A method for measuring the throat height of a binary nozzle

Abstract

The application belongs to the field of aircraft engine nozzles, and particularly relates to a method for measuring the throat height of a two-dimensional nozzle. The method comprises the following steps: processing a scale line on the side wall of the nozzle; and reading the throat height h of the nozzle in real time through the scale line. The scale line is an arc segment with the intersection of the nozzle support shaft and the side wall of the nozzle as the center and the length of the converging section as the radius. The method for measuring the throat height of the two-dimensional nozzle greatly improves the measurement accuracy of the throat area of the nozzle, avoids errors caused by indirect measurement and measurement deviation caused by deformation of the heat shield, improves the operation safety, avoids climbing operation, saves the cost, eliminates the measurement tools and telescopic rods, shortens the working period, and completes the measurement work by directly reading the value.

Description

Technical Field

[0001] This application belongs to the field of aero-engine nozzles, and specifically relates to a method for measuring the throat height of a two-dimensional nozzle. Background Technology

[0002] The nozzle area has a significant impact on engine performance parameters such as intake airflow and low-pressure speed. Therefore, the nozzle area needs to be adjusted according to different conditions to match the appropriate nozzle area for different engine conditions. In order to obtain an accurate nozzle area, the nozzle area needs to be measured and calibrated before the test. Therefore, the rapid and accurate measurement of the nozzle area has become an important part of the test, which can affect not only engine performance but also engine safety.

[0003] The length L of the binary nozzle is a fixed value, while the height h is adjusted as the actuator extends and retracts. The nozzle area S = L × h. Before the test, the minimum and maximum nozzle throat heights need to be measured for the control software to perform fitting calculations, ensuring that the actual nozzle area equals the displayed value during the test. The throat height needs to be measured after each nozzle assembly or after a long period of stable operation. Completing this task takes 2 hours each time, greatly affecting the test efficiency.

[0004] The nozzle throat height includes the height of the heat shield from the load-bearing plate; therefore, the actual height = actual measured value + height of the upper and lower heat shields from the inner side of the load-bearing plate (see...). Figure 1 In existing technologies, a fixed telescopic rod is used for indirect height measurement (see...). Figure 2 After fixing, remove it and measure it with vernier calipers (see...). Figure 3 This method has the following drawbacks:

[0005] a) The use of telescopic rods for measurement is an indirect method, which greatly reduces the accuracy of the measurement;

[0006] b) This method requires manual climbing at heights, which carries significant risks;

[0007] c) The telescopic pole and measuring equipment need to be designed and manufactured separately, increasing costs;

[0008] d) The telescopic pole needs to be locked after it reaches a fixed height. Because of the need for climbing to work, it needs to be handed over to other staff to measure after locking, and multiple measurements are required to take the average value, which greatly consumes time and manpower costs.

[0009] e) The heat insulation screen is prone to bending and deformation after long-term operation. At this time, the height of the heat insulation screen from the inner side of the load-bearing plate changes. Using theoretical values ​​for calculation can lead to a large deviation between the measured value and the actual value.

[0010] Based on the above situation, there is an urgent need to design an efficient, safe, and accurate measurement method.

[0011] Therefore, it is desirable to have a technical solution to overcome or at least mitigate one of the aforementioned defects of the prior art. Summary of the Invention

[0012] The purpose of this application is to provide a method for measuring the throat height of a two-dimensional nozzle to solve at least one problem existing in the prior art.

[0013] The technical solution of this application is:

[0014] A method for measuring the throat height of a two-dimensional nozzle includes:

[0015] Machine graduation lines onto the sidewall of the nozzle;

[0016] The nozzle throat height h is read in real time using the scale lines.

[0017] In at least one embodiment of this application, the scale line is an arc segment with the intersection of the nozzle support shaft and the nozzle sidewall as the center and the length of the convergent segment as the radius.

[0018] In at least one embodiment of this application, the scale values ​​on the scale lines are determined in the following manner:

[0019] A rectangular coordinate system is constructed with the intersection of the nozzle support axis and the nozzle sidewall as the origin, the horizontal direction as the x-axis, and the vertical direction as the y-axis.

[0020] The equation of the scale line is:

[0021] x 2 +y 2 =r 2

[0022] Where r is the length of the nozzle convergence section;

[0023] The formula for calculating the nozzle throat height is:

[0024] h = 2(Hym)

[0025] Where h is the nozzle throat height, H is half the nozzle sidewall height, and m is the load-bearing plate thickness;

[0026] By measuring the y-value multiple times and substituting it into the formula for calculating the nozzle throat height, the scale value on the scale line is fitted.

