A method and system for high-efficiency numerical simulation of full-ring unsteady multi-stage axial compressor

Abstract

The invention relates to the technical field of computational fluid dynamics, and in particular to a method and system for unsteady and efficient numerical simulation of the whole ring of a multi-stage axial flow compressor. The method comprises the following steps: steady calculation of the grid flow field of a single channel of the whole stage to obtain single channel data of each stage; periodically copying the single channel data of the i-th stage as a whole ring to obtain the i-th stage full ring data; combining the i-th stage full ring data with the single channel data of the remaining stages downstream thereof, and unsteady calculation to obtain the i-th stage full ring data information; periodically copying the single channel data of the i+1-th stage as a whole ring to obtain the i+1-th stage full ring data; combining the i+1-th stage full ring data with the single channel data of the remaining stages downstream thereof, and using the i-th stage outlet full ring flow field data as the i+1-th stage full ring inlet boundary, and unsteady calculation to obtain the i+1-th stage full ring data information; and sequentially obtaining and combining the full ring data information within the remaining stages of the single channel period to obtain the unsteady data of the whole stage full ring.

Description

Technical Field

[0001] The present invention relates to the technical field of computational fluid dynamics, and in particular to a method and system for highly efficient full-ring unsteady numerical simulation of a multi-stage axial flow compressor. Background Art

[0002] Multi-stage axial flow compressors are widely used in the aerospace field, such as aircraft engines and gas turbines. Due to the relative rotation of the moving and stationary blades, wake interference, secondary flow and other reasons, the flow inside the compressor has a strong unsteady characteristic. Therefore, the unsteady characteristic is of great significance to the aerodynamic performance and stability of the compressor. At present, the numerical simulation method of turbomachinery has the advantages of short time consumption, low cost, and the ability to reveal the complex unsteady flow details inside the compressor. It is widely used in the design and analysis of compressors.

[0003] At present, the main numerical simulation methods for turbomachinery are: mixed plane method, blade reduction method, time tilt method, phase delay method, harmonic balance method, nonlinear harmonic method and full ring unsteady method. The mixed plane method simplifies the unsteady calculation into a steady calculation for a single flow channel, but it cannot capture the unsteady phenomena in the flow channel. The blade reduction method has poor simulation accuracy because it changes the actual geometric parameters. The time tilt method is highly dependent on the circumferential Mach number of the flow field and is limited by the ratio of the number of blades in adjacent rows. The phase delay method can only simulate the flow of two rows of blades and is not applicable to the flow field simulation of multi-stage blades. For the unsteady flow of multiple fundamental frequencies, the solution stability and efficiency of the harmonic balance method are limited by the sampling time. The nonlinear harmonic method depends on the pre-set frequency and is less applicable to the combined simulation of unknown frequency flow and multiple frequencies. The full ring unsteady method uses full ring meshing for the entire stage of the turbomachinery and performs unsteady calculations. It has the characteristics of high fidelity and nonlinearity and is the most direct and accurate method.

[0004] However, the full-ring unsteady method has the following problems: Since the number of compressor stages and blades is usually large, the number of grids calculated at one time can reach hundreds of millions, resulting in large memory consumption; the number of grids in the entire full ring is large, and the number of steps required to achieve flow field convergence is large, resulting in a long calculation time; too many grids require a large number of parallel computing cores, and errors may continue to accumulate during the parallel computing process, causing the calculation to easily diverge. Therefore, the existing full-ring unsteady method has the problems of large memory consumption, long calculation time and unstable calculation. Summary of the invention

[0005] The purpose of the present invention is to provide a multi-stage axial flow compressor full-loop unsteady high-efficiency numerical simulation method to solve the problems of large memory consumption, long calculation time and unstable calculation in the full-loop unsteady method in the prior art.

[0006] In order to solve the above problems, the present invention proposes a multi-stage axial flow compressor full-ring unsteady high-efficiency numerical simulation method, and the technical solution adopted is:

[0007] A multi-stage axial flow compressor full-ring unsteady high-efficiency numerical simulation method comprises the following steps:

[0008] Step S1, the flow field of the whole-level single-channel grid is calculated steadily until the flow field converges, and the single-channel data of each level is extracted and stored separately, wherein the single-channel data of each level includes n levels of single-channel data, and the single-channel data includes a single-channel grid and corresponding flow field data, wherein n is an integer ≥ 3;

[0009] Step S2, periodically copying the i-th level single channel data into a full ring, obtaining the i-th level full ring grid and corresponding flow field data, recorded as the i-th level full ring data, where i=1;

[0010] Step S3, combining the i-th level full-ring data with the single-channel data of the remaining levels downstream thereof, performing unsteady calculation until the flow field converges, and obtaining the full-ring data information within the i-th level single-channel cycle, wherein the full-ring data information within the i-th level single-channel cycle includes the i-th level outlet full-ring flow field data;

