Full-cycle simulation method for interference unsteady flow of moving and static blades of fan / gas compressor

Abstract

The invention provides a full-cycle simulation method for disturbance unsteady flow of moving and static blades of a fan / gas compressor, which comprises the following steps of: acquiring three-dimensional geometry of a two-stage fan from the outside, generating a full-cycle grid through the three-dimensional geometry, and appointing boundary conditions, converting the generated grid file and the boundary condition file into an input file format required by a flow solving process; an unsteady Reynolds average equation is solved through a double-time-step method on the basis of the full-cycle grid and the boundary condition after format conversion, and a rotor-stator interface is processed through a sliding grid method in the sub-iteration solving process; and after solving is completed, outputting aerodynamic performance parameters of the fan in a text format and outputting a three-dimensional transient flow data file in a binary format. According to the method, the flow control equation is solved in different reference systems, the rotor and the stator are connected through the slip grid on the rotor-stator interface, accurate unsteady flow simulation is achieved, and therefore aerodynamic performance parameters of the fan / compressor are accurately predicted, and three-dimensional transient flow details are revealed.

Description

Technical Field

[0001] This application relates to the field of aviation technology, and particularly to a full - circumference simulation method for unsteady flow of fan / compressor stator - rotor blade interference. Background Art

[0002] Fans and compressors are key components of aero - engines. Accurately predicting their aerodynamic performance is of great significance for engine design, and numerical flow simulation is a powerful means for predicting aerodynamic performance. The functions of fans and compressors are both to compress air, and their flow simulation methods are basically the same. Currently, the most popular fan / compressor flow simulation software is Fine / Turbo of NUMECA Company in Belgium and CFX of ANSYS Company in the United States. The mainstream simulation method is single - channel steady - state RANS calculation, and the mixing - plane method is used at the rotor - stator interface. This method only simulates a single blade for each blade row. At the interface of adjacent blade rows, the flow variables are first circumferentially averaged, and then data is exchanged with each other. The above - mentioned method has a small computational amount and can obtain the aerodynamic performance of the fan / compressor relatively quickly.

[0003] The defect of the prior art is that it ignores the details of unsteady flow. Especially, the introduction of the mixing - plane approximation at the rotor - stator interface ignores the unsteady interference between the stator and rotor blades, including important flow structures such as blade wakes and shock waves. This cannot meet the accurate simulation requirements of designers for aerodynamic performance and blade loads. In modern fans / compressors, the axial distance between the rotor and stator is small, and the stator - rotor blade interference effect is strong. Moreover, the number of blades in different stages is relatively prime, and it is difficult to simplify the computational domain based on periodicity. Summary of the Invention

[0004] This application aims to solve at least one of the technical problems in the related art to some extent.

[0005] To this end, the first object of this application is to propose a full - circumference simulation method for unsteady flow of fan / compressor stator - rotor blade interference.

[0006] The second object of this application is to propose an apparatus for the full - circumference simulation method for unsteady flow of fan / compressor stator - rotor blade interference.

[0007] The third object of this application is to propose an electronic device.

[0008] The fourth object of this application is to propose a computer - readable storage medium.

[0009] The fifth object of this application is to propose a computer program product.

[0010] To achieve the above object, the first - aspect embodiment of this application proposes a full - circumference simulation method for unsteady flow of fan / compressor stator - rotor blade interference, including:

[0011] Obtain the three-dimensional geometry of the two-stage fan from the outside, generate a full-circumference grid through the three-dimensional geometry and specify boundary conditions, and convert the generated grid file and boundary condition file into the input file format required for the flow solution process;

[0012] Based on the full-circumference grid and boundary conditions after format conversion, solve the unsteady Reynolds-averaged equations by the dual-time stepping method. Among them, the dual-time stepping method divides the solution process into two layers of iteration. The main iteration refers to the advancement of the physical time step, and the sub-iteration refers to the advancement of the pseudo-time step. During the sub-iteration solution process, the sliding mesh method is used to handle the stator-rotor interface;

[0013] After the solution is completed, output the aerodynamic performance parameters of the fan in text format and output the three-dimensional transient flow data file in binary format.

