Aero-engine labyrinth clearance monitoring method

Abstract

The invention belongs to the field of aero-engines, and provides an aero-engine labyrinth gap monitoring method, which comprises the following steps: establishing a first relational expression between the key position temperature of a labyrinth rotor and the cavity temperature and a second relational expression between the key position temperature of a labyrinth stator and the cavity temperature through a simulation method and a test method; establishing a third relational expression among radial deformation of the labyrinth rotor, the rotating speed and the cavity temperature according to the designed rotating speed, the first relational expression and the second relational expression; establishing a fourth relational expression between radial deformation of the labyrinth stator and the cavity temperature by adopting a fitting method through the second relational expression; according to the labyrinth initial clearance, the third relational expression and the fourth relational expression, a fifth relational expression of the labyrinth clearance, the rotating speed and the cavity temperature in the working process of the engine is established; and the current rotating speed and the current cavity temperature of the engine are collected in real time, and the current labyrinth gap is calculated through a fifth relational expression. According to the method, the collision and abrasion risk position gap change can be monitored in real time in the test run process, and data support is provided for test operators.

Description

Technical Field

[0001] The invention belongs to the field of aviation engines, relates to a grate clearance monitoring technology in an air system, and particularly relates to a grate clearance monitoring method for an aviation engine. Background Art

[0002] The grate seal is the most commonly used non-contact sealing structure in modern aircraft engine air systems. It plays a very important role in cooling the engine's high-temperature components, regulating axial forces, and ensuring sealing. During the engine test, the rotor and stator undergo radial deformation due to the influence of engine speed and temperature, which causes the grate clearance to change. When the grate clearance deviates from the design value, on the one hand, it will lead to loss of control of the cooling effect, axial force regulation effect, and sealing effect. On the other hand, it may cause the rotor and stator to rub, which brings certain risks to engine testing. Currently, there is no method for real-time monitoring of the grate clearance during testing. The resulting rubbing can usually only be discovered after the engine is disassembled at the end of the test. Summary of the Invention

[0003] In order to solve the technical problem that during the test of an aircraft engine, due to the change of the grate clearance, the rotor and stator rub against each other, which brings risks to the test, the present invention discloses a method for monitoring the grate clearance of an aircraft engine, which comprises the following steps:

[0004] S1. Based on the temperature field obtained by the simulation method and the cavity temperature obtained by the test, the temperature field analysis and structural strength analysis are used to establish the first relationship between the temperature at the key position of the grate rotor and the cavity temperature, and the second relationship between the temperature at the key position of the grate stator and the cavity temperature;

[0005] S2. Based on the design speed corresponding to the typical operating condition and the first relationship, a third relationship between the radial deformation of the grate rotor and the speed and cavity temperature is established by a fitting method;

[0006] S3. Using the second relationship, a fitting method is used to establish a fourth relationship between the radial deformation of the grate stator and the cavity temperature;

[0007] S4. Establishing a fifth relationship between the grate clearance, the speed, and the chamber temperature during engine operation based on the initial grate clearance, the third relationship, and the fourth relationship.

[0008] S5. Collect the current engine speed and current cavity temperature in real time, and calculate the current grate tooth gap using the fifth relational expression.

[0009] Furthermore, in step S1, based on the temperature field obtained by the simulation method and the cavity temperature obtained by the experiment, a first relationship between the temperature at the key position of the grate rotor and the cavity temperature and a second relationship between the temperature at the key position of the grate stator and the cavity temperature are established by using temperature field analysis and structural strength analysis, including:

[0010] S11. Obtaining the grate rotor temperature field and the grate stator temperature field under multiple typical working conditions through a simulation method, and arranging thermocouples in the chamber to obtain the chamber temperature through experiments, wherein the chamber temperature includes the upstream chamber temperature and the downstream chamber temperature;

[0011] S12. Obtaining the key positions of the rotor and the stator through temperature field analysis and strength analysis based on the cavity temperature and temperature field;

[0012] S13. Calculate the average temperature of the grate rotor and the average temperature of the grate stator under all the typical working conditions, define the average temperature of the grate rotor as the key position temperature of the grate rotor, and define the average temperature of the grate stator as the key position temperature of the grate stator;

[0013] S14. Establish the first relationship and the second relationship by using a linear fitting regression method based on the cavity temperatures under multiple typical working conditions.

