Universal prediction method, system, equipment and medium for flow field of hydraulic headbox

Abstract

The invention provides a hydraulic headbox flow field general prediction method, system, equipment and medium, and the method comprises the steps: S1, constructing a geometric model of a hydraulic headbox, dividing the hydraulic headbox into different flowing parts in a fluid flowing direction according to the geometric model, building a fluid domain model for each flowing part, obtaining a fluid domain model corresponding to each flowing part; performing grid division on each fluid domain model; and S2, performing analogue simulation calculation on each fluid domain model after grid division, taking the analogue calculation result of the previous fluid domain model as the boundary condition of the next fluid domain model along the fluid flowing direction, and obtaining the flow field data of each fluid domain model after the analogue simulation calculation of all the fluid domain models is completed. According to the method, the flow field distribution condition in each flowing part of the hydraulic headbox can be accurately predicted.

Description

Technical Field

[0001] The invention relates to a general prediction method, system, equipment and medium for a hydraulic headbox flow field based on numerical simulation. Background Art

[0002] Toilet paper is an important part of household paper, accounting for more than 46% of the total household paper in 2023. With the continuous improvement of living standards, consumers' requirements for the quality of toilet paper are also increasing.

[0003] The headbox is a key equipment in the production process of toilet paper, and the uniformity of its spraying is one of the key factors affecting the quality of toilet paper production. The experimental method to test the uniformity of the headbox spraying is highly reliable and can intuitively reflect the actual situation. However, due to the large scale of the headbox itself, the experimental method is costly, high-cost and time-consuming to study its flow field and spraying uniformity, which is not conducive to the rapid optimization and iteration of the headbox structure. Compared with the experimental method, the numerical simulation method has the characteristics of low cost and short cycle, and can speed up the optimization and iteration of the headbox structure. However, there are few studies on the flow field simulation of the whole headbox, and it is impossible to obtain the specific information of the flow field of each part of the internal flow field during the operation of the headbox. In addition, there is no general model for the internal flow field simulation of the hydraulic headbox in the current public literature, which limits the application efficiency of the numerical simulation method in the field of hydraulic headbox. Summary of the invention

[0004] In order to solve the above problems of the prior art, the present invention provides a general prediction method, system, device and medium for flow field of a hydraulic headbox, which can realize accurate prediction of flow field distribution in each flow part of the hydraulic headbox.

[0005] The present invention is achieved through the following technical solutions: In a first aspect, the present invention provides a general prediction method for a flow field of a hydraulic headbox, comprising: S1, constructing a geometric model of a hydraulic headbox, dividing the hydraulic headbox into different flow parts along the fluid flow direction according to the geometric model, establishing a fluid domain model for each flow part, and obtaining a fluid domain model corresponding to each flow part; meshing each fluid domain model; S2, simulate and calculate each fluid domain model after meshing, wherein, along the fluid flow direction, the simulation calculation result of the previous fluid domain model is used as the boundary condition of the next fluid domain model. After the simulation calculation of all fluid domain models is completed, the flow field data of each fluid domain model is obtained.

[0006] Preferably, along the fluid flow direction, the flow parts are, in sequence, the headbox main pipe and headbox branch pipes, the turbulence generator, and the lip; or, the flow parts are, in sequence, the headbox main pipe and headbox branch pipes, the turbulence generator, the rectifying chamber, and the lip.

[0007] Further, the hydraulic headbox has multiple rows of turbulence generators, and the multiple rows of turbulence generators are arranged non-parallelly. Fluid domain models are respectively established for the turbulence generators with different arrangement angles.

[0008] Further, in the fluid domain model of the headbox main pipe and headbox branch pipes, surface mesh is refined for the front wall of the headbox main pipe and the headbox branch pipe part; in the fluid domain model of the turbulence generator, volume mesh is refined for the sudden expansion part of the flow cross-section of the turbulence generator and boundary layer mesh is added; in the fluid domain model of the lip, volume mesh is refined for the outlet area of the lip and boundary layer mesh is added.

[0009] Further, the hydraulic headbox has multiple rows of headbox branch pipes. When performing simulation calculation on the fluid domain model of the headbox main pipe and headbox branch pipes, the outlet with the flow rate closest to the average flow rate of each row of headbox branch pipes is found from each row of headbox branch pipes, and the velocity distribution data of the found outlet is used as the simulation calculation result of the corresponding row of headbox branch pipes.

