Flow field simulation methods, devices, non-volatile storage media, and computer equipment

Abstract

This invention discloses a flow field simulation method, apparatus, non-volatile storage medium, and computer device. The method includes: acquiring a first three-dimensional model and a second three-dimensional model, wherein the first three-dimensional model includes a three-dimensional model of an exhaust manifold, and the second three-dimensional model includes a three-dimensional model of a cylinder assembly connected to the exhaust manifold; acquiring multiple sets of transient boundary conditions for the cylinder assembly in multiple consecutive time steps; and performing transient simulation of the flow field corresponding to the exhaust manifold based on the first three-dimensional model, the second three-dimensional model, and the multiple sets of transient boundary conditions to obtain flow field simulation data. This invention solves the technical problem of the inability to accurately simulate the flow field in an exhaust manifold.

Description

Technical Field

[0001] This invention relates to the field of computer-aided design, and more specifically, to a flow field simulation method, apparatus, non-volatile storage medium, and computer equipment. Background Technology

[0002] As the automotive market continues to grow, people's car-buying concepts are becoming more sophisticated, and they are paying more and more attention to various performance indicators of automobiles. As the most important component of a car, the performance of the engine has a decisive impact on the car's power and fuel economy. As another important component of the engine, the exhaust manifold's gas flow performance also has a significant impact on the overall engine output power and cycle thermal efficiency.

[0003] However, during an engine's working cycle, the positions of its various internal components change in real time, and the flow field within the exhaust manifold is quite complex. In related technologies, steady-state simulation is usually used to study the flow field within the exhaust manifold. However, the calculation results cannot reflect the actual flow of fluid within the exhaust manifold, leading to a certain degree of blindness in the subsequent design of the exhaust manifold. This can result in phenomena such as "cross-flow" in the exhaust manifold that affect the overall exhaust performance.

[0004] There is currently no effective solution to the above problems. Summary of the Invention

[0005] This invention provides a flow field simulation method, apparatus, non-volatile storage medium, and computer device to at least solve the technical problem of the inability to accurately simulate the flow field in an exhaust manifold.

[0006] According to one aspect of the present invention, a flow field simulation method is provided, comprising: acquiring a first three-dimensional model and a second three-dimensional model, wherein the first three-dimensional model includes a three-dimensional model of an exhaust manifold, and the second three-dimensional model includes a three-dimensional model of a cylinder assembly connected to the exhaust manifold; acquiring multiple sets of transient boundary conditions of the cylinder assembly in multiple consecutive time steps; and performing transient simulation on the flow field corresponding to the exhaust manifold based on the first three-dimensional model, the second three-dimensional model, and the multiple sets of transient boundary conditions to obtain flow field simulation data of the flow field.

[0007] Optionally, the step of performing transient simulation on the flow field corresponding to the exhaust manifold based on the first three-dimensional model, the second three-dimensional model, and the multiple sets of transient boundary conditions to obtain the flow field simulation data includes: determining the positional relationship between the first three-dimensional model and the second three-dimensional model and the flow field boundary conditions of the flow field in the time step corresponding to each set of transient boundary conditions based on the transient boundary conditions; determining the initial boundary conditions of the flow field in the current time step corresponding to any set of transient boundary conditions based on the first three-dimensional model, the second three-dimensional model, the positional relationship, and the flow field boundary conditions; and performing transient simulation on the flow field based on the initial boundary conditions and the first simulation result of the flow field in the previous time step of the current time step to obtain the flow field simulation data.

[0008] Optionally, the step of performing transient simulation on the flow field based on the initial boundary conditions and the first simulation result of the flow field in the previous time step to obtain the flow field simulation data includes: determining the first volume grid corresponding to the flow field in the previous time step, wherein the first simulation result includes the first volume grid, and the first volume grid is a volume grid used for simulating and calculating the flow field; adjusting the first volume grid according to the initial boundary conditions to obtain a second volume grid; and performing transient simulation on the flow field based on the second volume grid to obtain the flow field simulation data.

[0009] Optionally, adjusting the first volume mesh according to the initial boundary conditions to obtain the second volume mesh includes: when the cylinder assembly includes a first component and the first component constitutes the outer surface of the flow field, determining that the initial boundary conditions include the shape and size of the first space formed by the first component and the exhaust manifold; and stretching or compressing the mesh in the first volume mesh corresponding to the first space according to the shape and size of the first space to obtain the second volume mesh.

[0010] Optionally, adjusting the first volume mesh according to the initial boundary conditions to obtain the second volume mesh further includes: when the cylinder assembly includes a second component and the second component is located inside the flow field, determining that the initial boundary conditions include a first position of the second component in the flow field, the first volume mesh including a flow field volume mesh and a component volume mesh corresponding to the second component, the flow field volume mesh having the attribute of a background domain volume mesh, and the component volume mesh having the attribute of a superimposed domain volume mesh; determining a second position of the component volume mesh in the flow field volume mesh; and when the positional deviation between the first position and the second position exceeds a deviation threshold, moving the component volume mesh in the first volume mesh to the first position to obtain the second volume mesh, wherein the second volume mesh includes the flow field volume mesh and the component volume mesh moved to the first position.

[0011] Optionally, obtaining multiple sets of transient boundary conditions for the cylinder assembly at multiple consecutive moments includes: performing one-dimensional thermodynamic simulation on the cylinder assembly to obtain the multiple sets of transient boundary conditions, wherein the multiple sets of transient boundary conditions include the position of the cylinder assembly, the flow field boundary pressure and the flow field boundary temperature of the exhaust manifold.