[0014] Optionally, the solving of the unsteady Reynolds-averaged equations by the dual-time stepping method based on the converted full-circumference grid and boundary conditions includes:

[0015] Initialize the flow field based on the full-circumference grid and boundary conditions after format conversion;

[0016] Perform the pseudo-time step advancement through the sub-iteration process of solving the unsteady Reynolds-averaged equations;

[0017] Judge whether the sub-iteration converges. If the sub-iteration converges, perform the main time step advancement and output the aerodynamic performance parameters of the transient flow field;

[0018] Judge whether the main iteration is completed. If it is completed, end the calculation and generate the final aerodynamic performance parameters and transient flow field data file.

[0019] Optionally, the judging whether the sub-iteration converges includes:

[0020] After each sub-iteration ends, judge whether the change amount of the flow field is less than a predetermined convergence criterion;

[0021] If it is judged that the change amount of the flow field is less than the predetermined convergence criterion, judge that the sub-iteration converges, otherwise judge that the sub-iteration does not converge.

[0022] Optionally, it further includes:

[0023] If the sub-iteration does not converge, re-perform the sub-iteration solution process until the convergence condition is satisfied.

[0024] If the main iteration is not completed, re-perform the sub-iteration solution process until the convergence condition is satisfied.

[0025] Optionally, the performing the pseudo-time step advancement through the sub-iteration process of solving the unsteady Reynolds-averaged equations includes:

[0026] Discretize the boundary conditions of the flow field, convert the boundary conditions into a discrete format suitable for numerical calculation, and correctly apply them to the calculation of the flow field;

[0027] Process the rotor-stator interface by the sliding mesh method, and calculate the rotor and stator flows in the rotating and stationary reference frames respectively,

[0028] In a parallel computing environment, establish a local communication domain at each rotor-stator interface; within the local communication domain, each process packs all data into a one-dimensional array and performs inter-core data communication through the parallel broadcast mechanism;

[0029] Discretize the viscous terms using the second-order central difference scheme to ensure that the viscous effects in the flow field can be accurately calculated;

[0030] Discretize the inviscid terms using the third-order MUSCL reconstruction scheme combined with the rotational Roe scheme to ensure high-precision calculation and improve numerical stability;

[0031] Discretize the source terms to ensure that the influence of the source terms on the flow field during the calculation is accurately incorporated;

[0032] In each sub-iteration, gradually optimize the flow field calculation by advancing the pseudo-time step.

[0033] Optionally, the process of processing the rotor-stator interface by the sliding mesh method and calculating the rotor and stator flows in the rotating and stationary reference frames respectively includes:

[0034] When processing the rotor-stator interface, the grid on the rotor side rotates according to the physical angular velocity and time, and exchanges the flow information of adjacent grids on both sides of the rotor-stator interface according to its instantaneous position;

[0035] Among them, it is designed that the radial grid point distributions on both sides of the rotor-stator interface are the same, but the circumferential grid points are not restricted; only one-dimensional search is performed in the circumferential direction to determine the adjacent grid relationship, and linear interpolation and reference frame conversion are performed to complete the information exchange between the rotor and stator sides.

[0036] To achieve the above object, the second aspect embodiment of the present application proposes a full-circumference simulation device for unsteady flow of fan / compressor rotor-stator interference, which is characterized in that it includes:

[0037] A preprocessing module for obtaining the three-dimensional geometry of a two-stage fan from the outside, generating a full-circumference grid and specifying boundary conditions through the three-dimensional geometry, and converting the generated grid file and boundary condition file into the input file format required for the flow solution process;

[0038] A flow solution module, which is used to solve the unsteady Reynolds-averaged equations based on the full-annulus grid and boundary conditions after format conversion by using a dual-time-step method. In the dual-time-step method, the solution process is divided into two-layer iterations. The main iteration refers to the advancement of the physical time step, and the sub-iteration refers to the advancement of the pseudo-time step. During the sub-iteration solution process, the sliding mesh method is used to handle the stator-rotor interface.

[0039] A post-processing module, which is used to output the aerodynamic performance parameters of the fan in text format and output a three-dimensional transient flow data file in binary format after the solution is completed.