[0010] Further, when performing simulation calculation on the fluid domain model of the headbox main pipe and headbox branch pipes, the RNG k-ε model is adopted; when performing simulation calculation on the fluid domain model of the turbulence generator, the standard k-ε model is adopted; when performing simulation calculation on the fluid domain model of the lip, the realizable k-ε model is adopted.

[0011] Preferably, for the pulp with a mass concentration less than or equal to 1.5%, water is used as the fluid material for simulation calculation; for the pulp with a mass concentration greater than 1.5%, the Mixture multiphase flow model is used for simulation calculation.

[0012] In a second aspect, the present invention provides a general prediction system for the flow field of a hydraulic headbox, including: A model construction module, configured to construct a geometric model of the hydraulic headbox, divide the hydraulic headbox along the fluid flow direction into different flow parts, respectively establish fluid domain models for each flow part to obtain the fluid domain models respectively corresponding to each flow part; perform mesh division on each fluid domain model; A simulation calculation module, configured to perform simulation calculation on each fluid domain model after mesh division respectively, wherein, along the fluid flow direction, the simulation calculation result of the previous fluid domain model is used as the boundary condition of the subsequent fluid domain model. After the simulation calculation of all fluid domain models is completed, the flow field data of each fluid domain model is obtained.

[0013] In a third aspect, the present invention provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the general prediction method for the flow field of a hydraulic headbox as described above is implemented.

[0014] In a fourth aspect, the present invention provides a computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the general prediction method for the flow field of a hydraulic headbox as described above is implemented.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention models the hydraulic headbox by dividing it into different flow parts to obtain fluid domain models corresponding to each flow part respectively, then performs mesh generation and simulation calculation on each fluid domain model respectively, and uses the simulation calculation result of the previous flow part as the boundary condition of the next flow part. The present invention avoids establishing a complex overall fluid domain model of the hydraulic headbox, greatly reduces the complexity of the simulation calculation for the hydraulic headbox, improves the mesh quality, and reduces the hardware requirements for the simulation calculation of the hydraulic headbox. The present invention predicts the full-process flow field of the hydraulic headbox by means of simulation calculation of flow parts separately, can analyze and evaluate the uniformity of each flow part respectively, and provides a reference for the design optimization of each flow part. The present invention can predict the internal flow field uniformity and pulp flow distribution characteristics of each flow part of a new product of the hydraulic headbox in the early stage of design, provides a product design basis for the designers of the hydraulic headbox, avoids repeated experimental tests, shortens the development cycle of new products, and reduces the human and material costs.

[0016] Further, for a headbox with multiple rows of turbulence generators and the turbulence generators in each row are not arranged in parallel, different arrangement angles of the turbulence generators in each row will result in different outlet velocity distributions. Modeling and calculating the turbulence generators with different arrangement angles respectively and then importing them into the lip plate inlet of the corresponding row can further improve the accuracy of the prediction results. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 It is a geometric model diagram of the hydraulic headbox prototype in the embodiment.

[0019] Figure 2 It is a fluid domain model diagram of the main pulp distribution pipe and the branch pulp distribution pipes established based on the hydraulic headbox prototype in the embodiment.

[0020] Figure 3 It is a fluid domain model diagram of the turbulence generator established based on the hydraulic headbox prototype in the embodiment.

[0021] Figure 4 It is a fluid domain model diagram of the lip plate established based on the hydraulic headbox prototype in the embodiment.

[0022] Figure 5 It is a broken line graph (a) of the average flow rate distribution of each column of the branch pulp distribution pipes of the main pulp distribution pipe of the hydraulic headbox and a broken line graph (b) of the lateral pressure and velocity distribution at the lip plate outlet in the embodiment. Specific implementation mode

[0023] The following uses specific specific examples to illustrate the implementation mode of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0024] It should be noted that the process equipment or devices not specifically specified in the following embodiments all adopt conventional equipment or devices in the art.

[0025] It should be noted that the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices. Moreover, unless otherwise specified, the numbers of the method steps are only convenient tools for identifying the method steps, rather than limiting the arrangement order of the method steps or the scope in which the present invention can be implemented. The change or adjustment of their relative relationship, without substantial change in the technical content, should also be regarded as the scope in which the present invention can be implemented.