[0011] Step S4, periodically copying the i+1th level single channel data into a full ring, obtaining the i+1th level full ring grid and corresponding flow field data, recorded as the i+1th level full ring data;

[0012] Step S5, combining the i+1th level full ring data with the single channel data of the remaining levels downstream thereof, and using the i-th level outlet full ring flow field data as the i+1th level full ring inlet boundary condition, performing unsteady calculation until the flow field converges, and obtaining the full ring data information within the i+1th level single channel period, wherein the full ring data information within the i+1th level single channel period includes the i+1th level outlet full ring flow field data;

[0013] Step S6, i is recorded as i+1, and steps S4 and S5 are repeated until i=n, ​​and the full-loop data information in the single-channel cycle of the remaining levels is obtained in sequence;

[0014] Step S7, combining the full-loop data information within each level of single-channel cycles to obtain the full-loop unsteady data of the entire level.

[0015] Furthermore, in step S1, the step of calculating the flow field of the entire single-channel grid at a steady state until the flow field converges includes:

[0016] The model grid is divided and the model parameters are set according to the working conditions under study, and the mixed plane method is used to calculate the steady-state flow field of the entire single-channel grid until the flow field converges.

[0017] Furthermore, in step S2, the i-th level single channel data is periodically copied into a full ring to obtain the i-th level full ring grid and corresponding flow field data, including:

[0018] The grid and flow field data of the stationary blade row and the moving blade row in the i-th level single-channel grid are periodically replicated respectively to obtain the full-ring stationary blade row flow field data and the full-ring moving blade row flow field data; then the full-ring stationary blade row flow field data and the full-ring moving blade row flow field data are combined to form the i-th level full-ring grid and the corresponding flow field data.

[0019] Furthermore, the flow field data refers to the flow field value at the center of each single-channel grid; the flow field value includes a pressure value, a velocity value and a temperature value.

[0020] Furthermore, in step S3, the full-loop data of the i-th level is combined with the single-channel data of the remaining levels downstream thereof, and the unsteady calculation is performed until the flow field converges to obtain the full-loop data information within the i-th level single-channel period, including:

[0021] The i-th level full-loop data is combined with the single-channel data of the remaining levels downstream, the simulation time step is set according to the operating speed, and unsteady calculation is performed; when the unsteady calculation reaches the i-th level full-loop data, which is continuous and has periodic variation characteristics, it is considered that the unsteady calculation converges to the flow field, and then the full-loop data information within the i-th level single channel period is obtained.

[0022] Furthermore, when the unsteady calculation reaches the i-th level full-loop data, which is continuous and has periodic variation characteristics, it is considered that the unsteady calculation reaches the flow field convergence, and then the full-loop data information within the i-th level single channel period is obtained, including:

[0023] When the unsteady calculation reaches the i-th level full-ring data that is continuous and has periodic variation characteristics, it is considered that the unsteady calculation reaches the convergence of the flow field. Then, the time for the moving blades to rotate a single channel is calculated according to the operating speed and the number of moving blades on the moving blade row in the i-th level full-ring grid, and the i-th level single-channel cycle and the full-ring data information of each time step in the single-channel cycle are obtained, and then the full-ring data information within the i-th level single-channel cycle is obtained.

[0024] Furthermore, the full-circle flow field data of the i-th stage outlet includes: full-circle grid three-dimensional coordinate information, velocity field information, pressure field information and temperature field information at the i-th stage outlet plane.

[0025] Further, in step S5, the step of using the full-ring flow field data at the i-th level outlet as the i+1-th level full-ring inlet boundary condition includes:

[0026] The full circulation field data of the i-th level outlet is cyclically assigned to the i+1-th level inlet by using a cyclic assignment method.

[0027] Furthermore, in step S7, the full-loop data information in each level of single-channel cycle is combined to obtain the full-loop unsteady data of the entire level, including:

[0028] The corresponding relationship between the cycle assignment time of the full-ring flow field data at the previous level outlet in each level and the time of obtaining the corresponding full-ring data information within the single-channel cycle of each level after convergence is counted in turn, and the flow field time relationship of the full ring at each level is established; according to the flow field time relationship of the full ring at each level, the unsteady data of the full ring of the entire level is obtained.

[0029] The present invention also provides a system for executing the above-mentioned multi-stage axial flow compressor full-ring unsteady high-efficiency numerical simulation method, comprising:

[0030] The single-channel grid processing module is used to calculate the flow field of the entire single-channel grid steadily until the flow field converges, and to extract and store the single-channel data of each level separately. The single-channel data of each level includes n levels of single-channel data. The single-channel data includes the single-channel grid and the corresponding flow field data, where n is an integer ≥ 3;

[0031] The i-th level full ring data acquisition module is used to periodically copy the i-th level single channel data into a full ring to obtain the i-th level full ring grid and the corresponding flow field data, which are recorded as the i-th level full ring data, where i=1;