[0040] To achieve the above object, an embodiment of the third aspect of the present application proposes an electronic device, including: a processor, and a memory communicatively connected to the processor;

[0041] The memory stores computer-executable instructions;

[0042] The processor executes the computer-executable instructions stored in the memory to implement the method described in any one of the above first aspects.

[0043] To achieve the above object, an embodiment of the fourth aspect of the present application proposes a computer-readable storage medium, in which computer-executable instructions are stored, and when the computer-executable instructions are executed by a processor, they are used to implement the method described in any one of the above first aspects.

[0044] To achieve the above object, an embodiment of the fifth aspect of the present application proposes a computer program product, including a computer program, and when the computer program is executed by a processor, it implements the method described in any one of the above first aspects.

[0045] The technical solutions provided by the embodiments of the present application at least bring the following beneficial effects:

[0046] At the technical level, compared with the mainstream single-channel steady RANS method, the present application can significantly improve the calculation accuracy. The present application can capture important stator-rotor interference flow phenomena such as blade wakes and shocks, and accurately simulate the aerodynamic performance and blade loads of fans / compressors.

[0047] At the application level, the present application is used for high-fidelity fan / compressor flow simulation, mainly for the detailed design stage. The present application can accurately predict the unsteady flow details inside the fan / compressor according to the needs of designers, and is especially suitable for studying the stator-rotor interference mechanism, providing a data basis for the detailed optimization of aeroengines.

[0048] The additional aspects and advantages of the present application will be partly given in the following description, partly will become obvious from the following description, or will be understood through the practice of the present application. Description of the Drawings

[0049] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description of embodiments in conjunction with the accompanying drawings, where:

[0050] Figure 1 is a schematic diagram of a simple process for a full - circumference simulation method of unsteady flow caused by the interaction between the stator and rotor blades of a fan / compressor provided by an embodiment of the present application;

[0051] Figure 2 is a schematic diagram of a complete process for a full - circumference simulation method of unsteady flow caused by the interaction between the stator and rotor blades of a fan / compressor provided by an embodiment of the present application;

[0052] Figure 3 is a schematic diagram of the stator - rotor interface provided by an embodiment of the present application;

[0053] Figure 4 is a schematic diagram of the structure of a full - circumference simulation device for unsteady flow caused by the interaction between the stator and rotor blades of a fan / compressor provided by an embodiment of the present application. Detailed Embodiments

[0054] The embodiments of the present application will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application, and should not be construed as limiting the present application.

[0055] There are two key points in the full - circumference simulation of unsteady flow caused by the interaction between the stator and rotor blades of a fan / compressor: one is an excellent control - equation solving model, and the other is accurate treatment of the stator - rotor interface. It is necessary to balance computational accuracy, cost, and stability. At present, most full - circumference simulation studies still have deficiencies in this regard. The present application designs an accurate and stable full - circumference simulation method according to the flow characteristics of the fan / compressor. Figure 1 and Figure 2 is a schematic diagram of the process of a full - circumference simulation method of unsteady flow caused by the interaction between the stator and rotor blades of a fan / compressor provided by an embodiment of the present application. As Figure 1 shown, the method includes the following steps:

[0056] Step 101, obtain the three - dimensional geometry of a two - stage fan from the outside, generate a full - circumference grid and specify boundary conditions through the three - dimensional geometry, and convert the generated grid file and boundary - condition file into the input - file format required for the flow - solving process.

[0057] In the embodiments of the present application, first, the three-dimensional geometric data of the two-stage fan needs to be obtained. This three-dimensional geometric data usually comes from the fan design stage and is generated by CAD (Computer-Aided Design) tools or exported from existing design databases. The obtained three-dimensional geometric data is the complete geometric shape of the fan, including the detailed design parameters of the rotor and stator. This geometric data usually contains key information such as the size, shape, angle, and material properties of the fan blades, and is the basis for performing flow solutions.

[0058] As a possible implementation, in the embodiments of the present application, the full-annulus grid of the fan is generated by the commercial software NUMECA AutoGrid5. AutoGrid5 is a grid generation tool widely used in aerodynamic simulations and can automatically generate the grid of the fluid domain according to the input geometric information. To ensure the accuracy of the calculation results, AutoGrid5 will mesh the fluid domain according to the provided three-dimensional geometric data according to specific division rules, including the size, structure, and type of the grid (such as structured grid or unstructured grid), and allocate the grid to the rotor and stator regions of the fan. At the same time, AutoGrid5 will also specify appropriate boundary conditions (such as inlet and outlet boundaries, wall boundaries, etc.) for the grid as needed.