[0026] The general flow field prediction method for the hydraulic headbox described in the present invention includes: S1, constructing a geometric model of the hydraulic headbox, dividing the hydraulic headbox into different flow parts along the fluid flow direction according to the geometric model, respectively establishing fluid domain models for each flow part to obtain the fluid domain models corresponding to each flow part; performing grid division on each fluid domain model.

[0027] Since a hydraulic headbox is often relatively large in overall scale, directly performing an overall modeling will lead to problems such as a huge number of grids and too low grid quality during subsequent grid division, resulting in the inability to perform subsequent simulation calculations. Therefore, when establishing the fluid domain model of the present invention, the hydraulic headbox is split into different flow parts along the fluid flow direction for separate modeling, and during subsequent simulation calculations, the fluid domain models corresponding to each flow part are calculated in sequence. The simulation calculation results of the previous flow part are used as the boundary conditions for the simulation calculation of the subsequent flow part, so as to realize the flow field prediction of the entire hydraulic headbox.

[0028] Specifically, the hydraulic headbox can be split into the following flow parts: a distributing main pipe and distributing branch pipes with an arched cross-section or a rectangular cross-section, a turbulence generator, and a lip plate. Here, the lip plate is the collective name of the upper lip plate and the lower lip plate. There are also some hydraulic headboxes designed with a rectifying chamber. After the pulp flows out of the distributing branch pipes, it enters the rectifying chamber, and then flows through the turbulence generator and finally flows through the lip plate and sprays onto the wire through the lip orifice. In the embodiments of the present invention, a hydraulic headbox without a rectifying chamber is taken as an example for illustration. Since heat transfer does not need to be considered when calculating the pulp flow, it is only necessary to model the fluid domains of each flow part. For a headbox with multiple rows of distributing branch pipes and the turbulence generators in each row not arranged in parallel, it is necessary to separately model and calculate the turbulence generators with different arrangement angles. In addition, during the modeling process, if there is a rectifying chamber, each outlet of the rectifying chamber and each inlet of the lip plate need to be named separately; if there is no rectifying chamber, each outlet of the distributing branch pipes of the distributing main pipe and each inlet of the lip plate need to be named separately, so as to facilitate uniformity analysis and subsequent calculation settings.

[0029] Perform grid division on the fluid domain models of each flow part of the constructed hydraulic headbox. The following are the parts that need special attention during the grid division process: When performing grid division on the distributing main pipe and distributing branch pipes, it is necessary to perform surface grid encryption on the front wall of the distributing main pipe of the distributing branch pipes and the grids of the distributing branch pipes; when performing grid division on the turbulence generator, it is necessary to perform volume grid encryption on the local part where the flow cross-section has a sudden expansion, and at the same time, it is necessary to add a flow boundary layer grid; when performing grid division on the lip plate part, it is necessary to perform volume grid encryption on the part close to the nozzle and add a flow boundary layer grid. The maximum distortion of the divided grids needs to be less than 0.7, and the minimum orthogonal grid quality needs to be greater than 0.15. If the conditions are met, it is considered that it can be used for subsequent simulation calculations.

[0030] S2. Perform simulation calculations on each fluid domain model after grid division. Among them, along the fluid flow direction, the simulation calculation results of the previous fluid domain model are used as the boundary conditions for the subsequent fluid domain model. After all the fluid domain models are completed with simulation calculations, the flow field data of each fluid domain model are obtained.

[0031] S21. Import the fluid domain model with the divided grid into ANSYS Fluent for parameter settings: (1) Material settings: For pulp with a mass concentration less than 1.5%, since its material parameters such as density and viscosity are close to those of water, water can be directly used as the fluid material for simulation calculations. For pulp with a larger mass concentration, the Mixture multiphase flow model needs to be used. Set water in the pulp suspension as the main phase and continuous phase, and fibers as the secondary phase and discontinuous phase. The parameters such as the density and viscosity of the fibers need to be set after actual measurement.

[0032] (2) Turbulence model selection: When performing simulation calculations on the fluid domain models of the main pulp distribution pipe and the branch pulp distribution pipes, the RNG k-ε model is selected; when performing simulation calculations on the fluid domain model of the turbulence generator, the standard k-ε model is selected; when performing simulation calculations on the fluid domain model of the lip plate, the Realizable k-ε model is selected.