[0032] The full-ring data information acquisition module within the i-th level single-channel cycle is used to combine the i-th level full-ring data with the single-channel data of the remaining levels downstream thereof, and perform unsteady calculations until the flow field converges to obtain the full-ring data information within the i-th level single-channel cycle, wherein the full-ring data information within the i-th level single-channel cycle includes the i-th level outlet full-ring flow field data;

[0033] The i+1th level full ring data acquisition module is used to periodically copy the i+1th level single channel data into a full ring to obtain the i+1th level full ring grid and corresponding flow field data, which are recorded as the i+1th level full ring data;

[0034] The full-ring data information acquisition module within the i+1-stage single-channel cycle is used to combine the i+1-stage full-ring data with the single-channel data of the remaining stages downstream thereof, and use the i-stage outlet full-ring flow field data as the i+1-stage full-ring inlet boundary condition, perform unsteady calculation until the flow field converges, and obtain the full-ring data information within the i+1-stage single-channel cycle, wherein the full-ring data information within the i+1-stage single-channel cycle includes the i+1-stage outlet full-ring flow field data;

[0035] The remaining full-ring data acquisition modules at all levels, denoted as i+1, are used to cycle the i+1th level full-ring data acquisition module and the i+1th level full-ring data information acquisition module within the single-channel cycle, until i=n, ​​and sequentially obtain the full-ring data information within the single-channel cycles of the remaining levels;

[0036] The whole-level full-loop unsteady data acquisition module is used to combine the full-loop data information within each level of single-channel cycle to obtain the whole-level full-loop unsteady data.

[0037] Beneficial effect: The present invention is an improved invention. Compared with the whole-stage full-ring grid calculation, the multi-stage axial compressor full-ring unsteady efficient numerical simulation method of the present invention has a small amount of calculation grid and low memory consumption; wherein, the steady-state calculation result of the whole-stage single-channel grid flow field is used as the initial field of the unsteady calculation, which can reduce the number of iterations required for the convergence of the unsteady calculation, and the grid amount of the step-by-step calculation is small, the calculation time is short, and the calculation efficiency is high; the method has a small demand for computing resources, can reduce the number of parallel computing cores, effectively avoid the numerical divergence problem caused by a large number of cores, and the calculation is more stable.

[0038] In step S1, the step of calculating the flow field of the entire single-channel grid at a steady state until the flow field converges includes:

[0039] The model grid is divided and the model parameters are set according to the working conditions under study, and the mixed plane method is used to calculate the steady-state flow field of the entire single-channel grid until the flow field converges, ensuring that the flow field data of each stage extracted separately are the same as the data of each stage in the single-channel entire stage flow field.

[0040] In step S3, the full-loop data of the i-th level is combined with the single-channel data of the remaining levels downstream thereof, and the unsteady calculation is performed until the flow field converges to obtain the full-loop data information within the i-th level single-channel period, including:

[0041] Combine the i-th level full ring data with the single channel data of the remaining levels downstream, set the simulation time step according to the operating speed, and perform unsteady calculations; when the unsteady calculation reaches the i-th level full ring data, which is continuous and has periodic variation characteristics, it is considered that the unsteady calculation converges to the flow field, and then obtains the full ring data information within the i-th level single channel period. In the above method, since only the i-th level is a full ring grid and the remaining levels are single channel grids, the grid size is small and the memory usage is small compared to the whole level full ring calculation.

[0042] When the unsteady calculation reaches the i-th level full-loop data, which is continuous and has periodic variation characteristics, it is considered that the unsteady calculation reaches the flow field convergence, and then the full-loop data information within the i-th level single channel period is obtained, including:

[0043] When the unsteady calculation reaches the i-th level full-ring data that is continuous and has periodic variation characteristics, it is considered that the unsteady calculation reaches the flow field convergence. Then, the time for the moving blades to rotate a single channel is calculated according to the operating speed and the number of moving blades on the moving blade row in the i-th level full-ring grid to obtain the i-th level single-channel period, and the full-ring data information for each time step within the single-channel period is obtained, thereby obtaining the full-ring data information within the i-th level single-channel period, so that the full-ring flow field data information within the i-th level single-channel period is more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic flow chart of a multi-stage axial flow compressor full-ring unsteady high-efficiency numerical simulation method of the present invention;

[0045] Figure 2 It is a schematic diagram of a whole-stage single-channel grid in the multi-stage axial flow compressor full-ring unsteady high-efficiency numerical simulation method of the present invention;

[0046] Figure 3 It is a schematic diagram of the first-stage full-ring grid and other-stage single-channel grids in the multi-stage axial compressor full-ring unsteady high-efficiency numerical simulation method of the present invention;

[0047] Figure 4 1 is a schematic diagram of the full annular flow field data at the first stage outlet in the full annular unsteady high-efficiency numerical simulation method for a multi-stage axial flow compressor of the present invention, wherein (a) is the temperature field, (b) is the pressure field, and (c) is the velocity field;

