Variable cycle compression system test matching characteristic modeling method

Abstract

The application provides a variable cycle compression system test matching characteristic modeling method, comprising: establishing an aerodynamic performance surface domain characteristic map of the variable cycle compression system, wherein the horizontal coordinate of the aerodynamic performance surface domain characteristic map is the conversion flow of the variable cycle compression system, and the vertical coordinate is the bypass ratio or the bypass non-dimensional back pressure; extracting a key element curve in the aerodynamic performance surface domain characteristic map; determining a bypass ratio or a bypass non-dimensional back pressure range to be analyzed in the aerodynamic performance surface domain characteristic map; extracting several compressor or fan aerodynamic performance characteristic curves from the stall point to the surge point when the bypass ratio or the bypass non-dimensional back pressure is unchanged along the fixed condition of the characteristic parameter in the bypass ratio or the bypass non-dimensional back pressure range; extracting the working point characteristic parameter, the surge point characteristic parameter and the surge margin of each compressor or fan aerodynamic performance characteristic curve; and respectively establishing the change curves of the working point characteristic parameter, the surge point characteristic parameter and the surge margin with the bypass ratio or the bypass non-dimensional back pressure, and fitting.

Description

Technical Field

[0001] This application belongs to the field of aero-engine technology, and specifically relates to a method for modeling the test matching characteristics of a variable cycle compression system. Background Technology

[0002] Adaptive variable cycle engines have multiple operating modes and complex characteristics. Their compression components can include a three-duct adaptive fan and a variable cycle dual-duct compressor. To adapt to the multi-operation mode requirements of the engine, the aerodynamics and structure of the compression system or components of the adaptive variable cycle engine have undergone significant changes compared to conventional fans or compressors.

[0003] like Figure 1 The schematic diagram of a typical adaptive three-duct fan is shown. The adaptive three-duct fan 10 includes, in sequence, adjustable blades 11, a front fan rotor 12, a front fan stator 13, a rear fan rotor 14, and a rear fan stator 16. There is a duct between the front fan stator 13 and the rear fan rotor 14, which forms a third duct 19. A flow divider ring 17 is set after the rear fan stator 16. The flow divider ring 17 divides the main fan duct into an inner duct 16 and an outer duct 18, thereby forming a three-duct structure.

[0004] like Figure 2 The schematic diagram of a typical variable cycle dual-bypass compressor is shown. The variable cycle dual-bypass compressor 20 includes, in sequence, adjustable blades 21, core engine drive fan rotor 22, core engine drive fan stator 23, compressor rotor 24 and compressor stator 25. There is a duct between the core engine drive fan stator 23 and the compressor rotor 24, which forms the front bypass 27. The compressor outlet 26 is located behind the compressor stator 25, forming the rear bypass 27.

[0005] like Figure 3 The schematic diagram illustrating the impact of the third duct back pressure on the adaptive fan performance in the illustrated embodiment illustrates the strong coupling between the adaptive fan / compressor performance and the aerodynamic environment of the third / front duct. This results in fan or compressor performance varying over a wide range under different matching conditions, posing significant technical challenges to the performance optimization of adaptive fans and variable-cycle compressors, particularly in the matching and use of components within the entire engine. Currently, because adaptive compression systems are heavily influenced by duct characteristics, component testing often focuses on a few duct conditions, conducting aerodynamic performance measurements primarily to verify simulation calculations. There is a lack of effective methods to directly establish a method based on component test data that can effectively support component performance matching under the overall engine operating environment. Summary of the Invention

[0006] The purpose of this application is to provide a method for modeling the test matching characteristics of a variable cyclic compression system to solve or mitigate at least one of the problems in the background art.

[0007] The technical solution of the present application is: a variable cycle compression system test matching characteristic modeling method, comprising:

[0008] An aerodynamic performance surface domain feature map of the variable cycle compression system is established, the horizontal coordinate of the aerodynamic performance surface domain feature map is the conversion flow of the variable cycle compression system, and the vertical coordinate is a characteristic parameter of a third channel of a self-adaptive three-channel fan or a front channel of a variable cycle compressor, the characteristic parameter is a channel ratio or a channel dimensionless back pressure;

[0009] Key element curves are extracted from the aerodynamic performance surface domain feature map of the variable cycle compression system;

