A method and device for matching the overall aerodynamic stability margin of a compressor

Abstract

This application discloses a stage matching method and apparatus for the overall aerodynamic stability margin of a compressor. By independently analyzing the influence of each stage matching in a multi-stage compressor on the overall aerodynamic stability margin without changing the influence of the system B parameter, it realizes single variable control and quantitative evaluation of stability margin, providing a reliable basis for stage matching optimization in compressor design, thereby realizing the rational design and adjustment of the matching relationship between compressor stages.

Description

Technical Field

[0001] This application relates to, but is not limited to, the field of aero-engine and gas turbine technology, and particularly to a stage matching method and apparatus for the overall aerodynamic stability margin of a compressor. Background Technology

[0002] The compressor is a key component of gas turbines and aero engines. The flow inside the compressor is subjected to a large adverse pressure gradient, which can sometimes cause the compressor to enter an unstable state. Compressor instability can cause many problems, such as blade breakage, overall vibration, and structural damage. To prevent compressor instability during operation, the compressor operating point is usually set far from the compressor instability boundary, i.e., a certain stability margin is provided.

[0003] With the increasing demand for high-load, high-performance designs, researchers are gradually adopting methods such as three-dimensional numerical simulation and low-dimensional models to study the aerodynamic matching characteristics between stages in multi-stage compressors and their impact on overall stability. Here, a stage refers to the smallest functional unit within the compressor that completes one compression cycle. However, existing analytical methods, when studying the impact of a particular stage on the overall aerodynamic stability of the compressor, typically involve deleting that stage for comparative calculations. This approach simultaneously alters the compressor's system parameters (such as the B parameter) and the inter-stage matching relationships, leading to interference from additional variables in the results and making it difficult to guarantee the uniqueness and certainty of the analytical results.

[0004] Therefore, how to accurately identify and quantify the impact of each stage in a multi-stage compressor on the overall aerodynamic stability without changing the system characteristics is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] This application provides a stage matching method and apparatus for the overall aerodynamic stability margin of a compressor, which can determine the influence of each stage matching in a multi-stage compressor on the overall aerodynamic stability without changing the influence of the system's B parameters, thereby realizing the rational design and adjustment of the matching relationship between compressor stages.

[0006] This invention provides a stage matching method for the overall aerodynamic stability margin of a compressor, comprising: Acquire aerodynamic characteristic data for each stage of the compressor, including pressure ratio-flow characteristic data and efficiency-flow characteristic data; While keeping the structure and characteristics of each stage of the compressor unchanged, the B parameters of the system are changed to determine the instability boundaries of each stage under different B parameters. Based on the instability boundaries of each level that are independent of the B parameter, multi-stage compressor configurations are formed by combining them step by step, and the instability boundaries independent of the B parameter under different matching configurations are determined. By comparing and analyzing the instability boundaries independent of the B parameter for single-stage and multi-stage configurations, the variation of the instability boundary at each stage is determined.

[0007] In one exemplary instance, it also includes: Based on the results of the comparative analysis, the direction and extent of the influence of each stage of the compressor on the overall aerodynamic stability margin after multi-stage matching are determined.

[0008] In one exemplary instance, the aerodynamic characteristic data of each stage of the compressor are obtained in any of the following ways: Three-dimensional numerical simulation, low-dimensional model calculation, and experimental testing.

[0009] In one exemplary instance, determining the instability boundaries at each level under different B parameters includes: While keeping the structural and operating parameters of the single-stage compressor unchanged, a corresponding compressor system model is established; By changing one of the system parameters in the compressor system model, the B parameter is adjusted to vary in different numerical ranges, and the instability boundary under different B parameters is calculated. As the B parameter gradually increases, if the instability boundary tends to stabilize and no longer changes with the B value, then the corresponding boundary is an instability boundary that is independent of the B parameter.

[0010] In one exemplary instance, determining the B-parameter-independent instability boundary under different matching configurations includes: Based on the obtained aerodynamic characteristic data and instability boundaries of each stage, the compressors are combined sequentially according to the order of the compressor stages to form a multi-stage compressor combination configuration. Each combination configuration keeps the structural parameters and characteristics of each stage unchanged, and only changes the system parameters to adjust the changes of the system B parameter in different value ranges. By changing one of the system parameters, the variation of parameter B in different numerical ranges is adjusted, and the instability boundary under different parameters B is calculated. As the B parameter increases, when the instability boundary curve tends to stabilize and no longer changes with the B value, this stable boundary is the instability boundary of this multi-stage combined configuration that is independent of the B parameter.

[0011] In one exemplary instance, the system parameters include: downstream cavity volume. equivalent length of pipe With equivalent area .