[0059] Subsequently, the generated grid file and boundary condition file will be converted through a program independently developed by the present application. The main function of this program is to convert the grid file format and boundary condition file format generated by AutoGrid5 into an input format suitable for this flow solution program. This conversion program ensures seamless docking between different software platforms and guarantees the accuracy and consistency of the input data during the subsequent calculation process. After the conversion is completed, the obtained file will be used for the subsequent flow solution process.

[0060] This preprocessing step ensures the orderly connection of each link from geometric acquisition to grid generation, boundary condition setting, and file conversion, prepares an accurate calculation model, and provides the necessary data support for subsequent flow simulation and solution.

[0061] Step 102, based on the format-converted full-annulus grid and boundary conditions, solve the unsteady Reynolds-averaged equations by the dual-time stepping method. In the dual-time stepping method, the solution process is divided into two-layer iterations. The main iteration refers to the advancement of the physical time step, and the sub-iteration refers to the advancement of the pseudo-time step. During the sub-iteration solution process, the sliding mesh method is used to handle the rotor-stator interface.

[0062] In the embodiments of the present application, based on the full - circumference grid and boundary conditions after format conversion obtained in the foregoing step 101, a self - written program is used for flow solution. The flow solution adopts the framework of the unsteady Reynolds - averaged Navier - Stokes equations (URANS). Under the URANS framework, the classical SST k - ω turbulence model is adopted to simulate the unsteady flow of the fan / compressor. This model is widely used in the field of flow simulation such as fans / compressors and can accurately describe complex turbulent characteristics.

[0063] To improve the computational efficiency and stability, the present invention adopts the dual - time - step method, which divides the solution process into two main iterative levels: the main iteration and the sub - iteration. The main iteration corresponds to the advancement of the physical time step. After each main iteration is completed, a transient flow field at a certain moment is obtained; while the sub - iteration corresponds to the advancement of the pseudo - time step. During the sub - iteration process, the steady - state solution of the flow field is gradually approximated.

[0064] This step specifically includes the following processes:

[0065] (1) Flow - field initialization process.

[0066] In the embodiments of the present application, the flow - field initialization is performed through the full - circumference grid and boundary conditions after format conversion. The initialization process includes assigning appropriate initial values to each grid point, and these initial values can be set according to physical boundary conditions or empirical values. The initialized flow field provides an initial state for subsequent calculations.

[0067] (2) Sub - iteration process.

[0068] In the embodiments of the present application, the sub - iteration process is a crucial part in the dual - time - step method, which continuously optimizes the flow - field solution through the advancement of the pseudo - time step. The specific sub - iteration steps include:

[0069] Step 201, at the beginning of each sub - iteration, first discretize the boundary conditions to ensure that the flow characteristics of the boundary can be accurately converted into numerical form and correctly applied to the calculation of the entire flow field.

[0070] Step 202, adopt the sliding - mesh method to handle the rotor - stator interface.

[0071] In the embodiments of the present application, the sliding - mesh method is adopted to handle the rotor - stator interface. The basic processing idea is that the rotor and stator flows are calculated in the rotating reference frame and the stationary reference frame respectively to handle the flow interface between them. Specifically, when dealing with the rotor - stator interface, the grids on the rotor side rotate according to the physical angular velocity and time, and then according to their instantaneous positions, the flow information of adjacent grids on both sides of the rotor - stator interface is exchanged.

[0072] At the rotor-stator interface, the grids on the rotor side and the stator side often do not match exactly in the circumferential direction. To solve this problem, this application stipulates that the distribution of radial grid points on both sides of the rotor-stator interface must be the same, while the distribution of circumferential grid points can be mismatched. This requirement is particularly applicable to applications such as fans / compressors and can be relatively easily implemented in numerical calculations. The advantage of this method is that it simplifies the complexity of data exchange and avoids the requirement for overly precise grid matching, thereby reducing the computational complexity. Therefore, for each layer of radial grids, only data exchange within a two-dimensional plane needs to be considered, as Figure 3 shown.