[0033] (3) Boundary condition settings: When performing simulation calculations on the fluid domain models of the main pulp distribution pipe and the branch pulp distribution pipes, set the inlet of the main pulp distribution pipe as the mass flow inlet boundary condition, set the return end of the main pulp distribution pipe as the mass flow outlet boundary condition, and set the outlets of each branch pulp distribution pipe as the outflow boundary (Outflow); when performing simulation calculations on the fluid domain model of the turbulence generator, set the inlet of the turbulence generator as the velocity inlet boundary condition and set the outlet of the turbulence generator as the outflow boundary; when performing simulation calculations on the fluid domain model of the lip plate, set the inlet of the lip plate as the velocity inlet boundary condition and set the outlet of the lip plate as the pressure outlet condition.

[0034] S22. After the parameter settings are completed, start the steady-state simulation calculations on the fluid domain models of each flow part in sequence. When each residual is less than 10e -4 it can be considered that the simulation calculation results have converged. First, perform simulation calculations on the main pulp distribution pipe and the branch pulp distribution pipes, and export the outlet flow rate data of each branch pulp distribution pipe in the simulation calculation results. Find the outlet with the flow rate closest to the average flow rate of the branch pulp distribution pipes and export its outlet velocity distribution data in the form of a profile file; then perform simulation calculations on the turbulence generator, import the profile file exported from the simulation calculation of the main pulp distribution pipe into the velocity inlet boundary condition of the fluid domain model of the turbulence generator, and use the same method to export the outlet velocity distribution data in the calculation results of the turbulence generator as the velocity inlet boundary condition of the lip plate to perform the simulation calculation of the internal flow field of the lip plate.

[0035] Based on the results of the simulation calculations for each flowing part, the pulp flow uniformity of the hydraulic headbox for which the flow field simulation is carried out is analyzed and evaluated, including the pressure distribution uniformity of the main pulp distribution pipe, the flow rate uniformity of each pulp distribution branch pipe, the velocity uniformity at the outlet of the turbulence generator, the velocity uniformity of the lip spraying on the cross direction of the lip plate, etc., and whether further improvement design is needed is considered according to the analysis results.

[0036] Embodiment 1. Establish a fluid domain model for each flowing part and perform mesh division In the embodiment of the present invention, a hydraulic headbox without a rectifying chamber is taken as an example, and its geometric model diagram is as Figure 1 shown. The geometric model of the hydraulic headbox includes components such as the main pulp distribution pipe and pulp distribution branch pipes, the turbulence generator frame, the turbulence generator, the support plate, the side wall plates, the upper and lower lip plates, the clamping plates, and the floating pieces inside the lip plate. Among them, the parts related to the fluid domain are the main pulp distribution pipe and pulp distribution branch pipes, the turbulence generator, the lip plate, and the floating pieces. Here, the lip plate is the collective name of the upper lip plate and the lower lip plate. Since the simulation calculation cannot simulate the working process of the floating pieces, the floating pieces need to be ignored when establishing the fluid domain model. When establishing the fluid domain model, the outlets of each pulp distribution branch pipe of the main pulp distribution pipe and the inlets of each lip plate flow domain are independently named. Figure 2 、 Figure 3 、 Figure 4 They are respectively the fluid domain model diagrams of the main pulp distribution pipe and pulp distribution branch pipes, the turbulence generator, and the lip plate established according to the prototype geometric model. Subsequently, the established fluid domain model is meshed in Fluent Meshing. The surface mesh of the front wall of the main pulp distribution pipe and the pulp distribution branch pipe part is encrypted, the volume mesh of the sudden expansion part of the flow cross-section of the turbulence generator is encrypted and boundary layer meshes are added, and the volume mesh of the area near the outlet of the lip plate fluid domain is encrypted and boundary layer meshes are added.

[0037] 2. Simulation calculation In this embodiment, the mass concentration of the pulp is 0.15%, which is less than 1.5%. Therefore, water can be directly used as the fluid material for simulation calculation.

[0038] (1) Fluid domain model of the main pulp distribution pipe and pulp distribution branch pipes When performing simulation calculation on the fluid domain model of the main pulp distribution pipe and pulp distribution branch pipes, the RNG k-ε model is used for the turbulence model. The inlet end and the reflux end of the main pulp distribution pipe are both flow inlet boundary conditions, and the flow rates are 588.7 kg / s and 41.2 kg / s respectively. The outlets of each pulp distribution branch pipe are outflow boundaries. The convergence condition is that each residual value is less than 10e -4, after the calculation converges, the outlet flow rate data of each pulp distribution branch pipe are exported for subsequent uniformity analysis and evaluation. In this embodiment, there are four rows of pulp distribution branch pipes. It is necessary to find the outlet with the flow rate closest to the average flow rate of this row of pulp distribution branch pipes from the outlets of each row of pulp distribution branch pipes and export the outlet velocity distribution data in the form of a profile file respectively.

