Multi-stage axial flow compressor stage flow coefficient design method based on inter-stage test data

Abstract

The invention provides a multi-stage axial flow compressor stage flow coefficient design method based on inter-stage test data. The method comprises the following steps that firstly, compressor stages and experimental test parameters are defined; 2, according to the outer wall static pressure # imgabs0 # measured in the step 1, the stator front average static pressure P is calculated; 3, according to the total pressure, measured in the step 1, of the multiple measuring points, the stator front average total pressure # imgabs1 # is calculated; 4, according to the total temperature, measured in the step 1, of the multiple measuring points, the stator front average total temperature # imgabs2 # is calculated; step 5, determining a stator inlet and outlet axial speed correction coefficient # imgabs3 #; and step 6, determining a stage flow coefficient # imgabs4 # according to the step 2 to the step 5. According to the method, on the basis of the aerodynamic basic equation, the capacity of carrying out compressor interstage parameter matching analysis on the basis of interstage test data can be remarkably improved through the reasonable hypothesis and curve fitting conforming to the compressor aerodynamic basic principle.

Description

Technical Field

[0001] The invention relates to the technical field of aerodynamic design of multi-stage axial flow compressors, and in particular to a method for designing stage flow coefficients of multi-stage axial flow compressors based on inter-stage test data. Background Art

[0002] Good inter-stage parameter matching is an important factor in determining the performance of multi-stage fans / compressors (hereinafter referred to as compressors). In order to further analyze the inter-stage parameter matching of compressors in engineering design, the matching between the stages of multi-stage compressors is analyzed by conducting inter-stage tests and test data analysis, which is an indispensable part of the independent research and development of modern aircraft engine compressors. However, due to the limitations of test conditions, in most cases, the inter-stage measurement of multi-stage compressors can only measure the total temperature, total pressure, and outer wall static pressure in front of each stator.

[0003] The dimensionless coefficient important for compressor stage matching analysis, namely, stage flow coefficient (this coefficient characterizes the flow capacity of the stage and is the coefficient for judging the flow matching of each stage), cannot be directly calculated through stage test data. As a result, the value of previous multi-stage compressor stage test data has not been fully utilized. Summary of the invention

[0004] In view of this, the present invention provides a method for designing a multi-stage axial flow compressor stage flow coefficient based on inter-stage test data, so as to achieve the purpose of improving the ability to carry out compressor inter-stage parameter matching analysis based on inter-stage test data.

[0005] The present invention provides the following technical solution: a method for designing the flow coefficient of a multi-stage axial flow compressor stage based on inter-stage test data, comprising the following steps: step 1, defining the compressor stage and test parameters; step 2, determining the flow coefficient of a multi-stage axial flow compressor stage based on the inter-stage test data; step 3, determining the flow coefficient of a multi-stage axial flow compressor stage based on the inter-stage test data; step 4, determining the flow coefficient of a multi-stage axial flow compressor stage based on the inter-stage test data; step 5, determining the flow coefficient of a multi-stage axial flow compressor stage based on the inter-stage test data; step 6, determining the flow coefficient of a multi-stage axial flow compressor stage based on the inter-stage test data; step 7, determining the flow coefficient of a multi-stage axial flow compressor stage based on the inter-stage test data; step 8, determining the flow coefficient of a multi-stage axial flow compressor stage based on the inter-stage test data; step 9, determining the flow coefficient of a multi-stage , calculate the average static pressure P in front of the stator; Step 3, calculate the average total pressure in front of the stator according to the total pressure of multiple measuring points measured in step 1 ; Step 4: Calculate the average total temperature before the stator based on the total temperature of multiple measuring points measured in step 1 ; Step 5: Determine the stator inlet and outlet axial velocity correction coefficient ; Step 6: Determine the stage flow coefficient according to steps 2 to 5 .

[0006] Furthermore, through the formula Calculate the average static pressure P in front of the stator.

[0007] Furthermore, through the formula Calculate the average total pressure before the stator , where P1-Pn is the total pressure measured at the n total pressure measuring points in front of the stator, S is the annular area of ​​the entire blade, , … It is the annular area between two measuring points or between a measuring point and the inner and outer walls.

[0008] Furthermore, through the formula Calculate the average total temperature before the stator , where T1-Tn is the total temperature measured by the first n total temperature measurement points of the stator.