[0048] Figure 5 Schematic diagram of the boundary conditions of the second stage full ring inlet in the multi-stage axial flow compressor full ring unsteady high-efficiency numerical simulation method of the present invention, wherein (a) is the temperature field, (b) is the pressure field, and (c) is the velocity field;

[0049] Figure 6 It is a velocity field result diagram of the whole-stage full-loop unsteady data obtained by the multi-stage axial flow compressor full-loop unsteady high-efficiency numerical simulation method of the present invention;

[0050] Figure 7 It is a pressure field result diagram of the whole-stage full-ring unsteady data obtained by the multi-stage axial flow compressor full-ring unsteady high-efficiency numerical simulation method of the present invention;

[0051] Figure 8 It is a temperature field result diagram of the whole-stage full-ring unsteady data obtained by the multi-stage axial flow compressor full-ring unsteady high-efficiency numerical simulation method of the present invention;

[0052] Fig. 9 This is the velocity field result diagram of the flow field obtained by the traditional full-loop unsteady numerical simulation method;

[0053] Fig.10This is the pressure field result diagram of the flow field obtained by the traditional full-loop unsteady numerical simulation method;

[0054] Fig.11 This is the temperature field result diagram of the flow field obtained by the traditional full-ring unsteady numerical simulation method. DETAILED DESCRIPTION

[0055] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0056] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0057] The following describes the full-ring unsteady and efficient numerical simulation method and system for a multi-stage axial flow compressor according to an embodiment of the present application with reference to the accompanying drawings.

[0058] Combine the following Figure 1 , the full-ring unsteady and efficient numerical simulation method for a multi-stage axial flow compressor provided in this application is described in detail.

[0059] Step S1, the flow field of the whole level single-channel grid is calculated steadily until the flow field converges, and the single-channel data of each level is extracted and stored separately, wherein the single-channel data of each level includes n levels of single-channel data, and the single-channel data includes a single-channel grid and corresponding flow field data, wherein n is an integer ≥3.

[0060] Specifically, the steady-state calculation of the flow field of the entire single-channel grid is performed until the flow field converges, including: model grid division and model parameter setting for the operating point under study, and the mixed plane method is used to perform the steady-state calculation of the flow field of the entire single-channel grid until the flow field converges. The mixed plane method is one of the single-channel steady-state calculation methods and is the most widely used compressor flow field simulation algorithm. The single-channel grids of each level and the corresponding flow field data are extracted and stored independently to ensure that the separately extracted flow field data of each level is the same as the data of each level in the single-channel entire level flow field.

[0061] In this embodiment, a certain type of three-stage axial flow compressor is taken as an example, but the present invention is not limited thereto. In practical applications, corresponding components to be simulated are selected according to actual conditions. Figure 2 As shown in the figure, the compressor has 3 stages, that is, n is 3; each stage consists of a stationary blade row and a moving blade row, and the whole stage has 6 blade rows. The mixed plane method is used to calculate the single-channel grid flow field, and the 3-level single-channel grids and corresponding flow field data are extracted and stored.

[0062] Step S2: Periodically copy the i-th level single-channel data into a full ring to obtain the i-th level full ring grid and the corresponding flow field data, which are recorded as the i-th level full ring data, where i=1.

[0063] Specifically, the i-th level single-channel data is periodically copied into a full ring to obtain the i-th level full-ring grid and corresponding flow field data, including: periodically copying the grid and flow field data of the stationary blade row and the moving blade row in the i-th level single-channel grid, respectively, to obtain the full-ring stationary blade row flow field data and the full-ring moving blade row flow field data; and then combining the full-ring stationary blade row flow field data and the full-ring moving blade row flow field data to form the i-th level full-ring grid and corresponding flow field data. Here, the flow field data refers to the flow field value at the center of each single-channel grid; wherein the flow field value includes pressure value, velocity value and temperature value. It should be noted that the flow field value is not limited to pressure value, velocity value and temperature value, but can also be an entropy field value, as long as it can characterize the indicator of the flow field.

[0064] For example, in a certain type of three-stage axial flow compressor in step S1, since the number of blades in the stationary blade row and the moving blade row of each stage is different, the grid and flow field data of the stationary blade row and the moving blade row of each stage are periodically replicated to obtain full-ring stationary blade row flow field data and full-ring moving blade row flow field data; then the full-ring stationary blade row flow field data and the full-ring moving blade row flow field data are combined to form the first-level full-ring grid and the corresponding flow field data, that is, the first-level full-ring data.

[0065] Step S3, combining the full-ring data of the i-th level with the single-channel data of the remaining levels downstream thereof, performing unsteady calculation until the flow field converges, and obtaining the full-ring data information within the i-th level single-channel cycle, wherein the full-ring data information within the i-th level single-channel cycle includes the full-ring flow field data of the i-th level outlet.