[0014] Furthermore, in step S14, the expression of the first relational equation is: T r =b1*TQ1+b2*TQ2+b3, the expression of the second relational formula is: T s =a1*TQ1+a2*TQ2+a3, where T r is the temperature at the key position of the grate rotor, T s is the temperature at the key position of the grate stator, TQ1 is the temperature of the upstream chamber, TQ2 is the temperature of the downstream chamber, a1, a2, a3, b1, b2, and b3 are all fitting coefficients.

[0015] Furthermore, in step S2, based on the design speed corresponding to the typical working condition and the first relationship, a third relationship between the radial deformation of the grate rotor and the cavity temperature is established by a fitting method, including:

[0016] S21. Calculate the centrifugal deformation of the grate rotor corresponding to the design speed under each typical operating condition by a simulation method, and use the design speeds and corresponding centrifugal deformations of the grate rotor under all the typical operating conditions to perform fitting to obtain an exponential function relationship between the centrifugal deformation of the grate rotor and the speed;

[0017] S22. Calculate the thermal expansion deformation of the grate rotor under each typical operating condition by a simulation method, and use all the thermal expansion deformations of the grate rotor and the first relationship to perform fitting to obtain a polynomial function relationship between the thermal expansion deformation of the grate rotor and the cavity temperature;

[0018] S23. Summing the exponential function relationship and the polynomial function relationship to obtain the third relationship.

[0019] Furthermore, in steps S21 to S23, the exponential function relationship is Δδr1 =c1*n c2 , the expression of the polynomial function relationship Δδ r2 =d1*(b1*TQ1+b2*TQ2+b3) 2 +d2*(b1*TQ1+b2*TQ2+b3)+d3, the expression of the third relational formula is Δδ r =Δδ r1 +Δδ r2 , where Δδ r is the radial deformation of the grate rotor, Δδ r1 is the centrifugal deformation of the grate rotor, Δδ r2 is the thermal expansion deformation of the grate rotor, TQ1 is the temperature of the upstream chamber, TQ2 is the temperature of the downstream chamber, n is the rotational speed, a1, a2, a3, b1, b2, b3, c1, c2, d1, d2, and d3 are all fitting coefficients.

[0020] Furthermore, in step S3, the expression of the fourth relational equation is Δδ s =e1*(a1*TQ1+a2*TQ2+a3), where Δδ s is the radial deformation of the grate stator, TQ1 is the temperature of the upstream chamber, TQ2 is the temperature of the downstream chamber, e1, a1, a2, and a3 are all fitting coefficients.

[0021] Furthermore, in step S4, the expression of the fifth relational equation is δ=δ0+e1*(a1*TQ1+a2*TQ2+a3)-c1*n c2 -(d1*(b1*TQ1+b2*TQ2+

[0022] b3) 2 +d2*(b1*TQ1+b2*TQ2+b3)+d3), where δ is the grate gap, TQ1 is the upstream chamber temperature, TQ2 is the downstream chamber temperature, δ0 is the initial grate gap, n is the rotational speed, and e1, a1, a2, a3, b1, b2, b3, c1, c2, d1, d2, and d3 are all fitting coefficients.

[0023] The present grate clearance monitoring method utilizes readily measurable engine speed and upstream and downstream grate cavity temperatures during engine testing to enable real-time monitoring of clearances at all engine locations prone to friction, improving safety during engine testing. Testers can adjust test parameters based on the clearance monitoring values to prevent test risks such as rotor-stator friction and high-temperature gas backflow. Simultaneously, the clearance monitoring values can be used to further verify simulation results, improving design accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. 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 any creative work.

[0025] Figure 1 The present invention is a flowchart of a method for monitoring the clearance of grate teeth of an aero-engine disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0027] The following describes the embodiments 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 embodiments, 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 features of the following embodiments and embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of this application.