[0073] Referring to Figure 3 , in the figure, θ represents the circumferential coordinate, Q represents all flow variables, including conserved variables, vectors, and second-order tensors, the subscript i represents the grid to be interpolated, and the subscripts 1 and 2 represent the data source grids on the opposite side respectively. Since the grids only mismatch in the circumferential direction, when performing rotor-stator interface data exchange, the program only needs to perform a one-dimensional search in the circumferential direction to determine the adjacent relationship between the grids on the rotor side and the stator side. Specifically, through the one-dimensional search, the program can determine the adjacent grids on each layer of radial grids and use linear interpolation to exchange the flow information between the two-sided grids. The reason for choosing linear interpolation here is that it has simple calculations, few interpolation points, good stability, and sufficient computational accuracy.

[0074] After exchanging the flow information, the program will also perform a reference frame conversion to convert the flow information on the rotor side to the stator side reference frame, and vice versa. This process ensures that the flow field data can be accurately matched between different reference frames and avoids errors or discontinuities caused by reference frame conversion.

[0075] The method of this application for handling the rotor-stator interface can effectively maintain the continuity of the flow field. In the embodiments of this application, for the three rotor-stator interfaces of a two-stage fan, the relative error of the mass flow rate on both sides of each interface is less than 0.02%, the relative error of the total pressure is less than 0.05%, the relative error of the static pressure is less than 0.11%, and the relative error of the total temperature is less than 0.01%. There is a shock discontinuity at the interface between the first-stage stator and the second-stage rotor, and the relative error is still less than the above values.

[0076] To improve the computational efficiency, the embodiments of this application set the physical time step to an integer fraction of the rotor rotation period. In this way, initially, the program can calculate the grid positions for all time steps. By this means, the program can calculate the grid data exchange information for all time steps at once, thereby avoiding the need to re-search the grid positions within each time step. This greatly improves the computational efficiency, reduces repeated calculations and unnecessary data exchange, and improves the overall computational performance.

[0077] Generally speaking, the core advantage of using the sliding mesh method to handle the rotor-stator interface lies in its ability to efficiently solve the relative motion between the rotor and the stator while maintaining the accurate transfer of flow data. Through reasonable mesh design, interpolation methods, and reference frame transformation, this method can ensure the continuity and physical rationality of the flow field at the rotor-stator interface, thereby improving the accuracy and efficiency of the entire simulation process.

[0078] Step 203, the full-annulus unsteady flow simulation of the fan / compressor usually involves parallel computing. Each core is only responsible for a part of the flow field, but adjacent flow field information is required, so data communication between cores is needed, especially at the rotor-stator interface where the communication volume is relatively large. Considering that there are usually multiple rotor-stator interfaces in the fan / compressor, the present application establishes a local communication domain at each rotor-stator interface. Within the local communication domain, each process first packs all data into a one-dimensional array and then uses the parallel broadcast method for data communication. In addition, the full-annulus numerical simulation involves many grid blocks, and the present application also designs a grouped communication strategy for the point-to-point overlapping blocks. The above strategies can effectively improve the communication speed.

[0079] Step 204, during the sub-iteration process, the present application uses the second-order central difference scheme to discretize the viscous terms. This discretization method can accurately reflect the viscous effects in the flow field and ensure the accuracy of the calculation.

[0080] Step 205, similarly, the present application combines the third-order MUSCL reconstruction scheme with the rotational Roe scheme to discretize the inviscid terms. The rotational Roe scheme has better computational stability compared to the standard Roe scheme. This set of numerical discretization schemes can obtain good accuracy in combination with URANS, and has better stability than the mainstream schemes, especially in complex flow scenarios such as high-speed flows or vortices.

[0081] Step 206, during the numerical solution process, the discretization of source terms (such as external forces, heat sources, etc.) is crucial. The embodiments of the present application ensure that the influence of the source terms on the flow field can be correctly incorporated into the calculation through accurate discretization methods, thereby avoiding the accumulation of calculation errors and ensuring the accuracy of the final result.

[0082] Step 207, in each sub-iteration, the present application gradually approaches the steady-state solution of the flow field through the pseudo-time step advancement method. In each pseudo-time step, the physical quantities of the flow field are gradually adjusted until the convergence condition is met. The pseudo-time step advancement can effectively accelerate the convergence process and ensure the accuracy and stability of the final solution.