[0066] Specifically, the i-th level full ring data is combined with the single-channel data of the remaining levels downstream, and the unsteady calculation is performed until the flow field converges to obtain the full ring data information within the i-th level single channel cycle, including: combining the i-th level full ring data with the single-channel data of the remaining levels downstream, setting the simulation time step according to the operating speed, and performing unsteady calculation; when the unsteady calculation is continuous and has periodic change characteristics to the i-th level full ring data, it is considered that the unsteady calculation is converged to the flow field, and then the full ring data information within the i-th level single channel cycle is obtained. Here, the i-th level outlet full ring flow field data includes: full ring grid three-dimensional coordinate information, velocity field information, pressure field information and temperature field information. It should be noted that when the unsteady calculation is continuous to the i-th level full ring data, it means that the velocity field information, pressure field information and temperature field information at the interface of the moving and stationary blade rows are continuous; having periodic change characteristics means that the velocity field information, pressure field information and temperature field information have periodic changes.

[0067] Among them, when the unsteady calculation is continuous to the i-th level full-ring data and has periodic change characteristics, it is considered that the unsteady calculation is converged to the flow field, and then the full-ring data information within the i-th level single-channel period is obtained, including: when the unsteady calculation is continuous to the i-th level full-ring data and has periodic change characteristics, it is considered that the unsteady calculation is converged to the flow field, and then, the time for the moving blades to rotate a single channel is calculated according to the operating speed and the number of moving blades on the moving blade row in the i-th level full-ring grid, and the i-th level single-channel period and the full-ring data information of each time step in the single-channel period are obtained, and then the full-ring data information within the i-th level single-channel period is obtained.

[0068] For example, in a certain type of three-stage axial flow compressor in step S1, Figure 3 As shown, the first-level full-ring data obtained in step S2 is combined with the single-channel data of the second level and the single-channel data of the third level, and the simulation time step is reasonably set according to the operating speed to ensure the stability of the unsteady calculation. When the unsteady calculation reaches the first-level full-ring data, which is continuous and has periodic variation characteristics, it is considered that the unsteady calculation flow field converges. After the first-level unsteady calculation flow field converges, the time for the moving blade to rotate a single channel is calculated according to the operating speed and the number of moving blades on the moving blade row in the first-level full-ring grid, and the first-level single-channel cycle and the full-ring data information of each time step in the single-channel cycle are obtained, and the full-ring data information of each time step in the single-channel cycle is recorded and stored, so as to obtain the full-ring data information in the first-level single-channel cycle. Since only the first level is a full-ring grid, and the second and third levels are single-channel grids, the grid volume is small and the memory usage is small compared to the whole-level full-ring calculation.

[0069] Step S4, periodically copy the i+1th level single-channel data into a full ring to obtain the i+1th level full ring grid and corresponding flow field data, which are recorded as the i+1th level full ring data.

[0070] Specifically, the i+1-th level single-channel data is periodically copied into a full ring to obtain the i+1-th level full-ring grid and corresponding flow field data, which are recorded as the i+1-th level full-ring data, including: periodically copying the grid and flow field data of the stationary blade row and the moving blade row in the i+1-th level single-channel grid respectively to obtain the full-ring stationary blade row flow field data and the full-ring moving blade row flow field data; and then combining the full-ring stationary blade row flow field data and the full-ring moving blade row flow field data to form the i+1-th level full-ring grid and corresponding flow field data.

[0071] Step S5, combining the i+1-level full-ring data with the single-channel data of the remaining levels downstream thereof, and using the i-level outlet full-ring flow field data as the i+1-level full-ring inlet boundary condition, performing unsteady calculation until the flow field converges, and obtaining the full-ring data information within the i+1-level single-channel cycle, wherein the full-ring data information within the i+1-level single-channel cycle includes the i+1-level outlet full-ring flow field data. Here, using the i-level outlet full-ring flow field data as the i+1-level full-ring inlet boundary condition includes: using a cyclic assignment method to cyclically assign the i-level outlet full-ring flow field data to the i+1-level inlet.

[0072] For example, in a certain type of three-stage axial compressor in step S1, the second-stage full-ring data is combined with the third-stage single-channel data, and the first-stage outlet full-ring flow field data is extracted. Here, the first-stage outlet full-ring flow field data includes: full-ring grid three-dimensional coordinate information, velocity field information, pressure field information, and temperature field information at the first-stage outlet plane. Figure 4 , 5 As shown, the full-ring flow field data at the first-stage outlet is cyclically assigned to the second-stage inlet. When the unsteady calculation reaches the second-stage full-ring data, which is continuous and has periodic variation characteristics, the unsteady calculation flow field is considered to have converged. At this time, since only the second stage is a full-ring grid, the first-stage full-ring data is not considered and the third stage is only a single-channel grid, the grid volume is small and the memory usage is small compared to the whole-stage full-ring calculation. After the unsteady calculation flow field of the second-stage full-ring grid converges, the time for the moving blade to rotate a single channel is calculated according to the operating speed and the number of moving blades on the moving blade row in the second-stage full-ring grid, and the single-channel cycle of the second stage and the full-ring data information of each time step in the single-channel cycle are obtained, and the full-ring data information of each time step in the single-channel cycle is recorded and stored, thereby obtaining the full-ring data information in the second-stage single-channel cycle; at the same time, the corresponding relationship between the cyclic assignment time of the full-ring flow field data at the first-stage outlet and the time of obtaining the corresponding full-ring data information in the second-stage single-channel cycle after convergence is established.

