Aero-engine transition state blade tip clearance calculation method and device

Abstract

The invention provides an aero-engine transition state blade tip clearance calculation method, and belongs to the technical field of aero-engines, and the method comprises the following steps: carrying out overall performance parameter calculation, compressor and turbine part performance parameter calculation, air system internal flow parameter calculation and rotor and stator structural member temperature field calculation in sequence, blade tip gaps are input in part performance parameter calculation and air system internal flow parameter calculation; according to the influence of the centrifugal load and the thermal load, rotor and stator structural part deformation calculation is carried out, and a rotor and stator structural part radial deformation calculation result is obtained; according to a calculation result of the radial deformation of the rotor and stator structural component, calculating a rotor and stator blade tip clearance value by combining the factors having influence on the blade tip clearance; and judging whether the obtained rotor and stator blade tip clearance value meets the requirement or not, if not, assigning the obtained rotor and stator blade tip clearance value to the blade tip clearance calculated by the single step length in the transition state, and repeating the process until the obtained rotor and stator blade tip clearance value meets the requirement.

Description

Technical Field

[0001] This application belongs to the technical field of aeroengines, and particularly relates to a method and device for calculating the tip clearance of an aeroengine during the transient state. Background Art

[0002] For an aeroengine, the tip clearance of the compressor and turbine components is an important design parameter. The size of the tip clearance during the transient state will directly affect the performance, reliability, and economy of the aeroengine. Therefore, in order to promote the improvement and replacement of the overall working quality of aeroengines, the requirements for engine performance are getting higher and higher, and thus the requirements for the accuracy of tip clearance calculation and prediction are also getting higher and higher.

[0003] As Figure 1 shown, the process of the existing method for calculating the tip clearance during the transient state of an aeroengine is as follows:

[0004] Step S1: First, perform the calculation of overall performance parameters and output the calculation results of parameters such as temperature, pressure, and flow rate at each cross-section of the main flow path;

[0005] Step S2: Perform the calculation of the performance parameters of the compressor and turbine components and output the calculation results of parameters such as temperature and pressure at each stage cross-section. At this time, the tip clearance is a constant within a single step during the transient state calculation;

[0006] Step S3: Perform the calculation of the internal flow parameters of the air system and output the calculation results of parameters such as temperature and pressure in each cavity on the flow path. At this time, the seal clearance is a constant within a single step during the transient state calculation;

[0007] Step S4: Perform the calculation of the temperature field of the rotating and stationary structural components and output the calculation result of the transient temperature field of the rotating and stationary components;

[0008] Step S5: Perform the calculation of the deformation of the rotating and stationary components considering the influence of centrifugal load and thermal load and output the calculation result of the radial deformation amount of the rotating and stationary structural components;

[0009] Step S6: Consider the initial clearance in the assembled state and calculate the tip clearance between the rotating and stationary components, and output the calculation result of the tip clearance during the transient state.

[0010] The existing method for calculating the tip clearance has the following disadvantages:

[0011] 1) The tip and seal clearance values used in the transient state calculations of component performance in Step S2 and air system parameters in Step S3 are constants, which have an error compared with the clearance result calculated in Step S6. An excessive error will lead to relatively large calculation results of component performance and air system parameters, and the error will be passed on layer by layer downstream, causing a loss of accuracy in the final clearance calculation result;

[0012] 2) In step S6, the calculation of the stator-rotor clearance in the transition state only considers the initial clearance in the assembled state, lacking the influence of the deformation of the whole machine's stator-rotor on the circumferential non-uniformity of the tip clearance, which affects the calculation accuracy. Summary of the Invention

[0013] The purpose of this application is to provide a method for calculating the tip clearance of an aero-engine in the transition state to solve or mitigate at least one problem in the background art.

[0014] The technical solution of this application is: a method for calculating the tip clearance of an aero-engine in the transition state, including:

[0015] Step S10, carry out the calculation of overall performance parameters to obtain the parameter calculation results of each cross-section of the main flow path;

[0016] Step S20, carry out the calculation of component performance parameters of the compressor and turbine to obtain the parameter calculation results of each stage cross-section of the components. Among them, during the calculation of component performance parameters, the tip clearance in the first calculation of a single step in the transition state uses the given initial value as the input, and the iterative calculation of the tip clearance uses the clearance value calculated in step S60 as the input;

[0017] Step S30, carry out the calculation of internal flow parameters of the air system to obtain the parameter calculation results of each cavity on the flow path. Among them, during the calculation of internal flow parameters of the air system, the tip clearance in the first calculation of a single step in the transition state uses the given initial value as the input, and the iterative calculation of the tip clearance uses the clearance value calculated in step S60 as the input;

[0018] Step S40, carry out the calculation of the temperature field of the stator-rotor structural parts to obtain the calculation results of the stator-rotor transition state temperature;

[0019] Step S50, carry out the deformation calculation of the stator-rotor structural parts according to the influence of centrifugal load and thermal load to obtain the calculation results of the radial deformation of the stator-rotor structural parts;

[0020] Step S60, according to the calculation results of the radial deformation of the stator-rotor structural parts, calculate the stator-rotor tip clearance value in combination with the factors that affect the tip clearance;

[0021] Step S70, judge whether the stator-rotor tip clearance value obtained in step S60 meets the requirements. If it does not meet the requirements, assign the stator-rotor tip clearance value obtained in step S60 to the tip clearance calculated in a single step of the transition state in step S20 and / or step S30, and repeat the above process until the stator-rotor tip clearance value obtained in step S60 meets the requirements.