[0009] Furthermore, through the formula , determine the stator inlet and outlet axial velocity correction coefficient ,in, is the stator inlet annular area, is the annular area of ​​the stator outlet.

[0010] Furthermore, through the formula Determine the stage flow coefficient , where R is the gas constant; A is the annular area in front of the stage stator, in units of ; is the tangential velocity at the middle of the rotor blade, in units , k is the adiabatic index.

[0011] Furthermore, through the stage flow coefficient Compare with the design target value to determine whether the flow capacity of the multi-stage axial flow compressor reaches the design target.

[0012] Compared with the prior art, the beneficial effects achieved by at least one of the above technical solutions adopted by the present invention include at least the following: Based on the basic aerodynamic equations, the present invention proposes a method for calculating the stage flow coefficient of a multi-stage axial flow compressor based on inter-stage test data through reasonable assumptions and curve fitting that conform to the basic principles of compressor aerodynamics. The ability to carry out compressor inter-stage parameter matching analysis based on inter-stage test data can be significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 It is a schematic diagram of the process of the present invention; Figure 2 The definition of compressor stage and the schematic diagram of measuring point distribution; Figure 3 The flow coefficient calculation process for the compressor stage; Figure 4 This is a schematic diagram of the total pressure measurement point in front of the compressor stator; Figure 5 This is a schematic diagram of the total temperature measurement point in front of the compressor stator; Figure 6 This is a schematic diagram of the definition of the second stage of a compressor and the distribution of test measurement points. DETAILED DESCRIPTION

[0015] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0016] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0017] like Figure 1 As shown, the present invention provides a method for designing a multi-stage axial flow compressor stage flow coefficient based on inter-stage test data, which specifically includes the following steps: 1. Define compressor stages and test parameters; Since the interstage total temperature and total pressure measurement points can only be arranged on the stator blades in the test, it is necessary to redefine the compressor stages, such as Figure 2 As shown in the figure, one stage of the compressor consists of a row of "stator + rotor" blades. The total temperature and total pressure measurement point is the circular point in the figure, in front of the stator blades, and the outer wall static pressure measurement point is the star point in the figure, on the outer wall casing of the compressor.

[0018] 2. Define the calculation method of compressor stage flow coefficient; The calculation process of compressor stage flow coefficient is as follows: Figure 3 As shown. The calculation formula designed in the figure is as follows: (1) (2) (3) (4) (5) Formulas (1)-(3) are the basic aerodynamic equations, formula (4) is the correction formula for calculating the rotor inlet axial speed based on the stator inlet axial speed, and formula (5) is the calculation formula for the stage flow coefficient.

[0019] The parameters in the formula are defined as follows: Table 1 Specific meaning of each parameter

[0020] In formula (1) to formula (5), the most critical parameter for solving the flow coefficient is: , , , Four parameters, these four parameters need to be given according to test data fitting or design experience, other parameters: the air flow m in front of the stage stator can be directly measured through experiments, the annular area A in front of the stage stator can be calculated after the compressor design is determined, and the tangential speed in the middle of the rotor blade R and Usually it is a constant. Therefore, the key to calculating the flow coefficient is to accurately give: , , , The values ​​of the four parameters.

[0021] 3. Calculate the average static pressure before the stator ; Average static pressure before the stage stator The determination of the static pressure of the outer wall measured in the test 1 is required Based on the correction: (6) In formula 6, The static pressure on the front outer wall of the stage stator measured in the test.

[0022] 4. Calculate the average total pressure before the stator ; mean total pressure in front of stator The calculation of is based on the area-weighted average of the total pressure at n radial points measured in the test, such as Figure 4 The calculation method is as follows: (7) In formula 7, P1-Pn is the total pressure measured at the n total pressure measuring points in front of the stator, S is the annular area of ​​the entire blade, , … It is the annular area between two measuring points or between a measuring point and the inner and outer walls.

[0023] 5. Calculate the average total temperature before the stator ; mean total pressure in front of stator The calculation of is based on the area-weighted average of the total pressure at n radial points measured in the test, such as Figure 5 The calculation method is as follows: (8) In formula 8, T1-Tn is the total temperature measured by the first n total temperature measurement points of the stator, S is the annular area of ​​the entire blade, , … It is the annular area between two measuring points or between a measuring point and the inner and outer walls.