[0039] (2)Fluid domain model of the turbulence generator When performing simulation calculations on the fluid domain model of the turbulence generator, in the embodiment, the arrangement angles of each row of turbulence generators are different, and simulation calculations need to be performed for four angle cases respectively. The standard k-ε model is used for the turbulence model. The profile files exported from the simulation calculation results of the fluid domain models of the pulp distribution main pipe and the pulp distribution branch pipes are respectively imported into the case of the turbulence generator corresponding to the number of rows as the velocity inlet boundary conditions for simulation calculations. After the calculation converges, the outlet velocity distribution data of the turbulence generators at four angles are also exported in the form of profile files, integrated, and used as the velocity inlet boundary conditions of the lip plate.

[0040] (3)Fluid domain model of the lip plate When performing simulation calculations on the fluid domain model of the lip plate, the realizable k-ε model is used for the turbulence model. The profile files obtained by exporting and integrating the simulation calculation results of the fluid domain model of the turbulence generator are used as the velocity inlet boundary conditions for each inlet of the fluid domain model of the lip plate. After iterative calculation converges, all simulation calculations are completed.

[0041] 3. Analyze and evaluate the hydraulic headbox according to the simulation calculation results of each fluid domain model Figure 5 It is the line graph of the average flow rate distribution of each row of pulp distribution branch pipes of the pulp distribution main pipe and the line graph of the transverse pressure and velocity distribution at the lip plate outlet. By viewing the data such as the velocity and pressure nephograms, outlet flow rate and velocity distribution of each fluid domain model, analyze and evaluate the working performance of each part of the designed hydraulic headbox. Then, ideas can be provided for the further optimization design of the hydraulic headbox according to the analysis results.

[0042] The following is the device embodiment of the present invention, which can be used to execute the method embodiment of the present invention. For the details not disclosed in the device embodiment, please refer to the method embodiment of the present invention.

[0043] In another embodiment of the present invention, a general prediction system for the flow field of a hydraulic headbox is provided, which can be used to implement the above-mentioned general prediction method for the flow field of a hydraulic headbox. Specifically, the general prediction system for the flow field of a hydraulic headbox includes: A model construction module, configured to construct a geometric model of a hydraulic headbox, divide the hydraulic headbox into different flow parts along the fluid flow direction according to the geometric model, establish fluid domain models for each flow part respectively, and obtain the fluid domain models corresponding to each flow part respectively; perform mesh division on each fluid domain model; A simulation calculation module, configured to perform simulation calculations on each fluid domain model after mesh division respectively. Among them, along the fluid flow direction, the simulation calculation result of the previous fluid domain model is used as the boundary condition of the subsequent fluid domain model. After the simulation calculations of all fluid domain models are completed, the flow field data of each fluid domain model is obtained.

[0044] In another embodiment of the present invention, a computer device is provided. The computer device includes a processor and a memory. The memory is used to store a computer program. The computer program includes program instructions. The processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, and is suitable for implementing one or more instructions. Specifically, it is suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function; the processor described in the embodiment of the present invention can be used for the operation of the general prediction method for the flow field of a hydraulic headbox.

[0045] In another embodiment of the present invention, the present invention further provides a storage medium, specifically a computer-readable storage medium (Memory). The computer-readable storage medium is a memory device in a computer device and is used to store programs and data. It can be understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and, of course, the extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space, and the operating system of the terminal is stored in this storage space. Moreover, one or more instructions suitable for being loaded and executed by the processor are also stored in this storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a random access memory (Random Access Memory, RAM), or a non-volatile memory, such as at least one disk memory. One or more instructions stored in the computer-readable storage medium can be loaded and executed by the processor to implement the corresponding steps of the general prediction method for the flow field of the hydraulic headbox in the above embodiments.

[0046] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, optical memories, etc.) containing computer-usable program codes.