[0028] During the engine test, the speed, upstream and downstream chamber temperatures are closely related to the grate clearance, which can be obtained through very mature testing methods. Therefore, the present invention establishes a method for real-time monitoring of the grate clearance of an aircraft engine based on the engine speed and upstream and downstream chamber temperatures. Figure 1 As shown, the method includes the following steps:

[0029] S1. Based on the temperature field obtained by the simulation method and the cavity temperature obtained by the test, the temperature field analysis and structural strength analysis are used to establish the first relationship between the temperature at the key position of the grate rotor and the cavity temperature, and the second relationship between the temperature at the key position of the grate stator and the cavity temperature;

[0030] S2. Based on the design speed corresponding to the typical operating condition and the first relationship, a third relationship between the radial deformation of the grate rotor and the speed and cavity temperature is established by a fitting method;

[0031] S3. Using the second relationship, a fitting method is used to establish a fourth relationship between the radial deformation of the grate stator and the cavity temperature;

[0032] S4. Establishing a fifth relationship between the grate clearance, the speed, and the chamber temperature during engine operation based on the initial grate clearance, the third relationship, and the fourth relationship.

[0033] S5. Collect the current engine speed and current cavity temperature in real time, and calculate the current grate tooth gap using the fifth relational expression.

[0034] Furthermore, in step S1, based on the temperature field obtained by the simulation method and the cavity temperature obtained by the experiment, a first relationship between the temperature at the key position of the grate rotor and the cavity temperature and a second relationship between the temperature at the key position of the grate stator and the cavity temperature are established by using temperature field analysis and structural strength analysis, including:

[0035] S11. Obtaining the grate rotor temperature field and the grate stator temperature field under multiple typical working conditions through a simulation method, and arranging thermocouples in the chamber to obtain the chamber temperature through experiments, wherein the chamber temperature includes the upstream chamber temperature and the downstream chamber temperature;

[0036] S12. Obtaining the key positions of the rotor and the stator through temperature field analysis and strength analysis based on the cavity temperature and temperature field;

[0037] S13. Calculate the average temperature of the grate rotor and the average temperature of the grate stator under all the typical working conditions, define the average temperature of the grate rotor as the key position temperature of the grate rotor, and define the average temperature of the grate stator as the key position temperature of the grate stator;

[0038] S14. Establish the first relationship and the second relationship by using a linear fitting regression method based on the cavity temperatures under multiple typical working conditions.

[0039] Furthermore, in step S14, the expression of the first relational equation is: T r =b1*TQ1+b2*TQ2+b3; the expression of the second relational expression is: T s =a1*TQ1+a2*TQ2+a3; where T r is the temperature of the key position of the rotor grate teeth, T s is the temperature at the key position of the grate stator, TQ1 is the temperature of the upstream chamber, TQ2 is the temperature of the downstream chamber, a1, a2, a3, b1, b2, and b3 are all fitting coefficients.

[0040] Furthermore, in step S2, based on the design speed corresponding to the typical working condition and the first relationship, a third relationship between the radial deformation of the grate rotor and the cavity temperature is established by a fitting method, including:

[0041] S21. Calculate the centrifugal deformation of the grate rotor corresponding to the design speed under each typical operating condition by a simulation method, and use the design speeds and corresponding centrifugal deformations of the grate rotor under all the typical operating conditions to perform fitting to obtain an exponential function relationship between the centrifugal deformation of the grate rotor and the speed;

[0042] S22. Calculate the thermal expansion deformation of the grate rotor under each typical operating condition by a simulation method, and use all the thermal expansion deformations of the grate rotor and the first relationship to perform fitting to obtain a polynomial function relationship between the thermal expansion deformation of the grate rotor and the cavity temperature;

[0043] S23. Summing the exponential function relationship and the polynomial function relationship to obtain the third relationship.

