An experimental method for constructing the performance field characteristics of a variable cycle compression system

Abstract

The present application provides an experimental method for constructing the performance domain characteristics of a variable-cycle compression system, including: determining the range of characteristic parameters of the characteristic duct of the variable-cycle compression system that needs to be covered in the aerodynamic performance domain characteristic diagram; determining the key elements of the aerodynamic performance domain characteristics of the variable-cycle compression system to obtain the key element characteristic line; determining a number of aerodynamic performance characteristic curves that need to be recorded for the performance state of the experimental variable-cycle compression system, so that the collected aerodynamic performance characteristic points are evenly distributed in the aerodynamic performance domain characteristic diagram, and the key element characteristic line covers at least a number of experimental collection points; changing the state of the variable-cycle compression system from a blockage point to a breath point by simultaneously adjusting the exhaust throttling device of the non-characteristic duct, fixing or adjusting the exhaust throttling device of the characteristic duct, and recording the performance state of the variable-cycle compression system; processing the experimentally measured performance of the variable-cycle compression system by adopting the domain interpolation method to construct the performance domain characteristic diagram of the variable-cycle compression system.

Description

Technical Field

[0001] The present application belongs to the field of variable cycle compressor technology, and in particular relates to a test method for constructing performance domain characteristics of a variable cycle compression system. Background Art

[0002] Adaptive variable-cycle engines operate in multiple modes and have complex characteristics. Their compression components include a three-duct adaptive fan and a variable-cycle dual-duct compressor. To accommodate the engine's diverse operating modes, the compression system and components of these engines undergo significant aerodynamic and structural changes compared to conventional fans and compressors.

[0003] like Figure 1 The schematic diagram of a typical adaptive three-duct fan shown in the figure shows that the adaptive three-duct fan 10 includes adjustable blades 11, a fan front rotor 12, a fan front stator 13, a fan rear rotor 14 and a fan rear stator 16 in sequence. There is a pipe between the fan front stator 13 and the fan rear rotor 14, which forms a third duct 19. A diverter ring 17 is arranged behind the fan rear stator 14. The diverter ring 17 divides the fan main flow channel 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 double duct compressor is shown. The variable cycle double duct compressor 20 includes adjustable blades 21, a core engine driven fan rotor 22, a core engine driven fan stator 23, a compressor rotor 24 and a compressor stator 25 in sequence. There is a pipe between the core engine driven fan stator 23 and the compressor rotor 24, which forms a front duct 27. The rear side of the compressor stator 25 is the compressor outlet 26, forming a rear duct.

[0005] In an adaptive three-duct fan, the flow rate in the third duct between the front and rear fans is adjustable. Changes in the aerodynamic parameters (bypass ratio or dimensionless static pressure ratio) of the third duct have a significant impact on fan performance. Similarly, the aerodynamic parameters of the front duct of a variable cycle double-duct compressor also significantly affect its performance.

[0006] To better characterize the impact of changes in the aerodynamic parameters of the third duct of an adaptive three-duct fan or the front duct of a variable-cycle dual-duct compressor on the performance of the compression system, a performance surface characterization method that associates the characteristic parameters of the third duct / front duct with flow-pressure ratio or flow efficiency characteristics is used. This can better achieve aerodynamic characteristics under the influence of multi-parameter coupling and achieve a quantitative assessment of the impact of third duct / front duct environmental variables on fan / compressor performance. However, the workload of completing the experimental measurement of this performance surface is relatively large, so a test method that can efficiently construct performance surface characteristics is needed. Summary of the Invention

[0007] The purpose of this application is to provide an experimental method for constructing performance domain characteristics of a variable cycle compression system to solve or alleviate at least one problem in the background technology.

