechanical equation, the dynamic balance differential equation and dynamic model of each component are established, thereby obtaining the dynamic balance differential equation and dynamic model of each component at the valve and in the pipeline.

[0031] (22) According to the dynamic equilibrium differential equations and dynamic models of each component, determine the dynamic partial differential equation group.

[0032] (23) The dynamic partial differential equations are discretized to obtain difference equations; specifically, the continuous partial differential equations are discretized in time and converted into time difference equations.

[0033] (24) Solving the differential equation according to the flow field boundary conditions to obtain a solution result; the solution result includes the moving pressure of each component in the next time step and the position of the current time step, that is, the pressure of the valve movement in the control supply flow path and the position of the valve in the flow path in each time step.

[0034] In a specific application, step 102 can be compiled using the Developer Command Prompt for VS compiler of Visual Studio in a Windows system, or using a compiler installed with a g / g++ runtime environment in a Linux system.

[0035] Since the fluid in the control flow path mainly provides pressure for valve motion control, the flow rate is relatively small, and the flow itself has little impact on complex fluid control systems. In order to achieve the ideal control effect, the control flow path contains a large number of valves and pipelines. Using CFD calculation methods will add a lot of "meaningless" grids and reduce the efficiency of simulation calculations. Therefore, this application solves the control flow path through mathematical modeling, which can greatly save computing costs while ensuring the accuracy of the system's numerical calculations.

[0036] Step 103: Establish a three-dimensional mesh model based on the supply flow path, and determine corresponding CFD numerical simulation program information based on the three-dimensional mesh model. In a fluid control system, the flow rate of the fluid in the supply flow path is the control target of the entire complex fluid control system. A large flow rate of fluid in the supply flow path has a significant impact on the movement of the valve, and the flow rate itself is also an important indicator of the control characteristics of the complex fluid control system. Therefore, a three-dimensional mesh model is created for the supply flow path, and then numerical simulation calculations are performed using CFD methods to capture the specific flow details at key locations (such as the valve core outlet) to meet the required accuracy.

[0037] Wherein, establishing a three-dimensional grid model based on the supply flow path includes:

[0038] (31) The supply flow path is divided into a valve core movement area and a stationary area; specifically, a three-dimensional model of the fluid domain of the supply flow path is established according to the specific structure of the complex fluid control system, and the valve core movement area is modeled separately from other stationary areas.

[0039] (32) The static area is established as an unstructured grid according to a first preset setting condition; wherein the first preset setting condition includes: locally encrypting the area where the pressure gradient is within the preset gradient range, such as locally encrypting the area with a larger pressure gradient such as the valve-type hole; setting the surface where the static area intersects with the valve core movement area as a static interface, and the difference between the grid size of the static interface and the grid size of the valve core movement area is within the preset size range.

[0040] (33) According to the second preset setting condition, the valve core movement area is established as a structured grid, and the valve core movement surface is perpendicular to the movement direction; the unstructured grid and the structured grid constitute a three-dimensional grid model; wherein, the second preset setting condition includes: the surface where the valve core movement area intersects with the static area is set as the movement interface, and the difference between the grid size of the movement interface and the grid size of the static area is within a preset size range; the grid height of the valve core movement area is matched with the moving speed, so that the displacement of the valve core movement surface within one time step is not higher than one grid height.

[0041] After the three-dimensional grid model is constructed through the above steps, the CFD numerical simulation program information includes the following steps: importing the unstructured grid and the structured grid into Fluent software, setting the turbulence model, heat transfer model and multiphase flow model, setting grid boundary conditions and physical parameters, and matching the grids of the static interface and the moving interface one-to-one; obtaining the flow field initialization data of the current time step as the data basis for updating the grid of the three-dimensional grid model.

[0042] Among them, transient calculation requires reasonable initialization of the flow field data. Before starting the calculation, it is adjusted to steady-state calculation, and the calculated flow field data is used as the initialization flow field data for transient calculation; after that, it is adjusted to transient calculation, and the calculation results at the current time step will be used as the flow field data at the beginning of the next time step calculation.