[0073] Step S6, i is recorded as i+1, and steps S4 and S5 are repeated until i=n, ​​and the full-circle flow field data information within the single-channel cycle of the remaining levels is obtained in sequence;

[0074] For example, in a certain type of three-stage axial flow compressor in step S1, steps S4 and S5 are looped, and the third-stage single-channel data is periodically copied to the full ring to obtain the third-stage full-ring grid and the corresponding flow field data, which are recorded as the third-stage full-ring data. The second-stage outlet full-ring flow field data is cyclically assigned to the third-stage inlet. When the unsteady calculation reaches the third-stage full-ring data, which is continuous and has periodic variation characteristics, the unsteady calculation flow field is considered to converge. After the unsteady computational flow field of the third-level single-channel grid converges, the time for the blades to rotate a single channel is calculated according to the operating speed and the number of blades on the blade row in the third-level full-ring grid, and the third-level single-channel cycle and the full-ring data information of each time step in the single-channel cycle are obtained. The full-ring data information of each time step in the single-channel cycle is recorded and stored, and then the full-ring data information in the third-level single-channel cycle is obtained. At the same time, the corresponding relationship between the cycle assignment time of the full-ring flow field data at the second-level outlet and the time of obtaining the corresponding full-ring data information in the third-level single-channel cycle after convergence is established.

[0075] Step S7, combining the full-loop data information within each level of single-channel cycles to obtain the full-loop unsteady data of the entire level.

[0076] Specifically, the correspondence between the cycle assignment time of the full-ring flow field data at the previous level outlet in each level and the time of obtaining the corresponding full-ring data information within the single-channel cycle of each level after convergence is counted in turn, and the flow field time relationship of the full ring at each level is established; according to the flow field time relationship of the full ring at each level, the unsteady data of the full ring of the entire level is obtained.

[0077] For example, in a certain type of three-stage axial flow compressor in step S1, according to the corresponding relationship between the cycle assignment time of the full-ring flow field data at the first-stage outlet obtained in step S5 and the time of obtaining the corresponding full-ring data information within the second-stage single-channel cycle after convergence, and the corresponding relationship between the cycle assignment time of the full-ring flow field data at the second-stage outlet obtained in step S6 and the time of obtaining the corresponding full-ring data information within the third-stage single-channel cycle after convergence, the flow field time relationship of the first, second and third stages is established. Figure 6 , 7 As shown in Figures 8 and 8, based on the established flow field time relationship of the 1st, 2nd and 3rd level full ring, the whole level full ring unsteady data is obtained, that is, the velocity field result diagram, pressure field result diagram and temperature field result diagram of the whole level full ring unsteady data.

[0078] Here, if Fig. 9 , 10As shown in Figures 11, the velocity field result diagram, pressure field result diagram and temperature field result diagram obtained by the traditional full-loop unsteady numerical simulation method are compared with the velocity field result diagram, pressure field result diagram and temperature field result diagram obtained by the multi-stage axial flow compressor full-loop unsteady high-efficiency numerical simulation method of the present application. It can be seen that the whole-stage full-loop unsteady data calculated by the multi-stage axial flow compressor full-loop unsteady high-efficiency numerical simulation method of the present application and the traditional full-loop unsteady numerical simulation method are basically consistent. Therefore, the multi-stage axial flow compressor full-loop unsteady high-efficiency numerical simulation method of the present application is a full-loop unsteady high-efficiency method with high precision. At the same time, under the premise of using the same computing resources, the calculation time of the traditional full-loop unsteady numerical simulation method is 37 hours, while the calculation time of the multi-stage axial flow compressor full-loop unsteady high-efficiency numerical simulation method of the present application is 26 hours. It can be seen that the multi-stage axial flow compressor full-loop unsteady high-efficiency numerical simulation method of the present application has the characteristic of short time consumption.

[0079] The present application also provides a system for executing the above-mentioned multi-stage axial flow compressor full-ring unsteady high-efficiency numerical simulation method, comprising:

[0080] The single-channel grid processing module is used to calculate the flow field of the entire single-channel grid steadily until the flow field converges, and to extract and store the single-channel data of each level separately. The single-channel data of each level includes n levels of single-channel data. The single-channel data includes the single-channel grid and the corresponding flow field data, where n is an integer ≥ 3;

[0081] The i-th level full ring data acquisition module is used to periodically copy the i-th level single channel data into a full ring to obtain the i-th level full ring grid and the corresponding flow field data, which are recorded as the i-th level full ring data, where i=1;