[0008] The technical solution of this application is: a test method for constructing performance domain characteristics of a variable cycle compression system, comprising:

[0009] Determining a range of characteristic parameters of the characteristic duct of the variable cycle compression system that needs to be covered in an aerodynamic performance surface area characteristic diagram, wherein the abscissa of the aerodynamic performance surface area characteristic diagram is the converted flow rate of the variable cycle compression system, and the ordinate is the characteristic parameter of the characteristic duct of the variable cycle compression system, and the characteristic parameter is the bypass ratio or the dimensionless back pressure;

[0010] Determining key elements of aerodynamic performance domain characteristics of the variable cycle compression system and obtaining key element characteristic lines corresponding to the key elements;

[0011] Determine the number of aerodynamic performance characteristic curves required to capture the performance state of the variable cycle compression system under test, ensure that the collected aerodynamic performance characteristic points are evenly distributed in the aerodynamic performance surface characteristic diagram, and ensure that the characteristic lines of the key elements of concern cover at least several test collection points;

[0012] By simultaneously adjusting the exhaust throttling device of the non-characteristic duct of the variable cycle compression system to change the state of the variable cycle compression system from the blocking point to the breathing point, and fixing or adjusting the exhaust throttling device of the characteristic duct of the variable cycle compression system, it is ultimately ensured that the characteristics admitted by the test cover the measurement requirements of the performance state scheme of the variable cycle compression system;

[0013] The variable cycle compression system performance measured in the experiment is processed by using the surface interpolation method to construct the surface characteristic map of the variable cycle compression system performance.

[0014] Furthermore, the characteristic duct is the third duct of an adaptive three-duct fan or the front duct of a variable cycle double-duct compressor.

[0015] Furthermore, the key element characteristic lines are the working line, the maximum efficiency line / maximum pressure ratio line, and the surge boundary line.

[0016] Furthermore, the number of aerodynamic performance characteristic curves recorded is no less than 4.

[0017] Furthermore, no less than 4 test collection points are covered on the key element characteristic line.

[0018] Furthermore, when the variable cycle compression system is an adaptive three-duct fan, the state of the adaptive three-duct fan is changed from the blockage point to the breath point by simultaneously adjusting the inner exhaust throttling device of the inner duct and the outer exhaust throttling device of the outer duct at the outlet of the adaptive three-duct fan, and the third duct exhaust throttling device is fixed or appropriately adjusted to ultimately ensure that the characteristics admitted by the test cover the measurement requirements of the adaptive three-duct fan performance status scheme.

[0019] Furthermore, when the variable cycle compression system is a variable cycle double-duct compressor, the state of the variable cycle double-duct compressor is changed from the blockage point to the breath point by adjusting the variable cycle double-duct compressor outlet exhaust throttling device, and the front duct exhaust throttling device is fixed or appropriately adjusted, ultimately ensuring that the characteristics admitted by the test cover the measurement requirements of the variable cycle double-duct compressor performance state plan.

[0020] Furthermore, the interpolation method used includes linear interpolation or piecewise cubic interpolation.

[0021] The method of the present application focuses on fitting the key elements in the domain characteristic diagram of the adaptive three-duct fan or the variable cycle dual-duct compressor. Combined with the interpolation algorithm, only 4 to 5 characteristic lines are required to complete the test admission of the domain characteristic diagram, which can significantly reduce the workload of the test admission characteristic lines and ensure good test accuracy. This can significantly improve the test efficiency of constructing the domain characteristic diagram of the aerodynamic performance of the adaptive variable cycle compression system (fan or compressor). Compared with the method of fixing the environmental variables of the third duct or the front duct to carry out test state control, the exhaust throttling device of the third duct or the front duct in the method of the present application is rarely adjusted, and there is no need to strictly ensure that the environmental variables of the third duct or the front duct are a certain fixed value. The difficulty of control is greatly reduced, the time consumed is significantly reduced, and the test efficiency can be improved by 2 to 3 times. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions provided by this application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application.

[0023] Figure 1 This is a schematic diagram of a typical adaptive three-duct fan structure.

[0024] Figure 2 This is a schematic diagram of a typical variable cycle double-duct compressor structure.

[0025] Figure 3 This is a schematic diagram of the aerodynamic performance surface characteristics of the variable cycle compression system in one embodiment of the present application.

[0026] Figure 4 Schematic diagram of the layout of an adaptive three-duct fan throttling device in one embodiment of the present application.

[0027] Figure 5 This is a schematic diagram of the arrangement of the throttling device of a variable cycle double-duct compressor in one embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below in conjunction with the drawings in the embodiments of this application.

[0029] like Figure 3 Shown is a schematic diagram of the aerodynamic performance surface characteristics of the variable cycle compression component provided in this embodiment of the present application. In this schematic diagram, the horizontal axis is the converted flow rate of the compression component, and the vertical axis is the bypass ratio or dimensionless duct back pressure of the third duct or the front duct.