[0043] In addition, the time step in the control flow path is consistent with the time step of the fluid calculation in the supply flow path.

[0044] Step 104: Determine a user-defined function (UDF); the user-defined function is used to implement bidirectional fluid-structure coupling between the zero-dimensional mathematical model and the three-dimensional mesh model based on the solver information and the CFD numerical simulation program information. Specifically, this application writes a user-defined function to achieve the coupling of zero-dimensional and three-dimensional data and control the motion of the three-dimensional mesh model. The static and dynamic link library for solving the flow control is compiled and called in the Fluent software.

[0045] This application is a secondary development based on the fluid calculation software Fluent. In computational fluid dynamics, UDF is a method of extending the functionality of a CFD solver through programming. UDF allows users to customize boundary conditions, physical parameters, source terms, or control methods based on standard CFD solver functions (such as ANSYS Fluent) to meet complex or special engineering requirements. In a specific application, the data processing process of the user-defined function program at each time step includes the following steps:

[0046] (41) Collecting the flow field boundary conditions that affect the zero-dimensional calculation in the current time step flow field. When the complex fluid control system is a fuel metering system, the flow field boundary conditions that affect the zero-dimensional calculation are the pressure affecting the control oil circuit and the real-time valve core opening obtained by the three-dimensional grid model (i.e., the oil supply circuit) through CFD calculation.

[0047] (42) Based on the flow field boundary conditions and the solver information, an iterative solution is performed to obtain a solution result; the solution result includes the displacement pressure of each component at the next time step and the position of the component at the current time step. When the complex fluid control system is a fuel metering system, the solution result includes the displacement pressure for controlling the movement of each valve core at the next time step and the position of the valve core at the current time step.

[0048] (43) Establish the force balance differential equation of valve core movement.

[0049] (44) Based on the force balance differential equation, according to the solution result and the flow field boundary conditions, the movement speed of the valve core in the next time step is calculated.

[0050] (45) Feeding the movement speed back into the three-dimensional mesh model to perform mesh updating, obtaining updated flow field boundary conditions, and then entering the next time step iteration based on the updated flow field boundary conditions. Specifically, based on the movement speed of the valve core in the next time step, the macro parameters of the mesh movement are controlled using Fluent software, the velocity of the valve core movement surface is updated, and the mesh movement update is completed.

[0051] Step 105 compiles the zero-dimensional mathematical model solver information into a dynamic link library and a static link library, then loads the user-defined function program via external compilation to call the dynamic link library and the static link library to complete the fluid-structure interaction calculation within a preset duration. The user-defined function program is compiled into a dynamic link library via external compilation and loaded into the Fluent software, and then the dynamic link library and the static link library are called in the Fluent software to complete the fluid-structure interaction calculation within the preset duration.

[0052] Because the call to the external function (contained in the dynamic and static link library) is used in the UDF program, the exchange between data can be completed, and then the control flow path to the supply flow path can be realized. However, since the compilation environment of Fluent software is pure C language, it is impossible to use the Windows API function that comes with Windows that C++ can use, and it is impossible to directly call the static link library and dynamic link library. If C language wants to call other programs, it can only use external functions. By linking static libraries or dynamic libraries, the external functions declared in the library are used to achieve the purpose of calling by calling these functions. However, such programs cannot be directly compiled in Fluent software. Because only the UDF control program can be input when Fluent software is compiled, the compiler cannot find the external function, resulting in the compilation failure of the parameters during compilation. However, when Fluent software is compiled, the method adopted is also to compile the UDF program into a dynamic link library and call it, which makes it possible for Fluent to call an external link library by external compilation. The operating method is roughly the same under Windows system and Linux. Taking Linux system as an example, this application uses Fluent2023R1 version.