[0044] Furthermore, in steps S21 to S23, the exponential function relationship is Δδ r1 =c1*n c2 , the expression of the polynomial function relationship Δδ r2 =d1*(b1*TQ1+b2*TQ2+b3) 2 +d2*(b1*TQ1+b2*TQ2+b3)+d3, the expression of the third relational formula is Δδ r =Δδ r1 +Δδ r2 , where Δδ r is the radial deformation of the grate rotor, Δδ r1 is the centrifugal deformation of the grate rotor, Δδ r2 is the thermal expansion deformation of the grate rotor, TQ1 is the temperature of the upstream chamber, TQ2 is the temperature of the downstream chamber, n is the rotational speed, a1, a2, a3, b1, b2, b3, c1, c2, d1, d2, and d3 are all fitting coefficients.

[0045] Furthermore, in step S3, the expression of the fourth relational equation is Δδ s =e1*(a1*TQ1+a2*TQ2+a3), where Δδ s is the radial deformation of the grate stator, TQ1 is the temperature of the upstream chamber, TQ2 is the temperature of the downstream chamber, e1, a1, a2, and a3 are all fitting coefficients.

[0046] Furthermore, in step S4, the expression of the fifth relational equation is δ=δ0+e1*(a1*TQ1+a2*TQ2+a3)-c1*n c2 -(d1*(b1*TQ1+b2*TQ2+

[0047] b3) 2+d2*(b1*TQ1+b2*TQ2+b3)+d3), where δ is the grate gap, TQ1 is the upstream chamber temperature, TQ2 is the downstream chamber temperature, δ0 is the initial grate gap, n is the rotational speed, and e1, a1, a2, a3, b1, b2, b3, c1, c2, d1, d2, and d3 are all fitting coefficients.

[0048] The present grate clearance monitoring method utilizes readily measurable engine speed and upstream and downstream grate cavity temperatures during engine testing to enable real-time monitoring of clearances at all engine locations prone to friction, improving safety during engine testing. Testers can adjust test parameters based on the clearance monitoring values to prevent test risks such as rotor-stator friction and high-temperature gas backflow. Simultaneously, the clearance monitoring values can be used to further verify simulation results, improving design accuracy.

[0049] Obviously, those skilled in the art should understand that the various modules or steps of the above-mentioned embodiments of the present invention can be implemented using a general-purpose computing device, they can be concentrated on a single computing device, or distributed across a network composed of multiple computing devices. Alternatively, they can be implemented using program code executable by the computing device, so that they can be stored in a storage device and executed by the computing device. In some cases, the steps shown or described can be performed in a different order than herein, or they can be made into separate integrated circuit modules, or multiple modules or steps can be made into a single integrated circuit module for implementation. Thus, the embodiments of the present invention are not limited to any specific combination of hardware and software.

[0050] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for monitoring the clearance of grate teeth of an aircraft engine, characterized in that: include: Based on the temperature field obtained by simulation and the cavity temperature obtained by experiment, the first relationship between the temperature at the key position of the grate rotor and the cavity temperature and the second relationship between the temperature at the key position of the grate stator and the cavity temperature are established by temperature field analysis and structural strength analysis. According to the design speed corresponding to the typical operating condition and the first relationship, a third relationship between the radial deformation of the grate rotor and the speed and cavity temperature is established by a fitting method; Based on the second relational expression, a fitting method is used to establish a fourth relational expression between the radial deformation of the grate stator and the cavity temperature; According to the initial grate clearance, the third relational expression, and the fourth relational expression, a fifth relational expression is established for the grate clearance, the rotational speed, and the cavity temperature during engine operation; The current speed and current cavity temperature of the engine are collected in real time, and the current grate tooth gap is calculated using the fifth relational expression.