[0012] Optionally, the cylinder assembly includes at least one of the following: a piston of the cylinder, and a valve of the cylinder.

[0013] According to another aspect of the present invention, a flow field simulation device is also provided, comprising: a first acquisition module, configured to acquire a first three-dimensional model and a second three-dimensional model, wherein the first three-dimensional model includes a three-dimensional model of an exhaust manifold, and the second three-dimensional model includes a three-dimensional model of a cylinder assembly connected to the exhaust manifold; a second acquisition module, configured to acquire multiple sets of transient boundary conditions of the cylinder assembly at multiple consecutive moments; and a simulation module, configured to perform transient simulation on the flow field corresponding to the exhaust manifold based on the first three-dimensional model, the second three-dimensional model, and the multiple sets of transient boundary conditions, to obtain flow field simulation data of the flow field.

[0014] According to another aspect of the present invention, a non-volatile storage medium is also provided, the non-volatile storage medium including a stored program, wherein, when the program is executed, the device where the non-volatile storage medium is located is controlled to execute any of the above-described flow field simulation methods.

[0015] According to another aspect of the present invention, a computer device is also provided, the computer device including a processor, the processor being configured to run a program, wherein the program, when running, executes any of the flow field simulation methods described above.

[0016] In this embodiment of the invention, by acquiring a first three-dimensional model and a second three-dimensional model, wherein the first three-dimensional model includes a three-dimensional model of the exhaust manifold and the second three-dimensional model includes a three-dimensional model of the cylinder assembly connected to the exhaust manifold; acquiring multiple sets of transient boundary conditions of the cylinder assembly in multiple consecutive time steps; and performing transient simulation on the flow field corresponding to the exhaust manifold based on the first three-dimensional model, the second three-dimensional model, and the multiple sets of transient boundary conditions, the flow field simulation data of the flow field is obtained. This achieves the purpose of incorporating the influence of the movement of the cylinder assembly connected to the exhaust manifold on the flow field within the exhaust manifold into the flow field simulation process, thereby achieving the technical effect of improving the accuracy of the flow field simulation results and solving the technical problem of being unable to accurately simulate the flow field in the exhaust manifold. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0018] Figure 1 A hardware structure block diagram of a computer terminal for implementing a flow field simulation method is shown.

[0019] Figure 2 This is a flowchart illustrating the flow field simulation method provided according to an embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of a first three-dimensional model and a second three-dimensional model provided according to an optional embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of a deformable dynamic mesh method for simulating piston motion according to an optional embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of a background domain volume mesh and an overlay domain volume mesh partitioning method provided by an optional embodiment of the present invention;

[0023] Figure 6 This is a schematic diagram of a superimposed dynamic mesh method for mimicking valve movement according to an optional embodiment of the present invention;

[0024] Figure 7 This is a schematic diagram of a manifold cross-section division method provided by an optional embodiment of the present invention;

[0025] Figure 8 This is a schematic diagram of a visualized fluid simulation result provided by an optional embodiment of the present invention;

[0026] Figure 9 This is a structural block diagram of the flow field simulation device provided according to an embodiment of the present invention. Detailed Implementation

[0027] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0028] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0029] First, some nouns or terms that appear in the description of the embodiments of this application shall be interpreted as follows:

[0030] Computational Fluid Dynamics (CFD) is a science that uses computers as tools and applies various discretization mathematical methods to conduct numerical experiments, computer simulations, and analysis on various problems in fluid mechanics.

[0031] GT-SUITE software is a suite of multiphysics simulation analysis software, mainly used in fields such as vehicle driving system analysis, thermal management system analysis, engine simulation analysis, and multibody dynamics analysis.

[0032] STARCCM+ is a computational fluid dynamics software that combines numerical techniques of continuum mechanics with modern software engineering techniques for thermal fluid analysis.

[0033] Example 1

[0034] According to an embodiment of the present invention, a method embodiment for flow field simulation is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0035] The method embodiment provided in Embodiment 1 of this application can be executed on a mobile terminal, computer terminal, or similar computing device. Figure 1 A hardware block diagram of a computer terminal used to implement a flow field simulation method is shown. Figure 1 As shown, the computer terminal 10 may include one or more processors (shown as 102a, 102b, ..., 102n in the figure) (the processor may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data. In addition, it may also include: a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of a BUS bus), a network interface, a power supply, and / or a camera. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the aforementioned electronic device. For example, computer terminal 10 may also include... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0036] It should be noted that the aforementioned one or more processors and / or other data processing circuits are generally referred to herein as "data processing circuits". These data processing circuits may be implemented wholly or partially as software, hardware, firmware, or any other combination thereof. Furthermore, the data processing circuits may be a single, independent processing module, or may be wholly or partially integrated into any other element in the computer terminal 10. As involved in the embodiments of this application, the data processing circuits serve as processor control (e.g., selection of a variable resistor termination path connected to an interface).

[0037] The memory 104 can be used to store software programs and modules of application software, such as the program instructions / data storage device corresponding to the flow field simulation method in this embodiment of the invention. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory 104, thereby realizing the flow field simulation method of the aforementioned application. The memory 104 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor, and these remote memories can be connected to the computer terminal 10 via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0038] The display may be, for example, a touchscreen liquid crystal display (LCD) that allows the user to interact with the user interface of the computer terminal 10.