[0027] The invention has at least the following beneficial technical effects:

[0028] The two-dimensional nozzle throat height measurement method of this application greatly improves the measurement accuracy of nozzle throat area, avoids errors caused by indirect measurement and measurement deviations caused by heat shield deformation; enhances operational safety and avoids working at height; saves costs and eliminates the need for measuring tools and telescopic poles; shortens the work cycle, and allows measurement work to be completed by intuitively reading the values. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of throat height measurement;

[0030] Figure 2 This is a schematic diagram of measuring throat height using a telescopic rod;

[0031] Figure 3 This is a schematic diagram of a telescopic rod.

[0032] Figure 4 This is a schematic diagram of the side wall scale lines according to one embodiment of this application;

[0033] Figure 5 This is a schematic diagram of a scale value fitting method according to one embodiment of this application. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0035] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this application.

[0036] The following is in conjunction with the appendix Figures 4 to 5 This application will be described in further detail.

[0037] This application provides a method for measuring the throat height of a two-dimensional nozzle, including the following steps:

[0038] Machine graduation lines onto the sidewall of the nozzle;

[0039] The nozzle throat height h is read in real time using the scale lines.

[0040] The method for measuring the throat height of a two-dimensional nozzle in this application involves creating scale lines during the machining of the nozzle sidewall. The scale lines should be clear and not affect the structural strength. The nozzle throat height h can be observed in real time after the nozzle is in operation.

[0041] like Figure 4 As shown, the two-dimensional nozzle includes a converging section and a diverging section. One end of the converging section is connected to the nozzle support shaft, and the other end is connected to the diverging section. Both the converging section and the diverging section are composed of upper and lower wall plates and two side wall plates. Each wall plate includes a load-bearing plate and a heat shield set inside the load-bearing plate. The nozzle throat is adjusted by controlling the extension and retraction of the upper and lower wall plates through the actuator.

[0042] The method for measuring the throat height of a two-dimensional nozzle in this application is based on the fact that the motion trajectory of the end connecting the converging section and the expanding section of the two-dimensional nozzle is an arc. The scale line is set according to the motion trajectory of the converging section of the nozzle. That is, the scale line is an arc segment with the intersection of the nozzle support axis and the nozzle sidewall as the center and the length of the converging section as the radius.

[0043] In this embodiment, the scale values ​​on the scale lines are determined in the following way:

[0044] A rectangular coordinate system is constructed with the intersection of the nozzle support axis and the nozzle sidewall as the origin, the horizontal direction as the x-axis, and the vertical direction as the y-axis.

[0045] The equation of the scale line is:

[0046] x 2 +y 2 =r 2

[0047] Where r is the length of the nozzle convergence section;

[0048] The formula for calculating the nozzle throat height is:

[0049] h = 2(Hym)

[0050] Where h is the nozzle throat height, H is half the nozzle sidewall height, and m is the load-bearing plate thickness;

[0051] By repeatedly and precisely measuring the y-value, and substituting it into the formula for calculating the nozzle throat height, the scale value on the scale line is fitted.

[0052] The method for measuring the throat height of a two-dimensional nozzle disclosed in this application can accurately and quickly measure the throat height of a two-dimensional nozzle. This application greatly improves operability and safety, reduces the number of operators by one, saves labor costs and measuring tool costs, shortens the measurement time to 12.5% ​​of the original time, and improves measurement accuracy.

[0053] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for measuring the throat height of a binary nozzle, characterized in that, include: Machine graduation lines onto the sidewall of the nozzle; The nozzle throat height h is read in real time using the scale lines. The scale line is an arc segment with the intersection of the nozzle support shaft and the nozzle sidewall as the center and the length of the convergent section as the radius; The scale values ​​on the scale lines are determined in the following manner: A rectangular coordinate system is constructed with the intersection of the nozzle support axis and the nozzle sidewall as the origin, the horizontal direction as the x-axis, and the vertical direction as the y-axis. The equation of the scale line is: x 2 +y 2 =r 2 ; Where r is the length of the nozzle convergence section; The formula for calculating the nozzle throat height is: h=2(Hym); Where h is the nozzle throat height, H is half the nozzle sidewall height, and m is the load-bearing plate thickness; By measuring the y-value multiple times and substituting it into the formula for calculating the nozzle throat height, the scale value on the scale line is fitted.

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