[0010] The channel ratio or channel dimensionless back pressure range to be analyzed is determined in the aerodynamic performance surface domain feature map;

[0011] In the channel ratio or channel dimensionless back pressure range, a plurality of compressor or fan aerodynamic performance characteristic curves from the choke point to the surge point under the condition of fixed characteristic parameters are extracted;

[0012] The working point characteristic parameter, the surge point characteristic parameter and the surge margin of each compressor or fan aerodynamic performance characteristic curve are extracted;

[0013] The curves of the working point characteristic parameter, the surge point characteristic parameter and the surge margin changing with the channel ratio or the channel dimensionless back pressure are respectively established, and are fitted into a model to obtain the matching aerodynamic performance characteristic curve of the variable cycle compression system.

[0014] Further, the key element curves include the working line, the highest efficiency line or the highest pressure ratio line and the surge boundary line.

[0015] Further, the extracted compressor or fan aerodynamic performance characteristic curves are not less than 4.

[0016] Further, the working point characteristic parameter and the surge point characteristic parameter include the pressure ratio, the flow rate and the efficiency.

[0017] Further, the fitting process adopts a quadratic relationship: F=m(B) 2 +n(B)+p

[0018] In the formula, F is the working point characteristic parameter, the surge point characteristic parameter or the surge margin, B is the channel ratio or the channel dimensionless back pressure, m, n and p are coefficients, which change with the test object and the speed state.

[0019] The method of the application can establish a model of the influence of the variable of the duct ratio on the aerodynamic performance of the adaptive compression system based on the component test data, so as to quantitatively evaluate the change law of the performance parameters of the working point, surge and other key states of the compression system with the characteristic variable of the duct ratio, thereby effectively guiding the matching adjustment and use of the component under the condition of the aero-engine whole machine. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions provided by the application, the following will briefly introduce the drawings. Obviously, the drawings described below are only some embodiments of the application.

[0021] Figure 1 It is a schematic diagram of the adaptive three-duct fan structure.

[0022] Figure 2 It is a schematic diagram of the variable cycle two-duct compressor structure.

[0023] Figure 3 It is a schematic diagram of the influence of the third-duct environment back pressure on the performance of the adaptive three-duct fan of an embodiment.

[0024] Figure 4 It is a flowchart of the variable cycle compression system test matching characteristic modeling method in the application.

[0025] Figure 5 It is a schematic diagram of the aerodynamic performance surface domain characteristic of an embodiment of the application.

[0026] Figure 6 It is a compression system characteristic curve extracted along the fixed-duct characteristic variable in an embodiment of the application. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the application more clear, the technical solutions in the embodiments of the application will be described in more detail below with reference to the drawings in the embodiments of the application.

[0028] In view of the current problem that the component test data cannot support the performance matching of the component under the working environment of the whole machine, the application provides a modeling method of the variable cycle compression system test matching characteristic based on the component test data, which solves the matching problem of the adaptive compression system under the working environment of the whole machine.

[0029] As shown in Figure 4 The modeling method of the adaptive compression system matching characteristic based on the test performance provided by the application includes the following steps:

[0030] S1, a surface domain characteristic diagram representing the aerodynamic performance of the adaptive variable cycle compression system is established by a test method, so as to form an aerodynamic performance surface domain 30 of the adaptive variable cycle compression system, as shown in Figure 5As shown in the figure, the abscissa of the aerodynamic performance surface domain characteristic map is the converted flow rate m of the adaptive variable cycle compression system, and the ordinate is the characteristic parameter of the third channel or the front channel of the variable cycle compressor, i.e., the channel ratio or the channel dimensionless back pressure B.

[0031] S2, extracting a key element curve in the aerodynamic performance surface domain characteristic map, such as Figure 5 As shown in the figure, the key element curve includes the working line 31, the highest efficiency line / highest pressure ratio line 32 and the surge boundary line 33.

[0032] S3, determining the channel ratio or channel dimensionless back pressure range that needs to be analyzed in the surface domain characteristic map, such as Figure 5 As shown in the figure, the channel ratio or channel dimensionless back pressure range that needs to be analyzed in the surface domain characteristic map is the range between the fixed channel characteristic variable curves 34 and 35.

