A foreign matter damage pre-preparation system and pre-preparation method in a blade rotating state

Abstract

The application provides a foreign object damage pre-preparation system and method in a blade rotating state, the system comprising: a tester cavity, in a vacuum state during a test; a motor for driving the tester to rotate; a driving shaft connecting the motor and a test piece mounting disc; the test piece mounting disc for bearing a blade test piece, the blade test piece being mounted on the edge of the test piece mounting disc; a counterweight mounted on the test piece mounting disc for a counterweight sensor for the blade test piece, the sensor extending into the tester cavity for measuring the rotating speed of the blade test piece; a controller connecting the motor, the sensor and a projectile launcher, the projectile launcher comprising a barrel, and a projectile being mounted in the barrel. The controller controls the projectile projection trigger time, so that the projectile freely falls down and hits the leading edge position of the blade requiring foreign object damage pre-preparation, thereby realizing foreign object damage pre-preparation.

Description

Technical Field

[0001] The present application belongs to the field of aero-engine technology, and in particular relates to a foreign object damage prefabrication system and a prefabrication method for blades in a rotating state. Background Art

[0002] During aircraft engine operation, especially during takeoff and landing, aircraft equipped with these engines inevitably ingest small hard foreign objects such as sand, gravel, and small metal pieces. During this ingestion process, these small hard objects can collide with the engine's fan / compressor blades, causing damage to the blades. This damage caused by small hard foreign objects is called "Foreign Object Damage" (FOD). Damage to fan / compressor blades caused by small hard foreign objects is generally not immediately detected, and they must continue to operate for a period of time until the damage is detected and addressed. During this period, the blades must not break, which would affect engine safety. In other words, fan / compressor blades must be able to operate safely for a period of time after sustaining FOD damage, referred to as FOD resistance. GJB241A-2010 requires that engine fan / compressor blades must possess a certain level of FOD resistance. After FOD damage occurs, the blades must be able to continue operating safely for a certain period of time according to specified procedures, provided that the blade pre-fabrication stress concentration factor (Kt) is not less than 3.0. It is also stipulated that before the engine is finalized and put into production, the test verification of the blade's ability to resist foreign object damage must be completed, which is called the foreign object damage test. The test requires the pre-fabrication of foreign object damage notches with a Kt of not less than 3.0 on three fan / compressor blades, and the whole machine hanging test or component test is carried out on the damaged blades to verify the safety over a period of time.

[0003] One of the most crucial aspects of engine FOD testing is the prefabrication of FOD notches with a Kt of no less than 3.0 on the three fan / compressor blades. Current methods for prefabricating FOD notches include the air cannon method, pendulum method, quasi-static method, and machining method. The notches created by the pendulum, quasi-static, and machining methods differ significantly from actual impact damage and cannot simulate the complex surface conditions of actual FOD. While the air cannon method can simulate actual FOD to a certain extent, the blades remain stationary during the test, whereas during actual FOD, the blades rotate at high speeds. This creates significant prestress in the damaged area, and the material properties of the impacted area differ from those in a stationary state due to strain rate effects. Because the air cannon method cannot simulate the actual high-speed rotation of the blades, the FOD notches created using the air cannon method still differ from the actual situation. Moreover, the impact energy of the prefabricated foreign object damage during the test by the air cannon method mainly comes from the kinetic energy of the projectile fired by the air cannon, and the morphology of the prefabricated notch also depends on the speed and direction of the projectile. Due to the dispersion of the speed and direction of the projectile fired by the air cannon, the prefabricated foreign object damage notch is highly dispersed and has poor controllability. Summary of the Invention

[0004] The purpose of the present application is to provide a system and method for prefabricating foreign object damage in a rotating blade state, so as to solve or alleviate at least one problem in the background technology.

[0005] In one aspect, the present application provides a foreign object damage pre-processing system for blades in a rotating state, the system comprising:

[0006] A test chamber, wherein the test chamber is in a vacuum state during the test;

[0007] A motor, wherein the motor is used to drive the tester to rotate;

[0008] a drive shaft connected to the motor and the test piece mounting plate;

[0009] A test piece mounting plate, used for carrying a blade test piece, wherein the blade test piece is mounted on an edge of the test piece mounting plate;

[0010] The counterweight is installed on the test piece mounting plate and is used to balance the blade test piece.

[0011] a sensor extending into the tester cavity and configured to measure a rotational speed of the blade test piece;

[0012] a controller connected to the motor, the sensor, and the projectile launcher, wherein the projectile launcher includes a barrel in which the projectile is installed;

[0013] The distance between the projectile and the prefabricated position of damage on the leading edge of the blade is H, the circumferential angle between the sensor and the barrel is θ, and the rotation speed of the test piece is W.

[0014] On the other hand, the present application provides a method for prefabricating the above-mentioned foreign object damage prefabrication system under a rotating blade state, the prefabrication method comprising:

[0015] The motor drives the test piece mounting plate to rotate, accelerating the rotation speed of the blade test piece to the working speed W and keeping it stable;

[0016] The projectile is allowed to fall freely and hit the leading edge of the blade test piece, where the FOD traces need to be preformed. The following conditions must be met to preform the FOD traces:

[0017]

[0018] Where t1 is the time consumed in the sensor signal transmission and triggering process;

[0019] t is the projectile launch trigger time;

[0020] H is the distance between the initial position of the projectile and the target impact front edge;

[0021] g is the acceleration due to gravity;

[0022] θ is the circumferential angle between the sensor and the barrel;

[0023] [] is the rounding function.