[0024] 6. Determine the axial velocity correction coefficient at the stator inlet and outlet ; Axial speed correction factor The calculation formula is related to the ratio of the annular area of ​​the compressor stator inlet and outlet flow passages, and the calculation formula is as follows: (9) In formula (9) is the stator inlet annular area, is the annular area of ​​the stator outlet.

[0025] 7. Calculation of flow coefficient ; Substituting the four key parameters obtained from the above calculation into formula (1)-formula (5), the stage flow coefficient can be calculated. .

[0026] The following is a further detailed explanation using the second stage of a multi-stage axial flow compressor as an example: 1. Define the second stage of the compressor and test parameters like Figure 6 As shown, the combination of the first-stage stator and the second-stage rotor of the compressor is defined as the "second stage", and the inter-stage measuring points are the total temperature and total pressure at 5 radial points in front of the first-stage stator, and the static pressure of the outer wall in front of the first-stage stator.

[0027] 2. Define the calculation method of compressor stage flow coefficient Determine the basic equation for calculating the streamline coefficient.

[0028] 3. Calculate the average static pressure before the stator

[0029] Calculate the average static pressure in front of the first stage stator , calculated .

[0030] 4. Calculate the average total pressure before the stator

[0031] Calculate the average total pressure before the first stage stator , calculated .

[0032] 5. Calculate the average total temperature before the stator

[0033] Calculate the average total temperature before the first stage stator according to the method described in step 5 of the invention content. , calculated .

[0034] 6. Determine the axial velocity correction coefficient at the stator inlet and outlet

[0035] Calculate the axial velocity correction factor at the inlet and outlet of the first stage stator , calculated

[0036] 7. Calculation of flow coefficient

[0037] The four key parameters calculated are put into formula (1)-formula (5) to calculate the stage flow coefficient .

[0038] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for designing the stage flow coefficient of a multi-stage axial flow compressor based on inter-stage test data, characterized in that: The following steps are involved: Step 1: Define the compressor stage and test parameters; Step 2: According to the outer wall static pressure measured in step 1 , calculate the average static pressure P in front of the stator; Step 3: Calculate the average total pressure before the stator based on the total pressure of multiple measuring points measured in step 1 ; Step 4: Calculate the average total temperature before the stator according to the total temperature of multiple measuring points measured in step 1. ; Step 5: Determine the axial velocity correction coefficient at the stator inlet and outlet ; Step 6: Determine the stage flow coefficient according to steps 2 to 5 .

2. The method for designing the stage flow coefficient of a multi-stage axial flow compressor based on inter-stage test data according to claim 1, characterized in that: By formula Calculate the average static pressure P in front of the stator.

3. The method for designing the stage flow coefficient of a multi-stage axial flow compressor based on inter-stage test data according to claim 2, characterized in that: By formula Calculate the average total pressure before the stator , where P1-Pn is the total pressure measured at the n total pressure measuring points in front of the stator, S is the annular area of ​​the entire blade, , … It is the annular area between two measuring points or between a measuring point and the inner and outer walls.

4. The method for designing the stage flow coefficient of a multi-stage axial flow compressor based on inter-stage test data according to claim 3 is characterized in that: By formula Calculate the average total temperature before the stator , where T1-Tn is the total temperature measured by the first n total temperature measurement points of the stator.

5. The method for designing the stage flow coefficient of a multi-stage axial flow compressor based on inter-stage test data according to claim 4 is characterized in that: By formula , determine the stator inlet and outlet axial velocity correction coefficient ,in, is the stator inlet annular area, is the annular area of ​​the stator outlet.

6. The method for designing the stage flow coefficient of a multi-stage axial flow compressor based on inter-stage test data according to claim 4, characterized in that: By formula Determine the stage flow coefficient , where R is the gas constant; A is the annular area in front of the stage stator, in units of ; is the tangential velocity at the middle of the rotor blade, in units , k is the adiabatic index.

7. The method for designing the stage flow coefficient of a multi-stage axial flow compressor based on inter-stage test data according to claim 6, characterized in that: Through-stage flow coefficient Compare with the design target value to determine whether the flow capacity of the multi-stage axial flow compressor reaches the design target.

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