[0012] In one exemplary instance, the comparative analysis of the B-parameter-independent instability boundaries of single-stage and multi-stage configurations, determining the changes in the instability boundary at each stage, includes: For each stage of the compressor, plot the instability boundary curve of that stage in its individual operating state, as well as the instability boundary curve of that stage in the corresponding multi-stage combined configuration. The relative positions and trends of the single-stage instability boundary and the combined configuration instability boundary are compared to analyze the direction and magnitude of the instability boundary offset: if the flow rate of the combined configuration instability boundary increases relative to the single-stage boundary at the same pressure ratio, this stage has a positive effect on the overall stability after multi-stage matching; if the flow rate of the combined configuration instability boundary decreases relative to the single-stage boundary at the same pressure ratio, this stage has a negative effect on the overall stability after multi-stage matching. By comparing the changes in the instability boundary of different combinations, the contribution of each single stage to the stability evolution of the multi-stage system can be identified, and the changes in the overall instability boundary after the addition of each stage can be obtained.

[0013] In one exemplary instance, determining the direction and extent of the influence of each stage of the compressor on the overall aerodynamic stability margin after multi-stage matching includes: Using the overall instability boundary of the multi-stage compressor, which is independent of the B parameter, as a reference, when the system is operating near the overall instability critical point, the actual matching point of each stage compressor under this operating condition is extracted to determine the operating point of the multi-stage system. The matching point of each stage in the multi-stage system is compared with the instability boundary of that stage when it is working alone. If the matching point is located to the right of the single-stage instability boundary, then that stage has a positive effect on the overall aerodynamic stability in the multi-stage matching; if the matching point is located to the left of the single-stage instability boundary, then that stage has a negative effect on the overall aerodynamic stability in the multi-stage matching. By comparing the changes in mass flow rate and pressure ratio of each stage in the multi-stage matching state and the single-stage operating state, if the operating flow rate of a certain stage in the multi-stage matching state is significantly increased compared with the single-stage state, it indicates that the stage has a strong positive contribution to the stability margin of the system in the multi-stage system; if the operating flow rate is decreased compared with the single-stage state, it indicates that the stage has a negative effect on the stability of the system in the multi-stage system. Based on the calculation results, the stages that negatively affect the overall aerodynamic stability margin are identified, and the geometry or operating parameters of these stages are adjusted accordingly to improve the inter-stage matching characteristics and enhance the overall stability margin.

[0014] This application also provides a computer-readable storage medium storing computer-executable instructions for executing the stage matching method for the overall aerodynamic stability margin of the compressor as described in any of the above claims.

[0015] This application embodiment further provides a stage matching device for the overall aerodynamic stability margin of a compressor, including a memory and a processor, wherein the memory stores the following instructions executable by the processor: steps for performing the stage matching method for the overall aerodynamic stability margin of a compressor as described in any of the above claims.

[0016] This application embodiment independently analyzes the impact of each stage matching in a multi-stage compressor on the overall aerodynamic stability margin without changing the influence of system B parameters. It achieves single-variable control and quantitative evaluation of stability margin, providing a reliable basis for compressor stage matching optimization, thereby enabling reasonable design and adjustment of the matching relationship between compressor stages.

[0017] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0018] The accompanying drawings are used to provide a further understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0019] Figure 1 This is a schematic diagram illustrating the factors influencing the aerodynamic stability of the compressor in the embodiments of this application; Figure 2 This is a schematic diagram of typical compressor characteristic curves in the embodiments of this application; Figure 3 This is a flowchart illustrating the stage matching method for the overall aerodynamic stability margin of the compressor in the embodiments of this application; Figure 4 This is a schematic diagram of the steady-state characteristics at each stage and the instability boundary independent of the B parameter in the embodiments of this application; Figure 5 This is a schematic diagram illustrating the variation of the instability boundary with the B parameter when operating alone in an embodiment of this application. Figure 6 This is a schematic diagram of the instability boundary independent of the B parameter under different compressor configurations in the embodiments of this application; Figure 7 This is a schematic diagram of the composition of the stage matching device for the overall aerodynamic stability margin of the compressor in the embodiments of this application. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be arbitrarily combined with each other.

[0021] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0023] It is understood that the terms "first" and "second" used in this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0024] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0025] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0026] The steps illustrated in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases the steps shown or described may be performed in a different order than that presented here.

[0027] With technological advancements, compressor design is evolving towards higher load and higher performance, leading to increasing engineering demands for high-performance compressors. Designers are employing various methods and techniques to optimize compressor performance. For multi-stage compressors, not only is excellent performance required at each stage, but also good matching between them. If a stage in a multi-stage compressor can be identified that reduces the compressor's stability margin, targeted optimization of that stage or other stability-enhancing measures can be implemented to broaden the overall compressor's stability margin.

[0028] The aerodynamic stability of a multi-stage compressor is affected by a variety of factors, such as Figure 1 As shown. First, there are the pressurization characteristics of each stage of the compressor, which are closely related to design parameters, including hub ratio, aspect ratio, three-dimensional shape, and tip clearance. Different design parameters determine the compressor's pressure rise characteristic curve and instability mode, thus showing significant differences in the characteristics of the instability flow field. Second, there are the matching characteristics between the stages of the compressor. In a multi-stage compressor, if one stage becomes unstable first, it will cause flow disturbances and even instability propagation in its upstream and downstream stages, eventually leading to deep surge. Therefore, the matching condition between stages directly determines whether the entire compressor can achieve both high aerodynamic performance and sufficient stability margin. Finally, there are the overall characteristics of the compression system. Greitzer summarizes this as an influencing factor characterized by system parameter B, which reflects the combined effect of system volume, inertia, and flow channel characteristics on aerodynamic stability. These three aspects together determine the overall aerodynamic stability of a multi-stage compressor.