[0022] In an alternative embodiment of this application, the parameter calculation results of each cross-section of the main flow path include the temperature, pressure, and flow rate of each cross-section.

[0023] In an alternative embodiment of the present application, the calculation results of the cross-sectional parameters at all levels of the component include the temperature and pressure at all levels of the cross-section.

[0024] In an alternative embodiment of the present application, the parameters of each cavity in the flow path include the temperature and pressure of each cavity.

[0025] In an alternative embodiment of the present application, the factors affecting the tip clearance include the initial clearance in the assembled state, the coaxiality of the fulcrum, the change in bearing clearance during operation, the thermal bending of the rotor, and the flexural deformation of the stator and rotor.

[0026] In an alternative embodiment of the present application, in step S70, the method for determining whether the tip clearance value of the stator and rotor obtained in step S60 meets the requirements is as follows:

[0027] Calculate the difference between the tip clearance value input in step S20 or step S30 and the tip clearance value obtained in step S60;

[0028] Determine whether the difference exceeds the threshold value. If it does not exceed the threshold value, it meets the requirements; if it exceeds the threshold value, it does not meet the requirements.

[0029] In an alternative embodiment of the present application, the threshold value does not exceed 5%.

[0030] The method for calculating the tip clearance in the transition state provided by the present application performs closed-loop iterative calculations, enabling dynamic interaction between the calculation of the tip clearance value, the component performance, and the air system calculation within the step size. This reduces the transmission of calculation errors downstream, ensures the calculation accuracy of the deformation of the blades, casings, and disks, and improves the calculation accuracy of the circumferential distribution of the tip clearance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions provided by the present application, the drawings will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application.

[0032] Figure 1 It is a schematic flow chart of a prior art method for calculating tip clearance.

[0033] Figure 2 It is a schematic flow chart of the method for calculating the tip clearance in the transition state of an aero-engine according to the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] To make the objectives, technical solutions, and advantages of the implementation of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the drawings in the embodiments of the present application.

[0035] To solve the problem that the calculation of component performance and air system in the prior art uses constant clearances, resulting in inaccurate calculation of tip clearance, and the problem that the calculation of stator-rotor clearance does not consider the influencing factors of the overall engine deformation, this application provides a method for calculating the tip clearance of an aero-engine during the transient state.

[0036] As Figure 2 shown, the method for calculating the tip clearance of an aero-engine during the transient state provided by this application includes the following processes:

[0037] Step S10: Conduct the calculation of overall performance parameters to obtain the calculation results of parameters such as temperature, pressure, and flow rate at each cross-section of the main flow path;

[0038] Step S20: Conduct the calculation of performance parameters of the compressor and turbine components to obtain the calculation results of parameters such as temperature and pressure at each stage cross-section. Among them, during the calculation of component performance, the initial value t0 is used as the input for the first calculation of the tip clearance in a single step of the transient state, and the clearance value t1 calculated in step S60 is used as the input for subsequent calculations of the tip clearance;

[0039] Step S30: Conduct the calculation of internal flow parameters of the air system to obtain the calculation results of parameters such as temperature and pressure in each cavity on the flow path. Among them, during the calculation of internal flow parameters of the air system, the initial value t0 is used as the input for the first calculation of the sealing clearance in a single step of the transient state, and the clearance value t1 calculated in step S60 is used as the input for subsequent calculations of the sealing clearance;

[0040] Step S40: Conduct the calculation of the temperature field of the stator-rotor structural components to obtain the calculation result of the transient temperature field of the stator-rotor;

[0041] Step S50: Consider the influence of centrifugal load and thermal load to conduct the deformation calculation of the stator-rotor structural components to obtain the calculation result of the radial deformation of the stator-rotor structural components;

[0042] Step S60: On the basis of the calculation result of step S50, superimpose the factors that affect the tip clearance to calculate the tip clearance between the stator and the rotor to obtain the clearance value t1;

[0043] In this application, the above factors that affect the tip clearance include the initial clearance in the assembled state, the coaxiality of the fulcrum, the change in bearing clearance during operation, the thermal bending of the rotor, the flexural deformation of the stator-rotor, etc.

[0044] Step S70: Determine whether the transitional tip clearance value obtained in step S60 meets the requirements. If it meets the requirements, the final transitional tip clearance is obtained. If it does not meet the requirements, the clearance value t1 obtained in step S60 is returned to step S20 and / or step S30 to recalculate the component performance parameters or the internal flow parameters of the air system, and the transitional tip clearance calculation process from step S40 to step S60 is executed again until the transitional tip clearance value obtained in step S60 meets the requirements.