[0053] Based on the above content, step 105 specifically includes the following steps:

[0054] (51) Use Fluent software to compile an initial UDF program (do not click to load at this time) to obtain a libudf folder; the libudf folder includes a src folder and a lnamd64 folder; the lnamd64 folder includes a 3ddp_host folder and a 3ddp_node folder.

[0055] The src folder is used to store UDF programs. Fluent software uses parallel computing technology in its actual calculations. This technology distributes a computing task among several nodes, called nodes, and is coordinated by a master node, called the host. The lnamd64 folder contains two folders, 3ddp_host and 3ddp_node, which store compiled UDF executable files for the host and node, respectively. The src, 3ddp_host, and 3ddp_node folders all contain makefiles, which record the compilation rules used by Fluent software.

[0056] (52) Save the user-defined function program to the src folder.

[0057] (53) Save the .so file to the same root directory of the libudf folder, and save the .a file to the 3ddp_hope folder and the 3ddp_node folder respectively; wherein, the .so file refers to the dynamic link library, and the .a file refers to the static link library. In short, the dynamic link library is a .so file under the Linux system, and the static link library is a .a file.

[0058] The above-mentioned user-defined function programs, .a files, and .so files are saved in the same manner. Taking the user-defined function program as an example, saving the user-defined function program to the src folder includes: renaming the user-defined function program to the name of the program in the src folder and overwriting the program in the src folder so that the Fluent software can still recognize it normally. Furthermore, specifically: assign a value after the empty function "USER_OBJECTS=", fill in the file name of the user-defined function program, and save it.

[0059] (54) Reset the compilation environment through the make clean command. Specifically, with the help of the system's built-in command line terminal, open the 3ddp_hope folder and enter the command make clean to clear the compiled file generated in step (51). Then use the make command to recompile all files in the same root directory of the modified libudf folder. Specifically, recompile according to the compilation rules in the makefile file modified in the above steps (52) and (53). In this way, through external compilation, the problem that Fluent software cannot compile C++ programs and cannot compile programs containing external functions is bypassed. Mount the recompiled files to Fluent software, and the coupling of zero-dimensional and three-dimensional data is realized. Finally, click load to complete the call of the user-defined function program and start the fluid-solid coupling calculation of the preset time.

[0060] At this point, this application "cheats" the software and uses external compilation to bypass the problem that the software cannot directly compile programs containing external functions, so that the Fluent software can couple zero-dimensional calculation data when calculating three-dimensional flow. Through UDF control, the flow field information is coupled with the zero-dimensional calculation data at each time step, thereby controlling the grid movement of the flow field and realizing fast and accurate fluid-solid coupling calculation.

[0061] In a specific application, a three-dimensional model of the supply flow path is established to distinguish between moving areas and static areas, a grid is drawn and CFD calculations are performed; a mathematical model is established for the control flow path; user-defined function programs are written, etc. The Fluent2023R1 software can be used. The Windows system used needs to install the c / c++ language compilation environment. This application can be completed using Visual Studio 2022, and the Linux system used can be equipped with the g / g++ operating environment.

[0062] After completing the above software settings and before clicking Load, you still need to make the following settings: Change the calculation case in the 3D mesh model to a transient calculation, select the Layering option in the 3D mesh model's Dynamic Mesh settings, select the name of the function used for mesh control in the User-Defined Function program in the Motion Law field, and enter the height of the structured mesh in the moving area of ​​the 3D mesh model in the Mesh Height field. In the Calculation Settings, enter the time step of the solver information in the Time Step field, and enter the desired number of iterations (iteration time) in the Iteration Time field. The number of iterations is equal to the required calculation time divided by the time step.