[0029] In analyzing the matching characteristics of each stage of a compressor, two main methods are used: one is based on three-dimensional numerical simulation, which establishes a multi-stage compressor model by solving the Navier-Stokes (NS) equations, calculates and analyzes the flow field near the instability point, and thus determines which stage will first enter the instability state; the other is based on low-dimensional models, which models each stage separately, removes a stage from the model, and compares it with the stability boundary of the complete compressor to evaluate the impact of that stage on the overall aerodynamic stability. However, both three-dimensional simulation and low-dimensional model methods have the same problem: researchers often study the impact on overall stability by deleting a corresponding stage from the model. However, this approach not only changes... Figure 1 The crucial factor of inter-stage matching, as shown, also causes changes in the system's B parameters. Therefore, by subtracting the aerodynamic stability difference obtained from a single stage, it's difficult to clearly distinguish its source—whether it's caused by changes in inter-stage matching or by changes in the system's B parameters. This introduces an additional interference factor, making it impossible to accurately study the single variable of stage matching, thus affecting the reliability and uniqueness of the analysis results.

[0030] The definition of parameter B in the compressor is shown in formula (1), where, The characteristic velocity is usually the tip linear velocity. Indicates the speed of sound. For equivalent area, For the equivalent length of the pipe, For cavity volume: (1) According to formula (1), characteristic velocity and cavity volume The larger, or the speed of sound Feature size , The smaller the value, the larger the B parameter. This shows that the B parameter is affected not only by the system's geometric parameters but also by the compressor's own pressure rise characteristics. For a single compressor, its design parameters and pressure rise characteristics are already determined, i.e., its characteristic velocity. speed of sound equivalent area It has been determined that the cavity volume can be changed. equivalent length of pipe To change the B parameter, many studies investigate its influence by altering the pipeline cavity system. By adding or removing characteristics of a stage in the depressurizer, both stage matching and the B parameter are changed, but no single variable is controlled; therefore, the impact of each factor on the instability boundary cannot be determined. Further analysis of the meaning and influence of the B parameter leads to the rewriting of formula (1) as formula (2): (2) In formula (2), The natural frequency of the compression system represents the properties of the compression system. The numerator of formula (2) represents the compressor's boosting capacity, while the denominator reflects the force required to excite the natural frequency in the piping system. Therefore, the B parameter actually represents the ratio of the compressor's own boosting capacity to the boosting capacity required to excite instability disturbances. The larger the B parameter, the easier it is to excite oscillations, that is, the easier it is to experience surge. As mentioned earlier, Greitzer's research pointed out that when the B parameter is greater than a certain critical value, the compressor directly enters surge, while when the B parameter is less than the critical value, the compressor first experiences stall. In other words, the B parameter has the function of characterizing the instability process. Figure 2 A schematic diagram of a typical compressor characteristic curve, such as Figure 2As shown, in a large B system, the compression system experiences surge at point A. In a small B system, the operating point moves beyond point A towards a smaller flow rate. The smaller the B parameter, the smaller the achievable instability boundary flow rate, as demonstrated in relevant literature; therefore, the B parameter is related to the instability boundary. The influence of the B parameter on the instability process and the instability boundary is essentially the same. In the near-instability condition of the small B system, the compressor experiences flow separation or rotational stall; however, since the compressor still maintains high performance and a stable operating state, it is considered that the compressor has not reached the instability boundary. Further reducing the valve position results in surge in the compression system, and the instability boundary becomes wider. The B parameter has a critical value in determining the type of instability, and its influence on the instability boundary also exhibits a critical effect. When the B parameter is greater than a certain critical value, the instability boundary does not change significantly with the B parameter. When the B parameter is less than the critical value, changing the B parameter will significantly affect the instability boundary. When studying the effects of interstage matching, it is necessary to control the instability characteristics to be unaffected by the B parameter. To ensure that the instability characteristics are unaffected by the B parameter, in this embodiment, the downstream cavity volume is changed to increase the B parameter beyond a critical value. At this point, the instability boundary of each stage is independent of the B parameter. Under these circumstances, the impact of the matching characteristics of each stage of the compressor on the overall stability of the compressor is investigated.

[0031] To determine the impact of stage matching on overall aerodynamic stability in a multi-stage compressor without altering the influence of system B parameters, thereby enabling the rational design and adjustment of inter-stage matching relationships, this application provides a stage matching method for the overall aerodynamic stability margin of the compressor. Figure 3 As shown, it may include: Step 300: Obtain aerodynamic characteristic data for each stage of the compressor, including pressure ratio-flow characteristic data and efficiency-flow data.