2. The method for monitoring the clearance of the grate teeth of an aircraft engine according to claim 1, characterized in that: Based on the temperature field obtained by simulation and the cavity temperature obtained by experiment, the first relationship between the temperature at the key position of the grate rotor and the cavity temperature and the second relationship between the temperature at the key position of the grate stator and the cavity temperature are established by temperature field analysis and structural strength analysis, including: The temperature fields of the grate rotor and the grate stator under multiple typical working conditions are obtained by simulation methods, and the cavity temperature is obtained by experiments by placing thermocouples in the cavity, which includes the cavity temperature of the upstream cavity and the cavity temperature of the downstream cavity; According to the cavity temperature and temperature field, the key positions of the rotor and stator are obtained through temperature field analysis and strength analysis; Calculating the average temperature of the grate rotor and the average temperature of the grate stator under all the typical working conditions respectively, defining the average temperature of the grate rotor as the key position temperature of the grate rotor, and defining the average temperature of the grate stator as the key position temperature of the grate stator; The first relationship and the second relationship are established by using a linear fitting regression method based on the cavity temperatures under multiple typical working conditions.

3. The method for monitoring the clearance of the grate teeth of an aircraft engine according to claim 2, characterized in that: The expression of the first relational formula is: r =b1*TQ1+b2*TQ2+b3, the expression of the second relational formula is: T s =a1*TQ1+a2*TQ2+a3; where T r is the temperature at the key position of the grate rotor, T s is the temperature at the key position of the grate stator, TQ1 is the temperature of the upstream chamber, TQ2 is the temperature of the downstream chamber, a1, a2, a3, b1, b2, and b3 are all fitting coefficients.

4. The method for monitoring the clearance of the grate teeth of an aircraft engine according to claim 1, characterized in that: According to the design speed corresponding to the typical working condition and the first relationship, a third relationship between the radial deformation of the grate rotor and the cavity temperature is established by a fitting method, including: The centrifugal deformation of the grate rotor corresponding to the design speed under each typical working condition is calculated by simulation method. The design speed and the corresponding centrifugal deformation of the grate rotor under all the typical working conditions are used to fit the exponential function relationship between the centrifugal deformation of the grate rotor and the speed; Calculating the thermal expansion deformation of the grate rotor under each typical working condition by a simulation method, and using all the thermal expansion deformations of the grate rotor and the first relationship to perform fitting to obtain a polynomial function relationship between the thermal expansion deformation of the grate rotor and the cavity temperature; The exponential function relationship expression and the polynomial function relationship expression are summed to obtain the third relationship expression.

5. The method for monitoring the clearance of the grate teeth of an aircraft engine according to claim 4, characterized in that: The exponential function relationship is Δδ r1 =c1*n c2 , the expression of the polynomial function relationship Δδ r2 =d1*(b1*TQ1+b2*TQ2+b3) 2 +d2*(b1*TQ1+b2*TQ2+b3)+d3, the expression of the third relational formula is Δδ r =Δδ r1 +Δδ r2 , where Δδ r is the radial deformation of the grate rotor, Δδ r1 is the centrifugal deformation of the grate rotor, Δδ r2 is the thermal expansion deformation of the grate rotor, TQ1 is the temperature of the upstream chamber, TQ2 is the temperature of the downstream chamber, n is the rotational speed, a1, a2, a3, b1, b2, b3, c1, c2, d1, d2, and d3 are all fitting coefficients.

6. The method for monitoring the clearance of the grate teeth of an aircraft engine according to claim 1, characterized in that: The expression of the fourth relational equation is Δδ s =e1*(a1*TQ1+a2*TQ2+a3), where Δδ s is the radial deformation of the grate stator, TQ1 is the temperature of the upstream chamber, TQ2 is the temperature of the downstream chamber, e1, a1, a2, and a3 are all fitting coefficients.

7. The method for monitoring the clearance of the grate teeth of an aircraft engine according to claim 1, characterized in that: The fifth relational expression is: δ=δ0+e1*(a1*TQ1+a2*TQ2+a3)-c1*n c2 -(d1*(b1*TQ1+b2*TQ2+b3) 2 +d2*(b1*TQ1+b2*TQ2+b3)+d3), where δ is the grate gap, TQ1 is the upstream chamber temperature, TQ2 is the downstream chamber temperature, δ0 is the initial grate gap, n is the rotational speed, and e1, a1, a2, a3, b1, b2, b3, c1, c2, d1, d2, and d3 are all fitting coefficients.

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