[0030] When testing the performance of an adaptive variable-cycle compression system, if the test state is controlled by fixing the characteristic parameters of the third or front duct, the control of the aerodynamic environment (back pressure or flow) of the third or front duct usually requires an airflow injection or suction unit to control the fan or compressor state. This adjustment process is very cumbersome, and the test takes a long time to complete. This makes it very difficult to construct the characteristic through testing. For example, in a conventional fan or compressor performance test, it takes approximately 10 minutes to record 10 aerodynamic state points for one characteristic line. However, in an adaptive fan or variable-cycle compressor performance test, the control of the aerodynamic environment of the third or front duct at each state point requires an additional 1-2 minutes. Therefore, it takes approximately 20-30 minutes to complete the recording of one characteristic line. If a characteristic domain is constructed to record 5-8 characteristic lines, it takes 100-240 minutes. Furthermore, the prolonged high speed performance test poses a significant risk to the safe operation of the equipment.

[0031] In order to overcome the above problems, the present application provides a test method for constructing the performance domain characteristics of a variable cycle compression system, which includes the following steps:

[0032] S1. Determine the range of bypass ratio or dimensionless back pressure that needs to be covered for the third or front duct of an adaptive three-duct fan or variable cycle two-duct compressor test.

[0033] like Figure 3 The figure shows the aerodynamic performance domain 30 of the variable cycle compression component to be constructed. Before constructing the characteristic diagram of the aerodynamic performance domain, it is necessary to determine the range S that the bypass ratio or dimensionless back pressure of the third duct or the front duct needs to cover.

[0034] S2. Determine the key elements of the aerodynamic performance domain characteristics of the adaptive three-ducted fan or variable cycle double-ducted compressor, and obtain the key element characteristic lines - the working line 31, the maximum efficiency line / maximum pressure ratio line 32 and the surge boundary line 33, such as Figure 3 shown.

[0035] S3. Determine the performance status of the adaptive three-duct fan or variable cycle double-duct compressor under test. This performance status usually requires the acquisition of 4 to 5 aerodynamic performance characteristic curves, and ensure that the collected aerodynamic performance characteristic points are distributed as evenly as possible in the surface characteristics. At the same time, ensure that the characteristic lines of the key elements of concern (working line, maximum efficiency line / maximum pressure ratio line, surge boundary line) cover at least 4 test collection points.

[0036] like Figure 3 As shown, the recorded aerodynamic performance characteristic curve 34 is a fan test performance curve recorded by fixing the third ducted exhaust throttling device in a certain state and adjusting the first and second ducted exhaust throttling devices at the same time, and the recorded aerodynamic performance characteristic curve 35 is a fan test performance curve recorded by appropriately adjusting the third ducted exhaust throttling device in a certain state and adjusting the first and second ducted exhaust throttling devices at the same time.

[0037] S4. When testing the aerodynamic performance characteristic curve of the adaptive three-ducted fan, if Figure 4 As shown, an inner exhaust throttling device 102 and an outer exhaust throttling device 103 are respectively provided at the outlet of the inner duct 16 and the outer duct 18 of the adaptive three-duct fan, and a third duct exhaust throttling device 101 is provided at the outlet of the third duct 19. By simultaneously adjusting the inner exhaust throttling device 102 and the outer exhaust throttling device 103 of the inner duct 16 and the outer duct 18 of the adaptive three-duct fan outlet, the state of the adaptive three-duct fan is changed from the blocking point to the breathing point, and the third duct exhaust throttling device 101 is fixed or appropriately adjusted to ultimately ensure that the characteristics admitted by the test cover the measurement requirements of the fan performance status scheme.

[0038] S5. When testing the aerodynamic performance characteristic curve of a variable cycle double duct compressor, if Figure 5 As shown, an outlet exhaust throttling device 202 is provided at the outlet 26 of the variable cycle double duct compressor, and a front duct exhaust throttling device 201 is provided at the outlet of the front duct 27. The state of the compressor is changed from the blocking point to the breathing point by adjusting the outlet exhaust throttling device 202 of the variable cycle double duct compressor, and the front duct exhaust throttling device 201 is fixed or appropriately adjusted, ultimately ensuring that the characteristics admitted by the test cover the measurement requirements of the compressor performance state program.