[0032] In one exemplary instance, it can be obtained in any of the following ways: Three-dimensional numerical simulation, such as based on the Navier-Stokes equations, is used to solve the compressor under steady-state and near-instability conditions to obtain characteristic data of each stage. Low-dimensional model calculations, such as using the Greitzer model or its improved models to establish low-dimensional compression system equations, obtain pressure ratio-flow rate relationship curves at each stage, and combine them with existing experimental data or empirical loss models to obtain the corresponding efficiency-flow rate relationship curves; Experimental tests, such as measuring the actual operating characteristics of the compressor under different tip linear velocities, inlet flow rates, and outlet pressures.

[0033] Step 301: While keeping the structure and characteristics of each stage of the compressor unchanged, change the B parameters of the system to determine the instability boundaries of each stage under different B parameters.

[0034] In one exemplary instance, step 301 may include: First, a single-stage compressor system model is established. While keeping the structural and operating parameters of this stage of compressor constant, a corresponding compressor system model is established. System parameters may include the downstream cavity volume. equivalent length of pipe With equivalent area .

[0035] Then, as shown in formula (2), by changing the volume of the downstream cavity... equivalent length of pipe or equivalent area Adjust the B parameter to vary within different value ranges.

[0036] Next, the instability boundary is calculated under different B parameters. For each B value, the steady-state characteristic curve of the compressor at different flow rates is calculated using three-dimensional numerical simulation, low-dimensional model simulation, or experimental methods. The critical points for flow separation, rotating stall, or surge are determined, and the corresponding pressure ratio-flow rate coordinates are recorded to form the instability boundary curve.

[0037] Finally, the instability boundary independent of the B parameter is determined. As the B parameter gradually increases, if the instability boundary tends to stabilize and no longer changes with the B value, then the corresponding boundary is defined as the instability boundary independent of the B parameter. This boundary represents the inherent aerodynamic limit of the compressor stage when its instability characteristics are not affected by the system's B parameter.

[0038] Step 301 yielded the instability characteristics of each stage of the compressor under different B parameters, and extracted the instability boundaries of each stage that are independent of the B parameters.

[0039] In one embodiment, for a certain stage of the compressor, the volume of the downstream cavity can be increased. By increasing the system's B-parameters, the instability boundary of each stage is obtained under different B-parameter conditions. When the B-parameters increase to a certain critical value, the instability boundary of that stage compressor does not change; this boundary is considered an instability boundary independent of the B-parameters. Here, to obtain the critical instability point (i.e., instability boundary) of each stage compressor under different B-parameter conditions, three different techniques can be used: three-dimensional numerical simulation, low-dimensional model simulation, or physical experiments.

[0040] Step 302: Based on the instability boundaries of each stage that are independent of the B parameter, multi-stage compressor configurations are formed by combining them step by step to determine the instability boundaries of different matching configurations that are independent of the B parameter.

[0041] In one exemplary implementation, this step may include: First, a multi-stage compressor configuration model is established. Based on the obtained aerodynamic characteristic data and instability boundaries of each stage, the compressor stages are sequentially combined to form multi-stage compressor configuration models for the first two stages, the first three stages, and eventually the entire compressor (referred to as different-stage matching configurations). Each combination configuration maintains the structural parameters and characteristics of each stage unchanged, only changing the system parameters (such as the downstream cavity volume). equivalent length of pipe With equivalent area This is used to adjust the variation of system parameter B within different numerical ranges.

[0042] Then, according to formula (2), by changing, for example, increasing the volume of the downstream cavity. Or reduce the equivalent length of the pipeline equivalent area The system's B parameter is gradually increased through various methods. When the B parameter increases above the critical value determined in step 301, the system's instability boundary will no longer change with B.

[0043] Next, the instability boundary of the multi-stage configuration under different B parameters is calculated. For each combination configuration, calculations or experiments are performed at different B parameter values ​​to obtain the steady-state characteristic curves of the compressor at each B value, and the critical points of flow separation, rotating stall, or surge are identified. The corresponding pressure ratio-flow rate coordinates are the instability boundary of the multi-stage configuration under that B parameter.

[0044] Finally, the instability boundary independent of the B parameter is determined for different stage matching configurations. As the B parameter increases, the instability boundary curve tends to stabilize and no longer changes with the B value; this stable boundary is defined as the B parameter independent instability boundary for this multistage configuration. This instability boundary reflects the inherent aerodynamic limit of the multistage compressor under the condition that the influence of the B parameter is eliminated.

[0045] In one embodiment, the first and second stages of the compressor can be connected first, increasing the downstream cavity volume. By increasing the system's B-parameter to a critical value, the instability boundary of this combined configuration, independent of the B-parameter, is obtained. Then, by adding a third stage, a fourth stage, and so on, the above process is repeated to obtain the instability boundaries of the first two stages, the first three stages, and ultimately the entire compressor stage, respectively, independent of the B-parameter. Similarly, the instability boundaries of different stage combined configurations independent of the B-parameter can be obtained through any of the following methods: three-dimensional numerical simulation, low-dimensional simulation, or experimental testing.

[0046] Step 302 yielded the instability characteristics of each multi-stage compressor configuration under different B-parameter conditions, and extracted the instability boundary of each configuration independent of the B-parameter.