[0082] The full-ring data information acquisition module within the i-th level single-channel cycle is used to combine the i-th level full-ring data with the single-channel data of the remaining levels downstream thereof, and perform unsteady calculations until the flow field converges to obtain the full-ring data information within the i-th level single-channel cycle, wherein the full-ring data information within the i-th level single-channel cycle includes the i-th level outlet full-ring flow field data;

[0083] The i+1th level full ring data acquisition module is used to periodically copy the i+1th level single channel data into a full ring to obtain the i+1th level full ring grid and corresponding flow field data, which are recorded as the i+1th level full ring data;

[0084] The full-ring data information acquisition module within the i+1-stage single-channel cycle is used to combine the i+1-stage full-ring data with the single-channel data of the remaining stages downstream thereof, and use the i-stage outlet full-ring flow field data as the i+1-stage full-ring inlet boundary condition, perform unsteady calculation until the flow field converges, and obtain the full-ring data information within the i+1-stage single-channel cycle, wherein the full-ring data information within the i+1-stage single-channel cycle includes the i+1-stage outlet full-ring flow field data;

[0085] The remaining full-ring data acquisition modules at all levels, denoted as i+1, are used to cycle the i+1th level full-ring data acquisition module and the i+1th level full-ring data information acquisition module within the single-channel cycle, until i=n, ​​and sequentially obtain the full-ring data information within the single-channel cycles of the remaining levels;

[0086] The whole-level full-loop unsteady data acquisition module is used to combine the full-loop data information within each level of single-channel cycle to obtain the whole-level full-loop unsteady data.

[0087] Here, those skilled in the art will appreciate that the specific method of the multi-stage axial flow compressor full-ring unsteady high-efficiency numerical simulation system has been described in the reference above. Figures 1 to 8 The method has been introduced in detail in the description of the full-ring unsteady and efficient numerical simulation method of a multi-stage axial flow compressor, so its repeated description will be omitted.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention shall be based on the claims. All equivalent structural changes made using the contents of the description and drawings of the present invention should also be included in the protection scope of the present invention.

Claims

1. A multi-stage axial flow compressor full-ring unsteady high-efficiency numerical simulation method, characterized in that: The following steps are involved: Step S1, the flow field of the whole-level single-channel grid is calculated steadily until the flow field converges, and the single-channel data of each level is extracted and stored separately, wherein the single-channel data of each level includes n levels of single-channel data, and the single-channel data includes a single-channel grid and corresponding flow field data, wherein n is an integer ≥ 3; Step S2, periodically copying the i-th level single channel data into a full ring, obtaining the i-th level full ring grid and corresponding flow field data, recorded as the i-th level full ring data, where i=1; Step S3, combining the i-th level full-ring data with the single-channel data of the remaining levels downstream thereof, performing unsteady calculation until the flow field converges, and obtaining the full-ring data information within the i-th level single-channel cycle, wherein the full-ring data information within the i-th level single-channel cycle includes the i-th level outlet full-ring flow field data; Step S4, periodically copying the i+1th level single channel data into a full ring, obtaining the i+1th level full ring grid and corresponding flow field data, recorded as the i+1th level full ring data; Step S5, combining the i+1th level full ring data with the single channel data of the remaining levels downstream thereof, and using the i-th level outlet full ring flow field data as the i+1th level full ring inlet boundary condition, performing unsteady calculation until the flow field converges, and obtaining the full ring data information within the i+1th level single channel period, wherein the full ring data information within the i+1th level single channel period includes the i+1th level outlet full ring flow field data; Step S6, i is recorded as i+1, and steps S4 and S5 are repeated until i=n, ​​and the full-loop data information in the single-channel cycle of the remaining levels is obtained in sequence; Step S7, combining the full-loop data information within each level of single-channel cycles to obtain the full-loop unsteady data of the entire level.

2. The multi-stage axial flow compressor full-ring unsteady high-efficiency numerical simulation method according to claim 1 is characterized in that: In step S1, the step of calculating the flow field of the entire single-channel grid at a steady state until the flow field converges includes: The model grid is divided and the model parameters are set according to the working conditions under study, and the mixed plane method is used to calculate the steady-state flow field of the entire single-channel grid until the flow field converges.

3. The multi-stage axial flow compressor full-ring unsteady high-efficiency numerical simulation method according to claim 1 is characterized in that: In step S2, the i-th level single channel data is periodically copied into a full ring to obtain the i-th level full ring grid and the corresponding flow field data, including: The grid and flow field data of the stationary blade row and the moving blade row in the i-th level single-channel grid are periodically replicated respectively to obtain the full-ring stationary blade row flow field data and the full-ring moving blade row flow field data; then the full-ring stationary blade row flow field data and the full-ring moving blade row flow field data are combined to form the i-th level full-ring grid and the corresponding flow field data.

4. The method for full-ring unsteady high-efficiency numerical simulation of a multi-stage axial flow compressor according to claim 3 is characterized in that: The flow field data refers to the flow field value at the center of each single channel grid; the flow field value includes pressure value, velocity value and temperature value.