[0033] S4, in the determined channel ratio or channel dimensionless back pressure range, extracting not less than 4 channel ratio or channel dimensionless back pressure constant performance characteristic curves of the compressor or fan from the choke point to the surge point under the condition of the fixed channel characteristic variable, wherein the channel ratio or channel dimensionless back pressure of each extracted compressor or fan performance characteristic curve covers the parameter range as evenly as possible. As shown in the figure, Figure 5 The fixed channel characteristic variable curve 36 in the figure is one of the extracted compressor or fan performance characteristic curves, and Figure 6 As shown in the figure, the converted multiple compressor or fan performance characteristic curves are extracted through the above process.

[0034] S5, extracting the working point characteristic parameters (pressure ratio, flow rate, efficiency), the surge point characteristic parameters (pressure ratio, flow rate, efficiency) and the surge margin of each compressor or fan performance characteristic curve;

[0035] S6, respectively establishing the curves of the working point characteristic parameters (pressure ratio, flow rate, efficiency), the surge point characteristic parameters (pressure ratio, flow rate, efficiency) and the surge margin with the change of the channel ratio or channel dimensionless back pressure, and fitting them into a model, wherein the fitting process adopts a quadratic relationship:

[0036] F = m(B) 2 +n(B)+p

[0037] In the formula, F is the characteristic parameter of the compression system, such as the working point characteristic (pressure ratio, flow rate, efficiency), the surge point characteristic (pressure ratio, flow rate, efficiency) or the surge margin; B is the channel ratio or channel dimensionless back pressure; m, n and p are coefficients, which vary with the test object and the speed state.

[0038] S7, analyze the rationality of the model, for example, the number of extracted characteristic lines can be increased to check the regular change of the model, and if it does not meet the analysis requirements, steps S2-S6 can be repeated.

[0039] The method of the present application can establish a model of the influence of the duct variable on the aerodynamic performance of the adaptive compression system based on the component test data, thereby quantitatively evaluating the change law of the performance parameters of the key states such as the compression system working point and surge with the characteristic variables such as the duct ratio, thereby effectively guiding the matching adjustment and use of the component under the condition of the aero-engine whole machine.

[0040] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for modeling the experimental matching characteristics of a variable cyclic compression system, characterized in that, include: A surface region feature map of aerodynamic performance of a variable cycle compression system is established. The horizontal axis of the surface region feature map is the converted flow rate of the variable cycle compression system, and the vertical axis is the characteristic parameters of the third duct of the adaptive three-duct fan or the front duct of the variable cycle compressor. The characteristic parameters are the bypass ratio or the dimensionless back pressure of the bypass. Key element curves were extracted from the surface feature map of the aerodynamic performance of the variable cycle compression system. Determine the bypass ratio or the dimensionless back pressure range of the bypass in the aerodynamic performance surface region feature map to be analyzed. Within the range of the bypass ratio or dimensionless back pressure of the bypass, extract several compressor or fan aerodynamic performance characteristic curves from the blockage point to the surge point when the bypass ratio or dimensionless back pressure of the bypass remains constant, under the condition of fixed characteristic parameters. Extract the operating point characteristic parameters, surge point characteristic parameters, and surge margin of each compressor or fan aerodynamic performance characteristic curve; The operating point characteristic parameters, surge point characteristic parameters, and surge margin are established as curves of variation with bypass ratio or dimensionless back pressure of bypass, and then fitted into a model to obtain the aerodynamic performance characteristic curves matching the variable cycle compression system.

2. The method for modeling the experimental matching characteristics of a variable cyclic compression system as described in claim 1, characterized in that, Key element curves include the operating line, the highest efficiency line or the highest pressure ratio line, and the surge boundary line.

3. The method for modeling the experimental matching characteristics of a variable cyclic compression system as described in claim 1, characterized in that, No fewer than four aerodynamic performance characteristic curves of the compressor or fan should be extracted.

4. The method for modeling the test matching characteristics of a variable cyclic compression system as described in claim 1, characterized in that, The operating point characteristic parameters and the surge point characteristic parameters include pressure ratio, flow rate, and efficiency.

5. The method for modeling the test matching characteristics of a variable cyclic compression system as described in claim 4, characterized in that, The fitting process uses a quadratic equation: F = m(B) 2 +n(B)+p In the formula, F is the operating point characteristic parameter, surge point characteristic parameter, or surge margin; B is the bypass ratio or dimensionless back pressure of the bypass; and m, n, and p are coefficients that vary with the test object and the rotational speed.

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