[0047] Step 303: Compare and analyze the instability boundaries independent of the B parameter for single-stage and multi-stage configurations to determine the changes in the instability boundary at each stage.

[0048] This step compares the B-parameter-independent instability boundary of the multi-stage configuration with the B-parameter-independent instability boundary of each compressor stage. By comparing the relative positions and trends of the instability boundaries in the pressure ratio-flow rate coordinate system for single-stage and multi-stage configurations, the direction and extent of each stage's influence on overall aerodynamic stability after multi-stage matching are determined. The analysis results of step 303 reveal the stability evolution characteristics during the multi-stage matching process of the compressor.

[0049] In one exemplary instance, step 303 may include: First, for each compressor stage, the instability boundary curve of that stage under individual operating conditions is plotted, as well as the instability boundary curve of that stage in the corresponding multi-stage combined configuration (such as 1A+2A, 1A+2A+3A, etc.). In one embodiment, the instability boundary can be represented using a pressure ratio-flow rate or normalized mass flow rate-pressure ratio coordinate system.

[0050] Then, the relative positions and trends of the single-stage instability boundary and the combined configuration instability boundary are compared to analyze the direction and magnitude of the instability boundary offset: if the instability boundary of the combined configuration moves to the right relative to the single-stage boundary (the flow rate increases at the same pressure ratio), it indicates that the stage has broadened the stability margin of the system after multi-stage matching, that is, it has a positive effect on the overall stability; if the instability boundary of the combined configuration moves to the left relative to the single-stage boundary (the flow rate decreases at the same pressure ratio), it indicates that the stage has narrowed the stability margin of the system after multi-stage matching, that is, it has a negative effect on the overall stability.

[0051] Next, by comparing the changes in instability boundaries of different combinations (first two stages, first three stages, whole system, etc.), the contribution of each single stage to the stability evolution of the multi-stage system is identified, and the changes in the overall instability boundary after each stage is added are obtained.

[0052] The stage matching method for overall aerodynamic stability margin of compressors provided in this application analyzes the influence of each stage matching in a multi-stage compressor on the overall aerodynamic stability margin independently without changing the influence of system B parameters. This achieves single-variable control and quantitative evaluation of stability margin, providing a reliable basis for stage matching optimization in compressor design, thereby enabling reasonable design and adjustment of the matching relationship between compressor stages.

[0053] In one exemplary instance, the stage matching method for the overall aerodynamic stability margin of a compressor provided in this application embodiment may further include: Step 304: Based on the comparison results, determine the direction and extent of the influence of each stage of the compressor on the overall aerodynamic stability margin after multi-stage matching.

[0054] In one exemplary implementation, this step may include: First, taking the overall instability boundary of the multi-stage compressor, which is independent of the B parameter, as a reference, when the system is operating near the overall instability critical point, the actual matching point of each stage compressor under this operating condition (i.e., the flow and pressure ratio operating state of each stage) is extracted to determine the operating point of the multi-stage system.

[0055] Next, determine the relative position of the single-stage matching point. Compare the matching point of each stage in the multi-stage system with the instability boundary of that stage when it operates alone. If the matching point is located to the right of the single-stage instability boundary (i.e., the flow rate is larger at the same pressure ratio), it indicates that the stage has widened the stable operating range of the system in multi-stage matching, and has a positive effect on the overall aerodynamic stability. If the matching point is located to the left of the single-stage instability boundary (i.e., the flow rate is smaller at the same pressure ratio), it indicates that the stage has narrowed the stable operating range of the system, and has a negative effect on the overall aerodynamic stability.

[0056] Next, the impact of each compressor stage on the overall aerodynamic stability margin after multi-stage matching is calculated. To quantitatively describe the impact of each stage on the stability margin, the relative offset direction and magnitude can be determined by comparing the changes in mass flow rate and pressure ratio of each stage in the multi-stage matched state and in the single-stage operating state. Specifically, if the operating flow rate of a certain stage in the multi-stage matched state is significantly increased compared to the single-stage state, it indicates that this stage increases the overall instability boundary flow rate in the multi-stage system, making a strong positive contribution to the system stability margin; if the operating flow rate is decreased compared to the single-stage state, it indicates that this stage enters the instability region earlier in the multi-stage system, having a negative effect on system stability. By comparing the magnitude of this relative offset, the impact of each stage on the overall aerodynamic stability margin can be quantitatively determined.

[0057] Finally, based on the calculation results, the stages that negatively affect the overall aerodynamic stability margin are identified, and the geometric or operating parameters of these stages (such as tip clearance, aspect ratio, guide vane angle, etc.) are adjusted accordingly to improve inter-stage matching characteristics and enhance the overall stability margin.

[0058] Step 304 quantitatively determines the direction and extent of the effect of each stage of matching on the overall aerodynamic stability margin of the compressor, providing a direct basis for stability matching and structural optimization in the design of multi-stage compressors.