[0083] (3) Sub-iteration convergence judgment process.

[0084] At the end of each sub-iteration, the embodiment of the present application determines whether the sub-iteration converges by judging whether the change amount of the flow field is less than a predetermined convergence criterion. If the change amount of the flow field in the sub-iteration is less than the set criterion, it is considered that the sub-iteration has converged, and the program will enter the main time step advancement. If not converged, the sub-iteration solution will continue until the convergence condition is met.

[0085] (4) Main iteration process.

[0086] Once the sub-iteration converges, it enters the main time step advancement process. The main time step advancement evolves the flow field through the physical time step and updates the flow state at each time step. After the main time step advancement is completed, the transient flow field at the current time point is calculated, and the aerodynamic performance parameters of the fan, such as efficiency, pressure ratio, etc., are output.

[0087] After each main iteration is completed, the program will judge whether the main iteration has been completed. If the main iteration has been completed, the entire calculation process ends, and the program generates the final aerodynamic performance parameters and transient flow field data files; if the main iteration is not completed, it enters the next main iteration step and re-performs the sub-iteration solution process within the new main iteration step until the convergence condition is met.

[0088] Step 103, after the solution is completed, output the aerodynamic performance parameters of the fan in text format and output the three-dimensional transient flow data file in binary format.

[0089] After all the calculations of the flow solution program are completed, the post-processing step of the present invention will automatically generate the aerodynamic performance parameters of the fan and output them in text format. Specifically, the output aerodynamic performance parameters include but are not limited to key parameters such as pressure ratio, efficiency, etc., which are the core indicators for evaluating the performance of the fan or compressor. Through these aerodynamic performance parameters, users can quickly understand the performance of the fan under different operating conditions and provide data support for subsequent design optimization.

[0090] In addition, in addition to the text output of the aerodynamic performance parameters, the program will also automatically generate and output three-dimensional transient flow data files. These data files are stored in binary format to ensure efficient reading, writing, and storage when dealing with large amounts of data. The output three-dimensional transient flow data files contain detailed flow information at each time step, covering various variables in the flow field (such as pressure, temperature, velocity components, etc.). These data files can be opened and analyzed by commercial software such as tecplot 360, and users can use these visualization tools to conduct in-depth analysis of the flow details and further study the characteristics and behaviors of the flow.

[0091] During the entire post - processing process, the program not only ensures the accuracy of the calculation results but also guarantees that the data formatting and storage methods comply with industry standards, facilitating users to view data and conduct subsequent analysis on different platforms. Through automated post - processing steps, users can quickly obtain the required performance metrics and detailed flow data after the calculation is completed, greatly improving work efficiency and data availability.

[0092] To implement the above - mentioned embodiments, the present application also proposes a full - circumference simulation device for unsteady flow of the interference between the stator and rotor blades of a fan / compressor. Figure 4 It is a schematic structural diagram of a full - circumference simulation device 10 for unsteady flow of the interference between the stator and rotor blades of a fan / compressor provided by an embodiment of the present application. As Figure 4 shown, the device includes:

[0093] A pre - processing module 100, configured to obtain the three - dimensional geometry of a two - stage fan from the outside, generate a full - circumference grid through the three - dimensional geometry and specify boundary conditions, and convert the generated grid file and boundary condition file into the input file format required for the flow solution process;

[0094] A flow solution module 200, configured to solve the unsteady Reynolds - averaged equations based on the full - circumference grid and boundary conditions after format conversion. Among them, the dual - time - step method divides the solution process into two - layer iterations. The main iteration refers to the advancement of the physical time step, and the sub - iteration refers to the advancement of the pseudo - time step. During the sub - iteration solution process, the sliding - mesh method is used to handle the stator - rotor interface;

[0095] A post - processing module 300, configured to output the aerodynamic performance parameters of the fan in text format and output a three - dimensional transient flow data file in binary format after the solution is completed.

[0096] Regarding the device in the above - mentioned embodiments, the specific ways in which each module performs operations have been described in detail in the embodiments related to the method, and will not be elaborated here.