5. The multi-stage axial flow compressor full-ring unsteady high-efficiency numerical simulation method according to claim 1 is characterized in that: In step S3, the full-loop data of the i-th level is combined with the single-channel data of the remaining levels downstream thereof, and the unsteady calculation is performed until the flow field converges to obtain the full-loop data information within the i-th level single-channel period, including: The i-th level full-loop data is combined with the single-channel data of the remaining levels downstream, the simulation time step is set according to the operating speed, and unsteady calculation is performed; when the unsteady calculation reaches the i-th level full-loop data, which is continuous and has periodic variation characteristics, it is considered that the unsteady calculation converges to the flow field, and then the full-loop data information within the i-th level single channel period is obtained.

6. The multi-stage axial flow compressor full-ring unsteady high-efficiency numerical simulation method according to claim 5 is characterized in that: When the unsteady calculation reaches the i-th level full-loop data, which is continuous and has periodic variation characteristics, it is considered that the unsteady calculation reaches the flow field convergence, and then the full-loop data information within the i-th level single channel period is obtained, including: When the unsteady calculation reaches the i-th level full-ring data that is continuous and has periodic variation characteristics, it is considered that the unsteady calculation reaches the convergence of the flow field. Then, the time for the moving blades to rotate a single channel is calculated according to the operating speed and the number of moving blades on the moving blade row in the i-th level full-ring grid, and the i-th level single-channel cycle and the full-ring data information of each time step in the single-channel cycle are obtained, and then the full-ring data information within the i-th level single-channel cycle is obtained.

7. The method for full-ring unsteady high-efficiency numerical simulation of a multi-stage axial flow compressor according to claim 1 is characterized in that: The full-circle flow field data of the i-th stage outlet includes: full-circle grid three-dimensional coordinate information, velocity field information, pressure field information and temperature field information at the i-th stage outlet plane.

8. The multi-stage axial flow compressor full-ring unsteady high-efficiency numerical simulation method according to claim 1 is characterized in that: In step S5, the step of using the full-ring flow field data at the i-th level outlet as the i+1-th level full-ring inlet boundary condition includes: The full circulation field data of the i-th level outlet is cyclically assigned to the i+1-th level inlet by using a cyclic assignment method.

9. The method for full-ring unsteady high-efficiency numerical simulation of a multi-stage axial flow compressor according to claim 8, characterized in that: In step S7, the full-loop data information in each level of single-channel cycle is combined to obtain the full-loop unsteady data of the entire level, including: The corresponding relationship between the cycle assignment time of the full-ring flow field data at the previous level outlet in each level and the time of obtaining the corresponding full-ring data information within the single-channel cycle of each level after convergence is counted in turn, and the flow field time relationship of the full ring at each level is established; according to the flow field time relationship of the full ring at each level, the unsteady data of the full ring of the entire level is obtained.

10. A system for executing the multi-stage axial flow compressor full-ring unsteady high-efficiency numerical simulation method as claimed in any one of claims 1 to 9, characterized in that: include: The single-channel grid processing module is used to calculate the flow field of the entire single-channel grid steadily until the flow field converges, and to extract and store the single-channel data of each level separately. The single-channel data of each level includes n levels of single-channel data. The single-channel data includes the single-channel grid and the corresponding flow field data, where n is an integer ≥ 3; The i-th level full ring data acquisition module is used to periodically copy the i-th level single channel data into a full ring to obtain the i-th level full ring grid and the corresponding flow field data, which are recorded as the i-th level full ring data, where i=1; The full-ring data information acquisition module within the i-th level single-channel cycle is used to combine the i-th level full-ring data with the single-channel data of the remaining levels downstream thereof, and perform unsteady calculations until the flow field converges to obtain the full-ring data information within the i-th level single-channel cycle, wherein the full-ring data information within the i-th level single-channel cycle includes the i-th level outlet full-ring flow field data; The i+1th level full ring data acquisition module is used to periodically copy the i+1th level single channel data into a full ring, obtain the i+1th level full ring grid and corresponding flow field data, which are recorded as the i+1th level full ring data; The full-ring data information acquisition module within the i+1-stage single-channel cycle is used to combine the i+1-stage full-ring data with the single-channel data of the remaining stages downstream thereof, and use the i-stage outlet full-ring flow field data as the i+1-stage full-ring inlet boundary condition, perform unsteady calculation until the flow field converges, and obtain the full-ring data information within the i+1-stage single-channel cycle, wherein the full-ring data information within the i+1-stage single-channel cycle includes the i+1-stage outlet full-ring flow field data; The remaining full-ring data acquisition modules at all levels, denoted as i+1, are used to cycle the i+1th level full-ring data acquisition module and the i+1th level full-ring data information acquisition module within the single-channel cycle, until i=n, ​​and sequentially obtain the full-ring data information within the single-channel cycles of the remaining levels; The whole-level full-loop unsteady data acquisition module is used to combine the full-loop data information within each level of single-channel cycle to obtain the whole-level full-loop unsteady data.

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