[0059] Compared with related technologies, the embodiments of this application decouple the compressor stage matching from the influence of B-parameters on compressor stability. This ensures that the compressor instability boundary is no longer disturbed by changes in B-parameters, allowing for the independent study of the true impact of the matching relationship between different compressor stages on the overall compressor aerodynamic stability. By obtaining the instability boundaries of each stage and different multi-stage configurations when the B-parameters reach critical values, the embodiments of this application explicitly eliminate the influence of factors such as system cavity volume and pipe dimensions on instability characteristics, achieving stability analysis conditions for a single variable. This decoupling method proposed in the embodiments of this application is a key technical feature of the invention, ensuring the reliability and uniqueness of the inter-stage matching analysis results.

[0060] This application also provides a general method for obtaining an instability boundary independent of the B parameter. Specifically, by increasing the downstream cavity volume to raise the B parameter above a critical value, the instability boundary can be fixed. Furthermore, according to the definition of the B parameter, for compressors of the same speed and configuration, the B parameter can also be raised above a critical value by reducing the system piping flow area or the equivalent pipe length. All of these methods enable the compressor to enter a large B-parameter system, ensuring that the instability boundary does not change with variations in the B parameter, thereby obtaining the compressor's inherent aerodynamic stability limit. This method described in this application is simple to implement and highly applicable.

[0061] Based on this, the embodiments of this application enable independent analysis of the stability contribution of each compressor stage in a multi-stage matching system. By comparing the instability boundary of each stage operating independently with its instability boundary in a multi-stage combined configuration, the offset pattern of the instability boundary of different stages under multi-stage conditions is clearly observed. If the matching point of a stage in the multi-stage system is to the right of its single-stage instability boundary, it indicates that the stage has a positive effect of widening the overall stability margin after multi-stage matching; if the matching point is to the left, it indicates that the stage will compress the stable operating range of the system, which is a negative effect. This criterion proposed in the embodiments of this application is clear and operable, and can be directly used to determine the direction and strength of the influence of each stage on the overall stability margin.

[0062] The analysis method described in this application quickly identifies weak stages that limit the overall aerodynamic stability margin, providing a basis for inter-stage matching optimization in compressor design. Designers can then make targeted improvements to stages with negative effects, such as adjusting tip clearance, optimizing three-dimensional aerodynamic design, changing aspect ratio or guide vane angle, to improve the overall stability and performance of the compressor. In summary, the embodiments of this application not only accurately assess the aerodynamic stability contribution of each stage within a multi-stage compressor but also effectively support engineering optimization, significantly improving the matching quality and operational stability margin of the compressor.

[0063] This application also provides a computer-readable storage medium storing computer-executable instructions for performing the stage matching method for the overall aerodynamic stability margin of a compressor as described in any of the preceding claims.

[0064] This application further provides a stage matching device for the overall aerodynamic stability margin of a compressor, including a memory and a processor, wherein the memory stores the following instructions executable by the processor: steps for performing the stage matching method for the overall aerodynamic stability margin of the compressor as described in any of the above claims.

[0065] The following uses a three-stage compressor as an example, with the three stages being: stage 1 (1A), stage 2 (2A), and stage 3 (3A), to explain in detail the stage matching method for the overall aerodynamic stability margin of the compressor in the embodiments of this application.

[0066] First, obtain the aerodynamic characteristic lines of each stage of the three-stage compressor, such as... Figure 4 As shown, the steady-state characteristic curves of the three stages of the compressor and the instability boundary locations when each stage operates independently are displayed. Figure 4 The left figure shows the pressure ratio-flow steady-state characteristic curve of stage 1 (1A) (as shown by the solid curve) and its instability boundary (as shown by the circled mark). Similarly, Figure 4 The middle figure shows the steady-state characteristic line and instability boundary of level 2 (2A). Figure 4 The figure on the right shows the steady-state characteristic curves and instability boundaries of level 3 (3A). These characteristic curves can be obtained through 3D simulation, low-dimensional model simulation, or experimental testing.

[0067] Then, the instability boundaries of each stage under different B parameters are determined. Figure 5 Taking the relationship between the instability boundary and the B parameter when 1A operates alone as an example, such as Figure 5 As shown, from point A to point C and finally to point D, the parameter B gradually increases. When the parameter B increases to point C, the instability boundary of 1A remains basically unchanged (as shown). Figure 5 The horizontal segment C–D in the diagram indicates that after this point, the instability boundary of a single-stage 1A is independent of the B parameter, and its corresponding instability boundary is as follows: Figure 4 As shown by the circles in the left figure, the circled instability boundary is the intrinsic instability boundary of 1A, independent of the B parameter. Using the same method, the B parameter-independent instability boundaries of 2A and 3A can be obtained respectively, as shown in the figure. Figure 4 China Library and Figure 4 As shown in the figure on the right.