[0039] Figure 2 This is a flowchart illustrating the flow field simulation method provided in an embodiment of the present invention, as shown below. Figure 2 As shown, the method includes the following steps:

[0040] Step S202: Obtain a first three-dimensional model and a second three-dimensional model, wherein the first three-dimensional model includes a three-dimensional model of the exhaust manifold, and the second three-dimensional model includes a three-dimensional model of the cylinder assembly connected to the exhaust manifold.

[0041] In this step, a first three-dimensional model and a second three-dimensional model can be created using three-dimensional drawing software. Optionally, the second three-dimensional model may include three-dimensional models of the cylinder, piston, and valves connected to the exhaust manifold. Figure 3 These are schematic diagrams of the first and second three-dimensional models provided in optional embodiments of the present invention, such as... Figure 3 As shown, when creating a 3D model using 3D drawing software, the original features of the cylinder, piston, and valve can be retained so that the 3D model can fit these components in the actual application scenario. However, the model can also be appropriately modified and simplified to reduce the amount of calculation during fluid simulation. For example, some details on the cylinder and exhaust manifold surfaces that have little impact on the flow field can be simplified.

[0042] Step S204: Obtain multiple sets of transient boundary conditions for the cylinder assembly in multiple consecutive time steps.

[0043] In this step, multiple consecutive time steps can be set according to the needs of fluid simulation, and each time step can be adjusted according to the accuracy requirements of the simulation results. For example, when the total time of multiple consecutive time steps remains constant, the shorter each time step is set, the more time steps there are, and the more accurate the fluid simulation results will be when simulating the model over the total time. Each set of transient boundary conditions can be used to describe the state of the cylinder assembly within the time step corresponding to that set of transient boundary conditions, and the influence of the state of the cylinder assembly within that time step on the boundary conditions of the flow field corresponding to the exhaust manifold.

[0044] Step S206: Based on the first three-dimensional model, the second three-dimensional model, and multiple sets of transient boundary conditions, perform transient simulation on the flow field corresponding to the exhaust manifold to obtain the flow field simulation data.

[0045] In this step, transient simulation can sequentially simulate the fluid motion in each of multiple consecutive time steps, using the simulation result of the fluid motion in the previous time step as the initial state in the next time step, iterating step by step to obtain the simulation result of the flow field corresponding to the exhaust manifold over a total time period. The aforementioned fluid refers to the material in the flow field. Specifically, the fluid in the exhaust manifold can be gas. When the exhaust manifold is connected to the cylinders of the car engine, the gas in the exhaust manifold can be discharged from the cylinders and transported into the exhaust manifold. The motion state of the fluid in the exhaust manifold can change according to the movement of the cylinder assembly; therefore, the flow field will not reach a steady state. Steady-state simulation cannot obtain accurate simulation results of the flow field. This invention uses transient simulation to simulate the fluid motion, which can obtain better simulation results.

[0046] Through the above steps, the influence of the movement of the cylinder assembly connected to the exhaust manifold on the flow field inside the exhaust manifold can be incorporated into the flow field simulation process, thereby improving the accuracy of the flow field simulation results and solving the technical problem of inaccurate fluid simulation results caused by not considering the influence of piston and valve movement on the flow field.

[0047] As an optional embodiment, obtaining multiple sets of transient boundary conditions for a cylinder assembly at multiple consecutive time points can include the following steps: performing a one-dimensional thermodynamic simulation on the cylinder assembly to obtain multiple sets of transient boundary conditions, wherein the multiple sets of transient boundary conditions include the position of the cylinder assembly, the flow field boundary pressure and flow field boundary temperature of the exhaust manifold. Specifically, GT-SUITE software can be used to perform a one-dimensional thermodynamic simulation on the cylinder connected to the exhaust manifold. Based on multiple time steps, the fluid in the cylinder is simulated to obtain multiple sets of transient boundary conditions within each time step. Each set of transient boundary conditions may include the stroke of the cylinder assembly, the relative position of the cylinder assembly to the cylinder or to the exhaust manifold, the temperature and pressure at the exhaust manifold inlet, and the temperature and pressure at the exhaust manifold outlet, etc. After obtaining the multiple sets of transient boundary conditions as one-dimensional thermodynamic simulation results, the transient boundary conditions can be exported in a suitable data format for input into fluid simulation software for further transient simulation calculations.

[0048] As an optional embodiment, the cylinder assembly may include at least one of the following: a piston of the cylinder, and a valve of the cylinder. Optionally, multiple components in the cylinder participate in the operation of the engine, affecting the fluid movement within the cylinder and the exhaust manifold. The valve can affect whether the gas in the cylinder is connected to the gas in the exhaust manifold, directly affecting whether the flow field corresponding to the exhaust manifold includes the gas in the cylinder. For example, when the valve between the cylinder and the exhaust manifold is closed, the flow field corresponding to the exhaust manifold does not include the gas in the cylinder because the two are not connected at this time; while when the valve is open, the flow field corresponding to the exhaust manifold includes the gas in the cylinder, and the gas in the cylinder will also interact with the gas in the exhaust manifold, affecting the evolution of the flow field. The movement of the piston can affect the volume of gas in the cylinder. When the cylinder is in different operating stages, the position of the piston relative to the cylinder and relative to the exhaust manifold is different. At this time, the volume of gas in the cylinder is different, and the boundary position of the flow field corresponding to the exhaust manifold will also change with the position of the piston. Among them, the piston and valve are two components that have a relatively important impact. In the above fluid simulation scheme, the cylinder components may include at least one of the piston and valve.