[0097] To implement the above - mentioned embodiments, the present application also proposes an electronic device, including: a processor, and a memory communicatively connected to the processor; the memory stores computer - executable instructions; the processor executes the computer - executable instructions stored in the memory to implement the method provided in the foregoing embodiments.

[0098] To implement the above - mentioned embodiments, the present application also proposes a computer - readable storage medium storing computer - executable instructions, and when the computer - executable instructions are executed by a processor, they are used to implement the method provided in the foregoing embodiments.

[0099] To implement the above embodiments, the present application also provides a computer program product, including a computer program which, when executed by a processor, implements the methods provided in the foregoing embodiments.

[0100] The collection, storage, use, processing, transmission, provision, and disclosure of the user's personal information involved in this application all comply with the provisions of relevant laws and regulations and do not violate public order and good customs.

[0101] It should be noted that personal information from users should be collected for legal and reasonable purposes and should not be shared or sold outside of these legitimate uses. In addition, such collection / sharing should be carried out after obtaining the informed consent of the user, including but not limited to notifying the user to read the user agreement / user notice and sign an agreement / authorization including authorizing relevant user information before the user uses the function. In addition, any necessary steps should be taken to protect and safeguard access to such personal information data and ensure that others with access to personal information data comply with their privacy policies and procedures.

[0102] This application anticipates providing embodiments where users can selectively block the use or access of personal information data. That is, this disclosure anticipates providing hardware and / or software to prevent or block access to such personal information data. Once personal information data is no longer needed, the risk can be minimized by restricting data collection and deleting the data. In addition, when applicable, personal identifiers are removed from such personal information to protect the privacy of the user.

[0103] In the description of the foregoing embodiments, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0104] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" can explicitly or implicitly include at least one of the features. In the description of this application, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0105] Any process or method description represented in a flowchart or otherwise described herein can be understood to represent a module, segment, or portion of code including one or more executable instructions for implementing a customized logical function or process, and the scope of the preferred embodiments of the present application includes additional implementations, where functions may be performed in a substantially simultaneous manner or in a reverse order according to the functions involved, rather than in the order shown or discussed, which should be understood by those skilled in the art to which the embodiments of the present application pertain.

[0106] Logic and / or steps represented in a flowchart or otherwise described herein, for example, can be considered a sequenced list of executable instructions for implementing a logical function, and can be embodied specifically in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection having one or more wires (electronic device), a portable computer diskette (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or other suitable medium on which the program can be printed, as the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpretation, or other suitable processing as necessary, and then stored in a computer memory.

[0107] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one or a combination of the following techniques known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), etc.

[0108] Those of ordinary skill in the art can understand that all or part of the steps carried out in implementing the above method embodiments can be completed by instructing relevant hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiments.

[0109] In addition, in each of the embodiments of the present application, the functional units can be integrated into one processing module, or each unit can exist physically alone, or two or more units can be integrated into one module. The above integrated module can be implemented in the form of hardware or in the form of a software functional module. When the above integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0110] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disc, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present application.

[0111] It should be understood that various forms of the processes shown above can be used, steps can be reordered, added or deleted. For example, the steps described in the present application can be executed in parallel, sequentially or in a different order, as long as the desired results of the technical solution of the present application can be achieved, and no limitation is imposed herein.

[0112] The above specific embodiments do not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A full - circumference simulation method for unsteady flow of fan / compressor stator - rotor blade interference, characterized in that It includes the following steps: Obtain the three-dimensional geometry of a two-stage fan from the outside, generate a full-annulus mesh through the three-dimensional geometry and specify boundary conditions, and convert the generated mesh file and boundary condition file into the input file format required for the flow solution process; Based on the full-annulus mesh and boundary conditions after format conversion, solve the unsteady Reynolds-averaged equations by the dual-time stepping method. Among them, the dual-time stepping method divides the solution process into two-layer iterations. The main iteration refers to the advancement of the physical time step, and the sub-iteration refers to the advancement of the pseudo-time step. During the sub-iteration solution process, the sliding mesh method is used to handle the rotor-stator interface; After the solution is completed, output the aerodynamic performance parameters of the fan in text format and output the three-dimensional transient flow data file in binary format.