[0039] S6. Process the measured aerodynamic performance of the adaptive three-ducted fan or variable cycle dual-ducted compressor using a surface interpolation method to construct a surface characteristic map of the adaptive fan or variable cycle compressor. The interpolation method may be linear interpolation or piecewise cubic (Hermite) interpolation.

[0040] The method of the present application focuses on fitting the key elements in the domain characteristic diagram of the adaptive three-duct fan or the variable cycle dual-duct compressor. Combined with the interpolation algorithm, only 4 to 5 characteristic lines are required to complete the test admission of the domain characteristic diagram, which can significantly reduce the workload of the test admission characteristic lines and ensure good test accuracy. This can significantly improve the test efficiency of constructing the domain characteristic diagram of the aerodynamic performance of the adaptive variable cycle compression system (fan or compressor). Compared with the method of fixing the environmental variables of the third duct or the front duct to carry out test state control, the exhaust throttling device of the third duct or the front duct in the method of the present application is rarely adjusted, and there is no need to strictly ensure that the environmental variables of the third duct or the front duct are a certain fixed value. The difficulty of control is greatly reduced, the time consumed is significantly reduced, and the test efficiency can be improved by 2 to 3 times.

[0041] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A test method for constructing performance domain characteristics of a variable cycle compression system, characterized in that: include: Determine the range of characteristic parameters of the characteristic duct of the variable cycle compression system that needs to be covered by the aerodynamic performance surface area characteristic diagram, wherein the characteristic duct is the third duct of an adaptive three-duct fan or the front duct of a variable cycle dual-duct compressor, the abscissa of the aerodynamic performance surface area characteristic diagram is the converted flow rate of the variable cycle compression system, and the ordinate is the characteristic parameter of the characteristic duct of the variable cycle compression system, and the characteristic parameter is the bypass ratio or dimensionless back pressure; Determining key elements of aerodynamic performance domain characteristics of the variable cycle compression system and obtaining key element characteristic lines corresponding to the key elements; Determine the number of aerodynamic performance characteristic curves required to capture the performance state of the variable cycle compression system being tested, wherein the number of aerodynamic performance characteristic curves is no less than four, ensure that the captured aerodynamic performance characteristic points are evenly distributed on the aerodynamic performance domain characteristic diagram, and ensure that at least a number of test acquisition points are covered on the characteristic line of the key elements of interest, wherein no less than four test acquisition points are covered on the characteristic line of the key elements of interest; By simultaneously adjusting the exhaust throttling device of the non-characteristic duct of the variable cycle compression system to change the state of the variable cycle compression system from the blocking point to the breathing point, and fixing or adjusting the exhaust throttling device of the characteristic duct of the variable cycle compression system, it is ultimately ensured that the characteristics admitted by the test cover the measurement requirements of the performance state scheme of the variable cycle compression system; The variable cycle compression system performance measured in the experiment is processed by using the surface interpolation method to construct the surface characteristic map of the variable cycle compression system performance.

2. The test method for constructing the performance domain characteristics of a variable cycle compression system according to claim 1, characterized in that: The key element characteristic lines are the working line, the maximum efficiency line / maximum pressure ratio line, and the surge boundary line.

3. The test method for constructing the performance domain characteristics of a variable cycle compression system according to claim 2, characterized in that: When the variable cycle compression system is an adaptive three-duct fan, the state of the adaptive three-duct fan is changed from the blockage point to the breath point by simultaneously adjusting the inner exhaust throttling device of the inner duct and the outer exhaust throttling device of the outer duct at the outlet of the adaptive three-duct fan, and the third duct exhaust throttling device is fixed or appropriately adjusted to ultimately ensure that the characteristics admitted by the test cover the measurement requirements of the adaptive three-duct fan performance status scheme.

4. The test method for constructing the performance domain characteristics of a variable cycle compression system according to claim 2, characterized in that: When the variable cycle compression system is a variable cycle double-duct compressor, the state of the variable cycle double-duct compressor is changed from the blockage point to the breath point by adjusting the variable cycle double-duct compressor outlet exhaust throttling device, and the front duct exhaust throttling device is fixed or appropriately adjusted to ultimately ensure that the characteristics admitted by the test cover the measurement requirements of the variable cycle double-duct compressor performance status plan.

5. The test method for constructing the performance domain characteristics of a variable cycle compression system according to claim 1, characterized in that: The interpolation methods used include linear interpolation or piecewise cubic interpolation.

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