[0049] As an optional embodiment, transient simulation of the flow field corresponding to the exhaust manifold is performed based on a first three-dimensional model, a second three-dimensional model, and multiple sets of transient boundary conditions to obtain flow field simulation data. This can include the following steps: determining the positional relationship between the first and second three-dimensional models and the flow field boundary conditions within each time step corresponding to the transient boundary conditions; determining the initial boundary conditions of the flow field within the current time step corresponding to any set of transient boundary conditions based on the first three-dimensional model, the second three-dimensional model, the positional relationship, and the flow field boundary conditions; and performing transient simulation of the flow field based on the initial boundary conditions and the first simulation result of the flow field within the previous time step to obtain flow field simulation data. Optionally, the transient boundary conditions may include the piston position, valve position, and temperature and pressure at the exhaust manifold outlet within each time step. Calculations based on the aforementioned transient boundary conditions can obtain the initial boundary conditions of the flow field within that time step, i.e., the boundary position of the flow field, and the boundary conditions such as temperature and pressure of the flow field boundary. By mapping each time step to each set of transient boundary conditions, we can obtain the first three-dimensional model, the second three-dimensional model, the positional relationship, and the initial boundary conditions of the flow field for each time step. These parameters can be used as simulation parameters to perform transient simulation of the flow field.

[0050] As an optional embodiment, transient simulation of the flow field is performed based on the initial boundary conditions and the first simulation results of the flow field in the previous time step to obtain the flow field simulation data. This can include the following steps: determining the first volume grid corresponding to the flow field in the previous time step, wherein the first simulation results include the first volume grid, which is a volume grid used for simulating and calculating the flow field; adjusting the first volume grid according to the initial boundary conditions to obtain a second volume grid; and performing transient simulation of the flow field based on the second volume grid to obtain the flow field simulation data. Optionally, fluid simulation can be performed using the CFD fluid simulation software STARCCM+, in which fluid simulation can be performed by dividing the fluid into volume grids before calculation. During simulation, the fluid in the 3D model was simulated within the previous time step, yielding the fluid simulation results. The volume mesh generated from these results is designated as the first volume mesh. Before the start of the simulation at this new time step, the first and second 3D models and their positional relationships have changed between the previous and current time steps. The first volume mesh can be adjusted based on these changes, and the adjusted mesh is designated as the second volume mesh. Within this time step, calculations can be performed on the second volume mesh to obtain the fluid simulation results. The initial boundary conditions can be the model and its positional relationships. Optionally, the simulation for each time step can follow the above steps, starting with the first time step and continuing until the last time step. The resulting fluid simulation results serve as the simulation data for the flow field across multiple time steps.

[0051] As an optional embodiment, adjusting the first volume mesh according to the initial boundary conditions to obtain the second volume mesh may include the following steps: Given that the cylinder assembly includes a first component and the first component constitutes the outer surface of the flow field, determine the initial boundary conditions, including the shape and size of the first space formed by the first component and the exhaust manifold; based on the shape and size of the first space, stretch or compress the mesh corresponding to the first space in the first volume mesh to obtain the second volume mesh. Here, the first component can be a piston in the cylinder, and the shape and size of the first space formed by the first component and the exhaust manifold can be the shape and size of the space between the piston and the exhaust manifold within the cylinder, which is filled with the fluid participating in the simulation. Optionally, there are various methods for dividing the first volume mesh; in the simulation of piston motion, a deformable dynamic mesh can be used. Figure 4 This is a schematic diagram of a deformable dynamic mesh method for simulating piston motion according to an optional embodiment of the present invention. The deformable dynamic mesh generation method can be as follows: Figure 4As shown, the piston's motion can be represented by a deformed second-volume mesh. Based on the piston's position change in the initial boundary conditions, the piston's motion can be determined. Based on the piston's motion, the first-volume mesh can be adjusted to become a second-volume mesh, for example, as... Figure 4 (a) shows the flow field simulation results for the previous time step. When the initial boundary conditions show that the piston moves downward relative to the cylinder, the gas volume in the exhaust manifold expands, as shown in Figure (a). Figure 4 (b) shows that the first volume mesh can be stretched to obtain the second volume mesh.