[0063] In summary, this application provides a way to simplify the CFD simulation calculation of fluid flow. For complex fluid control systems where the flow details of the fluid in a part of the flow path have little effect on the system characteristics, but it is also an important control component of the entire system, this application couples the two methods, avoiding the shortcomings of the two methods while retaining the advantages of each method, so as to achieve fast fluid-solid coupling calculation for complex fluid control systems. In other words, this application can be used to greatly reduce the difficulty of system simulation calculations, greatly saving calculation time and computing resources. Compared with traditional calculation methods, it greatly improves the calculation accuracy while speeding up the calculation speed. While obtaining the characteristics of complex fluid control systems, it can also obtain flow details that are difficult to obtain experimentally, providing guidance for structural optimization.

[0064] Based on the same inventive concept, the embodiments of the present application also provide a system for implementing the above-mentioned methods. The implementation solution provided by the system is similar to the implementation solution described in the above-mentioned method. Therefore, the specific limitations of one or more system embodiments provided below can be referred to the limitations of the method above and will not be repeated here. The present application provides a fluid-solid coupling fast calculation system for complex fluid control systems, including:

[0065] The flow path division module is used to divide the complex fluid control system into control flow paths and supply flow paths.

[0066] The control flow path solving module is used to establish a zero-dimensional mathematical model based on the control flow path and determine corresponding solving program information according to the zero-dimensional mathematical model.

[0067] The supply flow path simulation module is used to establish a three-dimensional grid model based on the supply flow path and determine corresponding CFD numerical simulation program information according to the three-dimensional grid model.

[0068] A custom program determination module is used to determine a user-defined function program; the user-defined function program is used to: realize bidirectional fluid-solid coupling between the zero-dimensional mathematical model and the three-dimensional grid model based on the solver information and the CFD numerical simulation program information.

[0069] The fluid-structure coupling calculation module is used to compile the user-defined function program into a dynamic link library and call it to complete the fluid-structure coupling calculation within a preset time.

[0070] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Figure 3As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O) and a communication interface. The processor, memory and input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a fast fluid-solid coupling calculation method for complex fluid control systems is implemented.

[0071] Those skilled in the art will understand that Figure 3 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0072] In an exemplary embodiment, a computer device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement steps in a fast fluid-structure coupling calculation method for a complex fluid control system.

[0073] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0074] In an exemplary embodiment, a computer program product is provided, including a computer program. When the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0075] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0076] Those skilled in the art will understand that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, database or other media used in the embodiments provided in this application may include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory may include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0077] The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processors involved in the various embodiments provided herein may include, but are not limited to, general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic units, data processing logic units based on quantum computing, and the like.

[0078] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0079] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above examples is only intended to help understand the method and core concept of this application. At the same time, for those skilled in the art, based on the concept of this application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A fast calculation method for fluid-structure coupling in complex fluid control systems, characterized in that: The method comprises: Divide the complex fluid control system into control flow path and supply flow path; Establishing a zero-dimensional mathematical model based on the control flow path, and determining corresponding solution program information according to the zero-dimensional mathematical model; Establishing a three-dimensional grid model based on the supply flow path, and determining corresponding CFD numerical simulation program information according to the three-dimensional grid model; Determining a user-defined function program; wherein the user-defined function program is used to: realize bidirectional fluid-solid coupling between the zero-dimensional mathematical model and the three-dimensional grid model based on the solver information and the CFD numerical simulation program information; The solver information of the zero-dimensional mathematical model is compiled into a dynamic link library and a static link library, and then the user-defined function program is loaded through external compilation to call the dynamic link library and the static link library to complete the fluid-solid coupling calculation within a preset time.

2. The fast calculation method for fluid-structure coupling of complex fluid control systems according to claim 1, characterized in that: The dynamic link library is compiled by the solution process program; the static link library is compiled by the header file; three external functions are declared in the header file, the first external function is used to implement the initialization of the flow field boundary conditions, the second external function is used to start the iterative solution at each time step to obtain the solution result and output it, and the third external function is used to save the solution result and use the solution result as the flow field initialization data for the next time step.