[0045] In this application, by determining whether the difference between the tip clearance value input in step S20 or step S30 and the tip clearance value obtained in step S60 exceeds a threshold, it is determined whether the transitional tip clearance value obtained in step S60 meets the requirements. If it does not exceed the threshold, it meets the requirements; if it exceeds the threshold, it does not meet the requirements and recalculation is performed. In a preferred embodiment of this application, the above threshold generally does not exceed 5%.

[0046] It should be noted that the overall performance parameter calculation, component performance parameter calculation, internal flow parameter calculation of the air system, temperature field calculation of the stator and rotor structural components, etc. in the above steps of this application can all adopt the methods in the prior art and will not be elaborated here. Among them, the calculation results of the previous step are usually used for the calculation of the next step, that is, the overall performance parameter calculation results can be used for the component performance parameter calculation, the component performance parameter calculation results can be used for the internal flow parameter calculation of the air system, and the internal flow parameter calculation of the air system can be used for the temperature field calculation of the stator and rotor structural components, etc.

[0047] The transitional tip clearance calculation method provided by this application performs closed-loop iterative calculation, enabling dynamic interaction between the tip clearance value calculation and the component performance and air system calculations within the step size, reducing the downward transmission of calculation errors; the parameters output by the component performance calculation are generated under the condition that the tip clearance error is not greater than the threshold, ensuring the calculation accuracy of blade and casing deformation; the parameters output by the air system parameter calculation are generated under the condition that the seal clearance error is not greater than the threshold, ensuring the calculation accuracy of disk deformation; in addition to axisymmetric factors such as centrifugal force and thermal load, the calculated clearance value includes the influence of non-axisymmetric factors such as assembly clearance, bearing clearance, fulcrum coaxiality, rotor thermal bending, and stator-rotor flexural deformation under the overall conditions, improving the calculation accuracy of the circumferential distribution of the tip clearance.

[0048] The above is only the specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in this application should be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

1. A method for calculating the transient state tip clearance of an aeroengine, characterized in that: include: Step S10, performing overall performance parameter calculation to obtain parameter calculation results of each cross section of the main channel; Step S20, calculating the performance parameters of the compressor and turbine components, and obtaining the calculation results of the cross-sectional parameters of the components at all levels, wherein in the process of calculating the performance parameters of the components, the first calculation of the tip clearance in a single step of the transition state uses the given initial value as input, and the iterative calculation of the tip clearance uses the clearance value calculated in step S60 as input; Step S30, calculating the flow parameters in the air system to obtain the calculation process of the parameters of each cavity on the flow path, wherein, in the process of calculating the flow parameters in the air system, the first calculation of the blade tip clearance in a single step of the transition state uses the given initial value as input, and the iterative calculation of the blade tip clearance uses the clearance value calculated in step S60 as input; Step S40, performing temperature field calculation of rotor-stator structural parts to obtain calculation results of rotor-stator transition state temperature; Step S50, performing deformation calculation of the rotor-stator structural components according to the influence of the centrifugal load and the thermal load, and obtaining the calculation result of the radial deformation of the rotor-stator structural components; Step S60, calculating the rotor-stator blade tip clearance value according to the calculation result of the radial deformation of the rotor-stator structure and the factors that have an impact on the blade tip clearance; Step S70, determine whether the rotor-stator blade tip clearance value obtained in step S60 meets the requirements. If not, assign the rotor-stator blade tip clearance value obtained in step S60 to the blade tip clearance calculated by the single step length of the transition state in step S20 and / or step S30, and repeat the above process until the rotor-stator blade tip clearance value obtained in step S60 meets the requirements.

2. The method for calculating the transient state tip clearance of an aircraft engine according to claim 1, characterized in that: The parameter calculation results of each cross section of the main channel include the temperature, pressure and flow rate of each cross section.

3. The method for calculating the transient blade tip clearance of an aircraft engine according to claim 1, characterized in that: The calculation results of the cross-sectional parameters of each level of the component include the temperature and pressure of each level of the cross-sectional parameters.

4. The method for calculating the transient blade tip clearance of an aircraft engine according to claim 1, characterized in that: The parameters of each cavity on the flow path include the temperature and pressure of each cavity.

5. The method for calculating the transient blade tip clearance of an aircraft engine according to any one of claims 1 to 4, characterized in that: The factors that affect the tip clearance include the initial clearance in the assembly state, the coaxiality of the support point, the change of the bearing clearance during the working process, the thermal bending of the rotor, and the flexural deformation of the rotor and stator.

6. The method for calculating the transient blade tip clearance of an aircraft engine according to claim 5, characterized in that: In step S70, the method for determining whether the rotor-stator blade tip clearance value obtained in step S60 meets the requirement is: Calculating the difference between the blade tip clearance value input in step S20 or step S30 and the blade tip clearance value obtained in step S60; It is determined whether the difference exceeds a threshold value. If the difference does not exceed the threshold value, the requirement is met; otherwise, the requirement is not met.

7. The method for calculating the transient blade tip clearance of an aircraft engine according to claim 6, characterized in that: The threshold does not exceed 5%.

Images