[0052] As an optional embodiment, adjusting the first volume mesh according to the initial boundary conditions to obtain the second volume mesh may further include the following steps: When the cylinder assembly includes a second component and the second component is located inside the flow field, determine the initial boundary conditions, including the first position of the second component in the flow field. The first volume mesh includes the flow field mesh and the component mesh corresponding to the second component. The flow field mesh is a background domain mesh, and the component mesh is a superimposed domain mesh. Determine the second position of the component mesh within the flow field mesh. If the positional deviation between the first and second positions exceeds a deviation threshold, move the component mesh in the first volume mesh to the first position to obtain the second volume mesh. The second volume mesh includes the flow field mesh and the component mesh moved to the first position. The second component can be a valve. The background domain and superimposed domain are two different mesh attributes used to distinguish between two meshes participating in the simulation calculation according to different rules. Optionally, there are various methods for dividing the first volume mesh. In the simulation of valve motion, a superimposed moving mesh can be used for mesh division. Figure 5 This is a schematic diagram of a background domain volume mesh and an overlay domain volume mesh generation method provided by an optional embodiment of the present invention, as shown below. Figure 5 As shown, the computational mesh for the valve and the fluid around it can be divided into a background domain mesh and a superimposed domain mesh, such as... Figure 5 As shown in (a), the exhaust manifold and cylinder surrounding the valves constitute the background domain, and the computational mesh for fluid partitioning within it is the background domain volume mesh; as Figure 5 As shown in (b), the computational grid for the fluid around the valve is a superimposed domain volume grid. The outermost grid attribute of the superimposed domain volume grid is the internal interface. The physical values ​​of the grids on both sides of the internal interface can be obtained by interpolation, realizing data exchange between the background domain volume grid and the superimposed domain volume grid on both sides of the grid; Figure 5 (c) shows the grid pattern that divides the area around the valve. Optional, Figure 6 This is a schematic diagram of a superimposed dynamic mesh method for mimicking valve movement according to an optional embodiment of the present invention, as shown below. Figure 6 As shown in (a), the mesh near the valve is divided into a background domain mesh and a superimposed domain mesh, as follows: Figure 6As shown in (b), the calculation method for the superimposed dynamic mesh can be as follows: the background domain volume mesh is divided into activated meshes (meshes participating in the calculation) and inactive meshes (meshes not participating in the calculation), while the space within the background domain volume mesh is the space of inactive meshes, which is replaced by meshes within the superimposed domain for calculation. Optionally, the valve movement can be determined based on the valve position in the initial boundary conditions. After comparing the second position of the valve with the first position of the valve in the initial boundary conditions, if the deviation between the first and second positions exceeds a deviation threshold, it can be determined that the valve position will move from the second position to the first position. The first volume mesh can be adjusted to become the second volume mesh based on the movement of the valve position.

[0053] As an optional implementation, after obtaining the flow field simulation data, the data results can also be processed in the following way: Figure 7 This is a schematic diagram of a manifold cross-section division method provided by an optional embodiment of the present invention, as shown below. Figure 7 As shown in (a), the dashed line represents the centerline of the exhaust manifold. The centerlines of each manifold in the exhaust manifold can be normalized in length, such as... Figure 7 As shown in (b), a series of cross-sections perpendicular to the centerline can be constructed. Based on the transient simulation results of the fluid, the fluid simulation results for each cross-section can be obtained. By plotting the fluid simulation results for each cross-section, a visualized fluid simulation result diagram can be obtained. Finally, the fluid motion in the exhaust manifold can be obtained based on the cross-sectional parameter diagram. Specifically, Figure 8 This is a schematic diagram of the visualized fluid simulation results provided by an optional embodiment of the present invention, such as... Figure 8 As shown, when plotting the fluid simulation results, the crankshaft angle, i.e. the time step, can be used as the horizontal axis, and the section number of each manifold can be used as the vertical axis. The color represents the average mass flow rate on each manifold section, and finally a visualized fluid simulation result graph can be obtained.

[0054] As an optional embodiment of the present invention, the fluid simulation method can be implemented through the following steps: First, establish a three-dimensional model of the exhaust manifold, cylinder, and cylinder assembly to be simulated, and determine multiple time steps for transient simulation; then, import the three-dimensional model into one-dimensional thermodynamics software to calculate multiple sets of transient boundary conditions required for transient fluid simulation, wherein the multiple sets of transient boundary conditions include the positional relationship between the three-dimensional models and the flow field boundary conditions within each time step; second, import the three-dimensional model and the multiple sets of transient boundary conditions into the fluid simulation software, divide the three-dimensional model and the fluid therein into a computational mesh, and the obtained computational mesh is the first mesh. When performing fluid simulation calculations, first, based on the multiple sets of transient boundary conditions... The initial conditions are used to simulate the first grid within the first time step. After obtaining the fluid simulation results, the computational grid is adjusted according to the model position relationship of the second time step in multiple sets of transient boundary conditions. The resulting computational grid is the second grid. Based on the flow field boundary conditions corresponding to the multiple sets of transient boundary conditions in the second time step, the fluid simulation calculation is performed on the second grid within the second time step. After obtaining the fluid simulation results, the above steps are repeated to calculate the fluid simulation results for the next time step until the simulation calculation for the last time step is completed. At this point, the final fluid simulation result in the 3D model is obtained. Finally, the fluid simulation results can be plotted to achieve visualization of the fluid simulation results, which is convenient for technicians to analyze and judge the results.

[0055] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0056] Through the above description of the embodiments, those skilled in the art can clearly understand that the flow field simulation method according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platform. Of course, it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0057] Example 2

[0058] According to embodiments of the present invention, an apparatus for implementing the above-described flow field simulation method is also provided. Figure 9 This is a structural block diagram of the flow field simulation device provided according to an embodiment of the present invention, such as... Figure 9 As shown, the flow field simulation device includes: a first acquisition module 92, a second acquisition module 94, and a simulation module 96. The flow field simulation device will be described below.

[0059] The first acquisition module 92 is used to acquire a first three-dimensional model and a second three-dimensional model, wherein the first three-dimensional model includes a three-dimensional model of an exhaust manifold, and the second three-dimensional model includes a three-dimensional model of a cylinder assembly connected to the exhaust manifold.

[0060] The second acquisition module 94 is connected to the first acquisition module 92 and is used to acquire multiple sets of transient boundary conditions of the cylinder assembly at multiple consecutive moments.

[0061] The simulation module 96, connected to the second acquisition module 94, is used to perform transient simulation of the flow field corresponding to the exhaust manifold based on the first three-dimensional model, the second three-dimensional model, and the multiple sets of transient boundary conditions, and obtain the flow field simulation data of the flow field.