[0068] Next, the instability boundaries of the multi-stage compressor configuration, independent of the B-parameter, are calculated. After obtaining the instability boundaries of each individual stage, the individual stage models are combined stage by stage: Combination 1: 1A + 2A (first two stage configuration), Combination 2: 1A + 2A + 3A (entire stage configuration). By increasing the downstream cavity volume and other methods, the system B-parameter is increased to above the critical value. Calculations or experiments are performed on different combination configurations to obtain the instability boundaries of the two multi-stage configurations, independent of the B-parameter. Figure 6 The steady-state characteristic lines of 1A, 2A, and 3A under different configurations and their instability boundaries in multi-level configurations are shown as follows: Figure 6 The circles, triangles, and squares in the diagram are shown.

[0069] Next, comparing the instability boundaries of single-stage and multi-stage configurations, the single-stage instability boundary is as follows: Figure 4 As indicated by the circled markings, the instability boundary under a multi-level configuration is as follows: Figure 6 As indicated by the triangles and squares, the offset direction and magnitude of the instability boundaries at each stage after the addition of the multi-stage matching structure can be observed through comparison. The comparison results are as follows: For 1A, after the addition of 2A and 3A, the instability boundary of 1A moves to the right (the flow rate increases under the same pressure ratio), indicating that the downstream stage reduces the stability margin of 1A; For 2A, after the addition of 1A, its instability boundary shifts significantly to the left, and the stability margin decreases, but after the addition of 3A, its instability boundary shifts to the right again, and the stability margin is partially restored; For 3A, after the addition of 1A+2A, its instability boundary shifts to the right as a whole, indicating that the upstream stage improves the stability margin of 3A.

[0070] based on Figure 6 The comparison leads to the following conclusions: For stage 1 (1A), its instability boundary is pushed to the right in a multi-stage system, indicating that the presence of subsequent stages reduces its available stability margin. However, from the perspective of the entire system, 1A has a positive effect on the overall stability margin (overall boundary shifts to the right). For stage 2 (2A), the stability margin is significantly reduced (shifted to the left) after adding 1A. Although the subsequent addition of 3A provides some improvement, it is still generally biased to the left. Therefore, 2A has a negative effect on the overall stability margin. For stage 3 (3A), the addition of 1A and 2A results in a significant shift to the right, indicating that the upstream stages improve its stability. Therefore, 3A has a positive effect on the overall stability margin. In summary, in this embodiment, 1A and 3A make a positive contribution to improving the overall compressor stability margin; 2A has a negative effect on the overall stability margin and is the stage that needs to be optimized.

[0071] As can be seen from this embodiment, the stage matching method for the overall aerodynamic stability margin of the compressor provided in this application, through a step-by-step combination analysis from single-stage to multi-stage, achieves independent discrimination of the influence of each stage matching on the overall aerodynamic stability margin after successfully decoupling the influence of the B parameter. The results clearly reveal the stability contribution of different stages in a multi-stage compressor, providing a reliable basis for weak stage identification and stage matching optimization in engineering design.

[0072] Figure 7 This is a schematic diagram of the composition of the stage matching device for the overall aerodynamic stability margin of the compressor in the embodiments of this application, as shown below. Figure 7 As shown, it may include: an acquisition module, a first determination module, a second determination module, and a comparison module. The acquisition module is used to acquire aerodynamic characteristic data of each stage of the compressor, including pressure ratio-flow characteristic data and efficiency-flow characteristic data; The first determining module is used to determine the instability boundary of each stage under different B parameters by changing the B parameters of the system while keeping the structure and characteristics of each stage of the compressor unchanged. The second determining module is used to determine the instability boundaries independent of B parameters under different matching configurations by combining the instability boundaries of each level in a multi-stage compressor configuration. The comparison module is used to compare and analyze the instability boundaries independent of the B parameter in single-stage and multi-stage configurations, and to determine the changes in the instability boundary at each stage. The stage matching device for the overall aerodynamic stability margin of the compressor provided in this application embodiment independently analyzes the influence of each stage matching in a multi-stage compressor on the overall aerodynamic stability margin without changing the influence of system B parameters. It realizes single variable control and quantitative evaluation of stability margin, providing a reliable basis for stage matching optimization in compressor design, thereby realizing the reasonable design and adjustment of the matching relationship between compressor stages.

[0073] The processing module is used to determine the direction and extent of the influence of each stage of the compressor on the overall aerodynamic stability margin after multi-stage matching, based on the comparison results.

[0074] Compared with related technologies, the embodiments of this application decouple stage matching from the influence of B parameters on compressor stability, thereby allowing for the independent study of the impact of matching between each stage of the compressor on its aerodynamic stability. Through analysis and comparison, the embodiments of this application can determine the influence of each individual stage of the compressor on the overall aerodynamic stability of the compressor. This conclusion can help compressor designers quickly identify a weak stage in the design, enabling targeted optimization and improvement, and ultimately enhancing compressor performance.

[0075] Although the embodiments disclosed in this application are as described above, the content described is merely for the purpose of understanding this application and is not intended to limit this application. Any person skilled in the art to which this application pertains may make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in this application; however, the scope of patent protection of this application shall still be determined by the scope defined in the appended claims.