[0047] The present invention is described with reference to the flowcharts and / or block diagrams of methods, systems (devices), and computer program products according to the embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0048] These computer program instructions can 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 generate a manufactured article including an instruction device, and the instruction device implements the functions in the flow Figure 1one process or multiple processes and / or boxes Figure 1 the functions specified in one box or multiple boxes.

[0049] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in Figure 1 one process or multiple processes and / or boxes Figure 1 the functions specified in one box or multiple boxes.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications or equivalent replacements can still be made to the specific implementation manners of the present invention. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A general prediction method for the flow field of a hydraulic headbox, characterized in that Including: S1. Construct a geometric model of a hydraulic headbox. Divide the hydraulic headbox into different flow parts along the fluid flow direction according to the geometric model, establish fluid domain models for each flow part respectively, and obtain the fluid domain models corresponding to each flow part; perform mesh division on each fluid domain model. S2. Perform simulation calculations on each fluid domain model after mesh division. Among them, along the fluid flow direction, the simulation calculation results of the previous fluid domain model are used as the boundary conditions of the subsequent fluid domain model. After the simulation calculations of all fluid domain models are completed, the flow field data of each fluid domain model are obtained.

2. The general prediction method for the flow field of a hydraulic headbox according to claim 1, wherein Along the fluid flow direction, each flow part is, in sequence, a stock distribution main pipe and stock distribution branch pipes, a turbulence generator, and a lip plate; or each flow part is, in sequence, a stock distribution main pipe and stock distribution branch pipes, a turbulence generator, a rectifying chamber, and a lip plate.

3. The general prediction method for the flow field of a hydraulic headbox according to claim 2, characterized in that The hydraulic headbox has multiple rows of turbulence generators, and the multiple rows of turbulence generators are arranged non-parallelly. Fluid domain models are established for the turbulence generators with different arrangement angles respectively.

4. The general prediction method for the flow field of a hydraulic headbox according to claim 2, characterized in that, In the fluid domain model of the stock distribution main pipe and stock distribution branch pipes, surface mesh is refined for the front wall of the stock distribution main pipe and the stock distribution branch pipe part; in the fluid domain model of the turbulence generator, volume mesh is refined for the sudden expansion part of the flow cross-section of the turbulence generator and boundary layer mesh is added; in the fluid domain model of the lip plate, volume mesh is refined for the outlet area of the lip plate and boundary layer mesh is added.

5. The general prediction method for the flow field of a hydraulic headbox according to claim 2, characterized in that The hydraulic headbox has multiple rows of stock distribution branch pipes. When performing simulation calculations on the fluid domain model of the stock distribution main pipe and stock distribution branch pipes, find the outlet with the flow rate closest to the average flow rate of each row of stock distribution branch pipes from each row of stock distribution branch pipes, and use the velocity distribution data of the found outlet as the simulation calculation results of the corresponding row of stock distribution branch pipes.

6. The general prediction method for the flow field of a hydraulic headbox according to claim 2, characterized in that When performing simulation calculations on the fluid domain model of the stock distribution main pipe and stock distribution branch pipes, the RNG k-ε model is used; when performing simulation calculations on the fluid domain model of the turbulence generator, the standard k-ε model is used; when performing simulation calculations on the fluid domain model of the lip plate, the realizable k-ε model is used.

7. The general prediction method for the flow field of a hydraulic headbox according to claim 1, characterized in that For pulp with a mass concentration less than or equal to 1.5%, water is used as the fluid material for simulation calculations; for pulp with a mass concentration greater than 1.5%, the Mixture multiphase flow model is used for simulation calculations.

8. A general prediction system for the flow field of a hydraulic headbox, characterized in that, Including: A model construction module for constructing a geometric model of a hydraulic headbox, dividing the hydraulic headbox into different flow parts along the fluid flow direction according to the geometric model, establishing fluid domain models for each flow part respectively, obtaining the fluid domain models corresponding to each flow part; performing mesh division on each fluid domain model. A simulation calculation module for performing simulation calculations on each fluid domain model after mesh division. Among them, along the fluid flow direction, the simulation calculation results of the previous fluid domain model are used as the boundary conditions of the subsequent fluid domain model. After the simulation calculations of all fluid domain models are completed, the flow field data of each fluid domain model are obtained.

9. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the general prediction method for the flow field of a hydraulic headbox according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the general prediction method for the flow field of a hydraulic headbox according to any one of claims 1 to 7.

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