[0062] It should be noted that the first acquisition module 92, the second acquisition module 94, and the simulation module 96 mentioned above correspond to steps S202 to S206 in the embodiments. The three modules and their corresponding steps implement the same instances and application scenarios, but are not limited to the content disclosed in the above embodiments. It should also be noted that the above modules, as part of the device, can run in the computer terminal 10 provided in the embodiments.

[0063] Example 3

[0064] Embodiments of the present invention may provide a computer device. Optionally, in this embodiment, the computer device may be located in at least one of a plurality of network devices in a computer network. The computer device includes a memory and a processor.

[0065] The memory can be used to store software programs and modules, such as the program instructions / modules corresponding to the flow field simulation method and apparatus in this embodiment of the invention. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory, thereby realizing the aforementioned flow field simulation method. The memory may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory may further include memory remotely located relative to the processor, and these remote memories can be connected to a computer terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0066] The processor can call the information and application program stored in the memory through the transmission device to perform the following steps: acquiring a first three-dimensional model and a second three-dimensional model, wherein the first three-dimensional model includes a three-dimensional model of the exhaust manifold and the second three-dimensional model includes a three-dimensional model of the cylinder assembly connected to the exhaust manifold; acquiring multiple sets of transient boundary conditions of the cylinder assembly in multiple consecutive time steps; and performing transient simulation on the flow field corresponding to the exhaust manifold based on the first three-dimensional model, the second three-dimensional model and the multiple sets of transient boundary conditions to obtain flow field simulation data.

[0067] Optionally, the processor may also execute program code with the following steps: performing transient simulation on the flow field corresponding to the exhaust manifold based on the first three-dimensional model, the second three-dimensional model, and multiple sets of transient boundary conditions to obtain flow field simulation data, including: determining the positional relationship between the first three-dimensional model and the second three-dimensional model and the flow field boundary conditions in the time step corresponding to each set of transient boundary conditions based on the transient boundary conditions; determining the initial boundary conditions of the flow field in the current time step corresponding to any set of transient boundary conditions based on the first three-dimensional model, the second three-dimensional model, the positional relationship, and the flow field boundary conditions; and performing transient simulation on the flow field based on the initial boundary conditions and the first simulation result of the flow field in the previous time step of the current time step to obtain flow field simulation data.

[0068] Optionally, the processor may also execute program code with the following steps: performing transient simulation of the flow field based on the initial boundary conditions and the first simulation result of the flow field in the previous time step to obtain the flow field simulation data, including: determining the first volume grid corresponding to the flow field in the previous time step, wherein the first simulation result includes the first volume grid, which is a volume grid used for simulating and calculating the flow field; adjusting the first volume grid according to the initial boundary conditions to obtain the second volume grid; and performing transient simulation of the flow field based on the second volume grid to obtain the flow field simulation data.

[0069] Optionally, the processor may also execute program code for the following steps: adjusting the first body mesh according to the initial boundary conditions to obtain the second body mesh, including: when the cylinder assembly includes the first component and the first component constitutes the outer surface of the flow field, determining the shape and size of the first space formed by the first component and the exhaust manifold as the initial boundary conditions; stretching or compressing the mesh corresponding to the first space in the first body mesh according to the shape and size of the first space to obtain the second body mesh.

[0070] Optionally, the processor may also execute program code for the following steps: adjusting the first volume mesh according to the initial boundary conditions to obtain the second volume mesh, further including: when the cylinder assembly includes a second component and the second component is located inside the flow field, determining the initial boundary conditions including the first position of the second component in the flow field, the first volume mesh including the flow field volume mesh and the component volume mesh corresponding to the second component, the flow field volume mesh having the attribute of a background domain volume mesh, and the component volume mesh having the attribute of a superimposed domain volume mesh; determining the second position of the component volume mesh in the flow field volume mesh; when the positional deviation between the first position and the second position exceeds a deviation threshold, moving the component volume mesh in the first volume mesh to the first position to obtain the second volume mesh, wherein the second volume mesh includes the flow field volume mesh and the component volume mesh moved to the first position.

[0071] Optionally, the processor may also execute program code that performs the following steps: obtaining multiple sets of transient boundary conditions for the cylinder assembly at multiple consecutive moments, including: performing one-dimensional thermodynamic simulation on the cylinder assembly to obtain multiple sets of transient boundary conditions, wherein the multiple sets of transient boundary conditions include the position of the cylinder assembly, the flow field boundary pressure of the exhaust manifold, and the flow field boundary temperature.

[0072] Optionally, the processor may also execute program code that includes at least one of the following steps: the cylinder assembly includes a piston of the cylinder and a valve of the cylinder.

[0073] This invention provides a fluid simulation scheme. By acquiring a first three-dimensional model and a second three-dimensional model, wherein the first three-dimensional model includes a three-dimensional model of an exhaust manifold, and the second three-dimensional model includes a three-dimensional model of a cylinder assembly connected to the exhaust manifold; multiple sets of transient boundary conditions for the cylinder assembly in multiple consecutive time steps are acquired; based on the first three-dimensional model, the second three-dimensional model, and the multiple sets of transient boundary conditions, transient simulation of the flow field corresponding to the exhaust manifold is performed to obtain flow field simulation data. This achieves the goal of incorporating the motion of the piston and valves into the flow field simulation process, thereby improving the accuracy of the flow field simulation results and solving the technical problem in related technologies where the flow field in the exhaust manifold cannot be accurately simulated.