2. The method according to claim 1, wherein The solving of the unsteady Reynolds-averaged equations by the dual-time stepping method based on the converted full-annulus mesh and boundary conditions includes: Initialize the flow field based on the full-annulus mesh and boundary conditions after format conversion; Solve the sub-iteration process through the unsteady Reynolds-averaged equations and perform pseudo-time step advancement; Judge whether the sub-iteration converges. If the sub-iteration converges, perform the main time step advancement and output the aerodynamic performance parameters of the transient flow field; Judge whether the main iteration is completed. If it is completed, end the calculation and generate the final aerodynamic performance parameters and transient flow field data file.

3. The method according to claim 2, characterized in that The judging whether the sub-iteration converges includes: After each sub-iteration ends, judge whether the change amount of the flow field is less than a predetermined convergence criterion; If it is judged that the change amount of the flow field is less than the predetermined convergence criterion, judge that the sub-iteration converges, otherwise judge that the sub-iteration does not converge.

4. The method according to claim 3, wherein It also includes: If the sub-iteration does not converge, re-perform the sub-iteration solution process until the convergence condition is satisfied. If the main iteration is not completed, re-perform the sub-iteration solution process until the convergence condition is satisfied.

5. The method according to claim 4, wherein The solving of the sub-iteration process through the unsteady Reynolds-averaged equations and performing pseudo-time step advancement includes: Discretize the boundary conditions of the flow field, convert the boundary conditions into a discrete format suitable for numerical calculation, and correctly apply them to the calculation of the flow field; Handle the rotor-stator interface by the sliding mesh method, and calculate the rotor and stator flows in the rotating and stationary reference frames respectively; In a parallel computing environment, establish a local communication domain at each rotor-stator interface; within the local communication domain, each process packs all data into a one-dimensional array and performs inter-core data communication through the parallel broadcast mechanism; Discretize the viscous terms using the second-order central difference format to ensure that the viscous effects in the flow field can be accurately calculated; Discretize the inviscid terms using the third-order MUSCL reconstruction format combined with the rotational Roe format to ensure high-precision calculation and improve numerical stability; Discretize the source terms to ensure that the influence of the source terms on the flow field during the calculation process is accurately incorporated; In each sub-iteration, gradually optimize the flow field calculation through pseudo-time step advancement.

6. The method according to claim 5, wherein The handling of the rotor-stator interface by the sliding mesh method and calculating the rotor and stator flows in the rotating and stationary reference frames respectively includes: When handling the rotor-stator interface, the grids on the rotor side rotate according to the physical angular velocity and time, and exchange the flow information of adjacent grids on both sides of the rotor-stator interface according to their instantaneous positions. Among them, the radial grid point distributions on both sides of the design-to-static interface are consistent, but the circumferential grid points are not restricted; only one-dimensional search is performed circumferentially to determine the grid adjacent relationship, and linear interpolation and reference frame conversion are carried out to complete the information exchange between the rotor and stator sides.

7. A full - circumference simulation device for unsteady flow of fan / compressor stator - rotor blade interaction, characterized in that, It includes: A preprocessing module for obtaining the three-dimensional geometry of a two-stage fan from the outside, generating a full-week grid through the three-dimensional geometry and specifying boundary conditions, and converting the generated grid file and boundary condition file into the input file format required for the flow solution process; A flow solution module for solving the unsteady Reynolds-averaged equations based on the full-week grid and boundary conditions after format conversion. Among them, the dual-time stepping method divides the solution process into two-layer iterations. The main iteration refers to the advancement of the physical time step, and the sub-iteration refers to the advancement of the pseudo-time step. During the sub-iteration solution process, the sliding grid method is used to handle the design-to-static interface; A post-processing module for, after the solution is completed, outputting the aerodynamic performance parameters of the fan in text format and outputting a three-dimensional transient flow data file in binary format.

8. An electronic device, characterized in that, It includes: A processor and a memory communicatively connected to the processor; The memory stores computer execution instructions; The processor executes the computer execution instructions stored in the memory to implement the method according to any one of claims 1-5.

9. A computer-readable storage medium, characterized in that, Computer execution instructions are stored in the computer-readable storage medium, and when the computer execution instructions are executed by the processor, they are used to implement the method according to any one of claims 1-5.

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