Claims

1. A method of matching the overall aerodynamic stability margin of a compressor stages, characterized in that, include: Acquire aerodynamic characteristic data for each stage of the compressor, including pressure ratio-flow characteristic data and efficiency-flow characteristic data; While keeping the structure and characteristics of each stage of the compressor unchanged, the B parameters of the system are changed to determine the instability boundaries of each stage under different B parameters; among them, the instability boundary that tends to be stable and no longer changes with the B value as the B parameter increases is the instability boundary that is independent of the B parameter. Based on the instability boundaries of each level that are independent of the B parameter, multi-stage compressor configurations are formed by combining them step by step, and the instability boundaries independent of the B parameter under different matching configurations are determined. By comparing and analyzing the instability boundaries independent of the B parameter for single-stage and multi-stage configurations, the variation of the instability boundary at each stage is determined. Based on the results of the comparative analysis, the direction and extent of the influence of each stage of the compressor on the overall aerodynamic stability margin after multi-stage matching are determined.

2. The level matching method according to claim 1, wherein, The aerodynamic characteristic data of each stage of the compressor can be obtained in any of the following ways: Three-dimensional numerical simulation, low-dimensional model calculation, and experimental testing.

3. The level matching method according to claim 1, wherein, Determining the instability boundaries at each level under different B parameters includes: While keeping the structural and operating parameters of the single-stage compressor unchanged, a corresponding compressor system model is established; By changing a system parameter in the compressor system model, the B parameter is adjusted to vary within different numerical ranges, and the instability boundary under the different B parameters is calculated.

4. The level matching method according to claim 1, wherein, The determination of the B-parameter-independent instability boundary under different matching configurations includes: Based on the obtained aerodynamic characteristic data and instability boundaries of each stage, the compressors are combined sequentially according to the order of the compressor stages to form a multi-stage compressor combination configuration. Each combination configuration keeps the structural parameters and characteristics of each stage unchanged, and only changes the system parameters to adjust the changes of the system B parameter in different value ranges. By changing one of the system parameters, the variation of parameter B in different numerical ranges is adjusted, and the instability boundary under different parameters B is calculated. As the B parameter increases, when the instability boundary curve tends to stabilize and no longer changes with the B value, this stable instability boundary is the instability boundary of the multi-stage compressor configuration that is independent of the B parameter.

5. The level matching method according to claim 3 or 4, wherein, The system parameters include: downstream cavity volume equivalent length of pipe With equivalent area .

6. The level matching method according to claim 1, wherein, The comparative analysis of the B-parameter-independent instability boundaries of single-stage and multi-stage configurations determines the variation of the instability boundary at each stage, including: For each stage of the compressor, plot the instability boundary curve of that stage in its standalone operating state, as well as the instability boundary curve of that stage in the corresponding multi-stage combined configuration. The relative positions and trends of the single-stage instability boundary and the combined configuration instability boundary are compared to analyze the direction and magnitude of the instability boundary offset: if the flow rate of the combined configuration instability boundary increases relative to the single-stage boundary at the same pressure ratio, this stage has a positive effect on the overall stability after multi-stage matching; if the flow rate of the combined configuration instability boundary decreases relative to the single-stage boundary at the same pressure ratio, this stage has a negative effect on the overall stability after multi-stage matching. By comparing the changes in the instability boundary of different combinations, the contribution of each single stage to the stability evolution of the multi-stage system is identified, and the changes in the overall instability boundary after the addition of each stage are obtained.

7. The level matching method according to claim 1, wherein, The determination of the direction and extent of the influence of each stage of the compressor on the overall aerodynamic stability margin after multi-stage matching includes: Using the overall instability boundary of the multi-stage compressor, which is independent of the B parameter, as a reference, when the system is operating near the overall instability critical point, the actual matching point of each stage compressor under this operating condition is extracted to determine the operating point of the multi-stage system. The matching point of each stage in the multi-stage system is compared with the instability boundary of that stage when it is working alone. If the matching point is located to the right of the single-stage instability boundary, then that stage has a positive effect on the overall aerodynamic stability in the multi-stage matching; if the matching point is located to the left of the single-stage instability boundary, then that stage has a negative effect on the overall aerodynamic stability in the multi-stage matching. By comparing the changes in mass flow rate and pressure ratio of each stage in the multi-stage matching state and the single-stage operating state, if the operating flow rate of a certain stage in the multi-stage matching state is significantly increased compared with the single-stage state, it indicates that the stage has a strong positive contribution to the stability margin of the system in the multi-stage system; if the operating flow rate is decreased compared with the single-stage state, it indicates that the stage has a negative effect on the stability of the system in the multi-stage system. Based on the calculation results, the stages that negatively affect the overall aerodynamic stability margin are identified, and the geometry or operating parameters of these stages are adjusted accordingly to improve the inter-stage matching characteristics and enhance the overall stability margin.

8. A computer-readable storage medium storing computer-executable instructions for performing the stage matching method for overall aerodynamic stability margin of a compressor as described in any one of claims 1-7.

9. A stage matching device for overall aerodynamic stability margin of a compressor, comprising a memory and a processor, wherein, The memory stores the following instructions that can be executed by the processor: steps for performing the stage matching method for the overall aerodynamic stability margin of the compressor as described in any one of claims 1-7.

Images