[0074] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing the hardware related to the terminal device. The program can be stored in a non-volatile storage medium, which may include: flash drive, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk, etc.

[0075] Example 4

[0076] Embodiments of the present invention also provide a non-volatile storage medium. Optionally, in this embodiment, the aforementioned non-volatile storage medium can be used to store the program code executed by the flow field simulation method provided in the above embodiments.

[0077] Optionally, in this embodiment, the non-volatile storage medium may be located in any computer terminal in a group of computer terminals in a computer network, or in any mobile terminal in a group of mobile terminals.

[0078] Optionally, in this embodiment, the non-volatile storage medium is configured to store program code for performing the following steps: acquiring a first three-dimensional model and a second three-dimensional model, wherein the first three-dimensional model includes a three-dimensional model of the exhaust manifold, and the second three-dimensional model includes a three-dimensional model of the cylinder assembly connected to the exhaust manifold; acquiring multiple sets of transient boundary conditions of the cylinder assembly in multiple consecutive time steps; and performing transient simulation on the flow field corresponding to the exhaust manifold based on the first three-dimensional model, the second three-dimensional model, and the multiple sets of transient boundary conditions to obtain flow field simulation data of the flow field.

[0079] Optionally, in this embodiment, the non-volatile storage medium is configured to store program code for performing the following steps: performing transient simulation on the flow field corresponding to the exhaust manifold based on the first three-dimensional model, the second three-dimensional model, and multiple sets of transient boundary conditions to obtain flow field simulation data, including: determining the positional relationship between the first three-dimensional model and the second three-dimensional model and the flow field boundary conditions in the time step corresponding to each set of transient boundary conditions based on the transient boundary conditions; determining the initial boundary conditions of the flow field in the current time step corresponding to any set of transient boundary conditions based on the first three-dimensional model, the second three-dimensional model, the positional relationship, and the flow field boundary conditions; performing transient simulation on the flow field based on the initial boundary conditions and the first simulation result of the flow field in the previous time step of the current time step to obtain flow field simulation data.

[0080] Optionally, in this embodiment, the non-volatile storage medium is configured to store program code for performing the following steps: performing transient simulation of the flow field based on the initial boundary conditions and the first simulation result of the flow field in the previous time step to obtain flow field simulation data, including: determining the first volume grid corresponding to the flow field in the previous time step, wherein the first simulation result includes the first volume grid, which is a volume grid used for simulating and calculating the flow field; adjusting the first volume grid according to the initial boundary conditions to obtain a second volume grid; and performing transient simulation of the flow field based on the second volume grid to obtain flow field simulation data.

[0081] Optionally, in this embodiment, the non-volatile storage medium is configured to store program code for performing the following steps: adjusting the first volume mesh according to the initial boundary conditions to obtain the second volume mesh, including: when the cylinder assembly includes the first component and the first component constitutes the outer surface of the flow field, determining the shape and size of the first space formed by the first component and the exhaust manifold as the initial boundary conditions; stretching or compressing the mesh corresponding to the first space in the first volume mesh according to the shape and size of the first space to obtain the second volume mesh.

[0082] Optionally, in this embodiment, the non-volatile storage medium is configured to store program code for performing the following steps: adjusting the first volume mesh according to initial boundary conditions to obtain a second volume mesh, further comprising: when the cylinder assembly includes a second component and the second component is located inside the flow field, determining the initial boundary conditions including the first position of the second component in the flow field, the first volume mesh including the flow field volume mesh and the component volume mesh corresponding to the second component, the flow field volume mesh having the attribute of a background domain volume mesh, and the component volume mesh having the attribute of an overlay domain volume mesh; determining the second position of the component volume mesh in the flow field volume mesh; when the positional deviation between the first position and the second position exceeds a deviation threshold, moving the component volume mesh in the first volume mesh to the first position to obtain the second volume mesh, wherein the second volume mesh includes the flow field volume mesh and the component volume mesh moved to the first position.

[0083] Optionally, in this embodiment, the non-volatile storage medium is configured to store program code for performing the following steps: obtaining multiple sets of transient boundary conditions of the cylinder assembly at multiple consecutive moments, including: performing one-dimensional thermodynamic simulation on the cylinder assembly to obtain multiple sets of transient boundary conditions, wherein the multiple sets of transient boundary conditions include the position of the cylinder assembly, the flow field boundary pressure of the exhaust manifold, and the flow field boundary temperature.

[0084] Optionally, in this embodiment, the non-volatile storage medium is configured to store program code for performing the following steps: the cylinder assembly includes at least one of the following: a piston of the cylinder, and a valve of the cylinder.