3. The fast calculation method for fluid-structure coupling of complex fluid control systems according to claim 2, characterized in that: The zero-dimensional mathematical model includes a flow equation and a mechanical equation; The solution process includes the following steps: According to the flow equation and the mechanical equation, a dynamic balance differential equation and a dynamic model of each component are established; Determine the dynamic partial differential equations according to the dynamic balance differential equations and dynamic models of each component; Discretizing the dynamic partial differential equations to obtain a difference equation; The differential equation is solved according to the flow field boundary conditions to obtain a solution result; the solution result includes the moving pressure of each component in the next time step and the position of the current time step.

4. The fast calculation method for fluid-structure coupling of complex fluid control systems according to claim 1, characterized in that: Establishing a three-dimensional grid model based on the supply flow path includes: Dividing the supply flow path into a valve core movement area and a stationary area; According to a first preset setting condition, the static area is established as an unstructured grid; According to a second preset setting condition, the valve core movement area is established as a structured grid; the unstructured grid and the structured grid constitute a three-dimensional grid model; The first preset setting condition includes: locally densifying an area where the pressure gradient is within a preset gradient range; setting the surface where the static area intersects the valve core movement area as a static interface, and the difference between the grid size of the static interface and the grid size of the valve core movement area is within a preset size range; The second preset setting condition includes: the surface where the valve core movement area intersects the static area is set as the movement interface, and the difference between the grid size of the movement interface and the grid size of the static area is within a preset size range; the grid height of the valve core movement area matches the movement speed.

5. The fast calculation method for fluid-structure coupling of complex fluid control systems according to claim 4, characterized in that: The CFD numerical simulation program information includes the following steps: The unstructured grid and the structured grid are imported into Fluent software, and a turbulence model, a heat transfer model, and a multiphase flow model are set. The grid boundary conditions and physical property parameters are set, and the grids of the stationary interface and the moving interface are matched one-to-one. The flow field initialization data of the current time step is obtained as the data basis for updating the grid of the three-dimensional grid model.

6. The fast calculation method for fluid-structure coupling of complex fluid control systems according to claim 1, characterized in that: The data processing process of the user-defined function program at each time step includes the following steps: Collecting the flow field boundary conditions that affect the zero-dimensional calculation in the current time step flow field; the flow field boundary conditions that affect the zero-dimensional calculation are calculated by the three-dimensional grid model; Based on the flow field boundary conditions and the solver information, an iterative solution is performed to obtain a solution result; the solution result includes the moving pressure of each component in the next time step and the position of the current time step; Establish the force balance differential equation of valve core motion; Based on the force balance differential equation, according to the solution result and the flow field boundary conditions, calculating the movement speed of the valve core in the next time step; The moving speed is fed back to the three-dimensional grid model to perform grid update, and an updated flow field boundary condition is obtained, and then the iteration of the next time step is entered according to the updated flow field boundary condition.

7. The fast calculation method for fluid-structure coupling of complex fluid control systems according to claim 1, characterized in that: The user-defined function program is loaded by external compilation to call the dynamic link library and the static link library to complete the fluid-structure interaction calculation within a preset time, including: Compile an initial UDF program using Fluent software to obtain a libudf folder; the libudf folder includes a src folder and a lnamd64 folder; the lnamd64 folder includes a 3ddp_host folder and a 3ddp_node folder; Save the user-defined function program to the src folder; Save the .so file to the same root directory of the libudf folder, and save the .a file to the 3ddp_hope folder and the 3ddp_node folder respectively; wherein, the .so file refers to the dynamic link library, and the .a file refers to the static link library; Reset the compilation environment using the make clean command, then use the make command to recompile all files in the same root directory of the modified libudf folder. Mount the recompiled files into the Fluent software and click Load to complete the call of the user-defined function program and start the fluid-structure interaction calculation for the preset duration.

8. The fast calculation method for fluid-structure coupling of complex fluid control systems according to claim 7, characterized in that: The user-defined function program is saved in the src folder, including: Rename the user-defined function program to the name of the program in the src folder and overwrite the program in the src folder.

Images