[0085] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0086] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0087] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0088] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0089] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0090] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a non-volatile storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0091] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A flow field simulation method, characterized in that, include: Obtain a first three-dimensional model and a second three-dimensional model, wherein the first three-dimensional model includes a three-dimensional model of an exhaust manifold, and the second three-dimensional model includes a three-dimensional model of a cylinder assembly connected to the exhaust manifold. Multiple sets of transient boundary conditions are obtained for the cylinder assembly in multiple consecutive time steps. The multiple sets of transient boundary conditions include the position of the cylinder assembly, the flow field boundary pressure and flow field boundary temperature of the exhaust manifold. Each set of transient boundary conditions is used to describe the state of the cylinder assembly within the time step corresponding to the transient boundary condition, and the influence of the state of the cylinder assembly within the time step on the boundary conditions of the flow field corresponding to the exhaust manifold. Based on the first three-dimensional model, the second three-dimensional model, and the multiple sets of transient boundary conditions, transient simulation is performed on the flow field corresponding to the exhaust manifold to obtain the flow field simulation data. The step of performing transient simulation on the flow field corresponding to the exhaust manifold based on the first three-dimensional model, the second three-dimensional model, and the multiple sets of transient boundary conditions to obtain the flow field simulation data includes: determining the positional relationship between the first three-dimensional model and the second three-dimensional model and the flow field boundary conditions of the flow field in the time step corresponding to each set of transient boundary conditions based on the transient boundary conditions; determining the initial boundary conditions of the flow field in the current time step corresponding to any set of transient boundary conditions based on the first three-dimensional model, the second three-dimensional model, the positional relationship, and the flow field boundary conditions; and performing transient simulation on the flow field based on the initial boundary conditions and the first simulation result of the flow field in the previous time step of the current time step to obtain the flow field simulation data.

2. The flow field simulation method according to claim 1, characterized in that, The transient simulation of the flow field is performed based on the initial boundary conditions and the first simulation result of the flow field in the previous time step to obtain the flow field simulation data, including: The first volume grid corresponding to the flow field in the previous time step is determined, wherein the first simulation result includes the first volume grid, which is a volume grid used for simulating and calculating the flow field; The first volume mesh is adjusted according to the initial boundary conditions to obtain the second volume mesh; The flow field is transiently simulated based on the second body mesh to obtain the flow field simulation data.

3. The flow field simulation method according to claim 2, characterized in that, The step of adjusting the first volume mesh according to the initial boundary conditions to obtain the second volume mesh includes: When the cylinder assembly includes a first component and the first component constitutes the outer surface of the flow field, the initial boundary conditions are determined to include the shape and size of the first space formed by the first component and the exhaust manifold. Based on the shape and size of the first space, stretch or compress the mesh corresponding to the first space in the first volume mesh to obtain the second volume mesh.

4. The flow field simulation method according to claim 2, characterized in that, The step of adjusting the first volume mesh according to the initial boundary conditions to obtain the second volume mesh further includes: When the cylinder assembly includes a second component and the second component is located inside the flow field, the initial boundary conditions are determined to include the first position of the second component in the flow field. The first volume mesh includes a flow field volume mesh and a component volume mesh corresponding to the second component. The flow field volume mesh is a background domain volume mesh, and the component volume mesh is an overlay domain volume mesh. Determine the second position of the component volume mesh within the flow field volume mesh; If the positional deviation between the first position and the second position exceeds a deviation threshold, the component volume mesh in the first volume mesh is moved to the first position to obtain the second volume mesh, wherein the second volume mesh includes the flow field volume mesh and the component volume mesh moved to the first position.

5. The flow field simulation method according to claim 1, characterized in that, Obtaining multiple sets of transient boundary conditions for the cylinder assembly at multiple consecutive moments includes: performing one-dimensional thermodynamic simulation on the cylinder assembly to obtain the multiple sets of transient boundary conditions.

6. The flow field simulation method according to any one of claims 1 to 5, characterized in that, The cylinder assembly includes at least one of the following: a piston of the cylinder, and a valve of the cylinder.

7. A flow field simulation device, characterized in that, include: The first acquisition module is used to acquire a first three-dimensional model and a second three-dimensional model, wherein the first three-dimensional model includes a three-dimensional model of an exhaust manifold, and the second three-dimensional model includes a three-dimensional model of a cylinder assembly connected to the exhaust manifold. The second acquisition module is used to acquire multiple sets of transient boundary conditions of the cylinder assembly in multiple consecutive time steps. The multiple sets of transient boundary conditions include the position of the cylinder assembly, the flow field boundary pressure and flow field boundary temperature of the exhaust manifold. Each set of transient boundary conditions is used to describe the state of the cylinder assembly within the time step corresponding to the transient boundary condition, and the influence of the state of the cylinder assembly within the time step on the boundary conditions of the flow field corresponding to the exhaust manifold. The simulation module is used to perform transient simulation of the flow field corresponding to the exhaust manifold based on the first three-dimensional model, the second three-dimensional model, and the multiple sets of transient boundary conditions, so as to obtain the flow field simulation data of the flow field. The simulation module is further configured to perform transient simulation of the flow field corresponding to the exhaust manifold based on the first three-dimensional model, the second three-dimensional model, and the multiple sets of transient boundary conditions through the following steps to obtain the flow field simulation data: Based on the transient boundary conditions, determine the positional relationship between the first three-dimensional model and the second three-dimensional model and the flow field boundary conditions of the flow field in the time step corresponding to each set of transient boundary conditions; based on the first three-dimensional model, the second three-dimensional model, the positional relationship, and the flow field boundary conditions, determine the initial boundary conditions of the flow field in the current time step corresponding to any set of transient boundary conditions; based on the initial boundary conditions and the first simulation result of the flow field in the previous time step of the current time step, perform transient simulation of the flow field to obtain the flow field simulation data.

8. A non-volatile storage medium, characterized in that, The non-volatile storage medium includes a stored program, wherein, when the program is executed, it controls the device containing the non-volatile storage medium to perform the flow field simulation method according to any one of claims 1 to 6.

9. A computer device, characterized in that, The computer device includes a processor for running a program, wherein the program executes the flow field simulation method according to any one of claims 1 to 6.

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