[0024] In the prefabrication system and prefabrication method provided by the present application, the blade test piece is in a high-speed rotating state. By controlling the rotation speed to be the same as the actual working speed, the prestress of the blade and the strain rate effect during impact can be simulated, and high-fidelity foreign object damage can be prefabricated. The present application accurately controls the speed and direction of the projectile through free fall and the barrel, accurately controls the projectile projection time through the sensor, accurately controls the blade rotation speed through the motor, and accurately controls the impact angle and speed of the projectile and the blade through coordinated calculation, thereby achieving precise control of the impact process and reducing the dispersion of foreign object damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] 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.

[0026] Figure 1 Schematic diagram of the foreign object damage prefabrication system for blades in rotating state according to the present application.

[0027] Figure 2 This is a top view of the foreign object damage prefabrication system of the present application when the blade is in a rotating state. 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] To address the issue of prefabricated FOD, ensuring that the surface state of the FOD is consistent with the actual FOD, and to address the issue of blade state during FOD prefabrication, enabling simulation of the prestress state and strain rate state of the blade during the actual FOD process, and to address the dispersion issue during prefabrication, improve controllability, and minimize dispersion of the prefabricated FOD gap, the present application provides a method for prefabricating FOD on a fan compressor blade of an aircraft engine while the blade is rotating.

[0030] like Figure 1 and Figure 2As shown, first, the present application provides a system for prefabricating foreign object damage to fan or compressor blades in a rotating blade state. The system comprises: a test chamber 1, a motor 2, a drive shaft 3, a test piece mounting plate 4, a counterweight 6, a sensor 7, a controller 8, and a projectile launcher. During the test, the test chamber 1 is in a vacuum state. The motor 2 is connected to the test piece mounting plate 4 via the drive shaft 3, thereby driving the test piece mounting plate 4 to rotate. The test piece mounting plate 4 is used to support the blade test piece. The blade test piece 5 is mounted on one edge of the test piece mounting plate 4. A counterweight 6 is mounted on the other side of the test piece mounting plate 4 to offset the rotational effect of the blade test piece 5 on the test piece mounting plate 6. The sensor 7 extends into the test chamber 1 and measures the rotational speed of the blade test piece 5. The projectile launcher includes a barrel 9, within which a projectile 10 is mounted. The controller 8 is connected to the motor 2, sensor 7, and projectile launcher and is used to control the motor to stop rotation, obtain and process measurement data from the sensor 7, and control the projectile launcher to launch the projectile 10. Among them, in this prefabrication system, the distance between the projectile 10 and the damage prefabrication position of the blade leading edge is H, the circumferential angle between the sensor and the barrel is θ, and the rotation speed of the test piece is W.

[0031] The prefabrication process of foreign object damage on blades is as follows:

[0032] 1) Control the motor 2 to drive the rotating shaft 3 to rotate, and the rotating shaft 3 in turn drives the test piece mounting plate 4 to rotate, thereby accelerating the rotation speed of the blade test piece 5 to the working speed W and maintaining it stable;

[0033] 2) The controller 8 controls the triggering time of the projectile 10 so that the projectile 10 falls freely and hits the leading edge of the blade where foreign object damage is required. The relationship between them is as follows:

[0034]

[0035] Where, the circumferential angle between the sensor and the barrel is θ, the distance between the initial position of the projectile and the target impact edge is H, the gravitational acceleration is g, the time consumed in the sensor signal transmission and triggering process is t1, the projectile launch trigger time is t, [] is the rounding function, the speed unit is r / min, the time unit is s, and the angle unit is °.

[0036] In the prefabrication system and prefabrication method provided by the present application, the blade test piece is in a high-speed rotating state. By controlling the rotation speed to be the same as the actual working speed, the prestress of the blade and the strain rate effect during impact can be simulated, and high-fidelity foreign object damage can be prefabricated. The present application accurately controls the speed and direction of the projectile through free fall and the barrel, accurately controls the projectile projection time through the sensor, accurately controls the blade rotation speed through the motor, and accurately controls the impact angle and speed of the projectile and the blade through coordinated calculation, thereby achieving precise control of the impact process and reducing the dispersion of foreign object damage.

[0037] 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 method for prefabricating foreign object damage using a foreign object damage prefabrication system in a rotating blade state, characterized in that: The system comprises: A test chamber (1), wherein the test chamber (1) is in a vacuum state during the test; A motor (2), the motor (2) being used to drive the tester to rotate; A drive shaft (3), the drive shaft (3) being connected to the motor (2) and the test piece mounting plate (4); A test piece mounting plate (4) is used to carry a blade test piece (5), wherein the blade test piece (5) is mounted on an edge of the test piece mounting plate (4); A counterweight (6) is mounted on the test piece mounting plate (4) and is used to counterweight the blade test piece (5). A sensor (7), the sensor (7) extending into the tester cavity (1) and used for measuring the rotational speed of the blade test piece (5); A controller (8), wherein the controller (8) is connected to the motor (2), the sensor (7) and the projectile launcher, wherein the projectile launcher includes a barrel (9) and a projectile (10) is installed in the barrel (9); The prefabrication method comprises: The test piece mounting plate (4) is driven to rotate by the motor (2), and the rotation speed of the blade test piece (5) is accelerated to a working rotation speed W and kept stable; The projectile (10) is made to fall freely and hit the leading edge of the blade test piece (5) where foreign object damage needs to be preformed, and the following conditions are met, thereby preforming foreign object damage marks: Where t1 is the time consumed in the sensor signal transmission and triggering process; t is the projectile launch trigger time; H is the distance between the initial position of the projectile and the target impact front edge; g is the acceleration due to gravity; θ is the circumferential angle between the sensor and the barrel; [] is the rounding function; H is the distance between the projectile (10) and the damage prefabrication position of the blade leading edge; θ is the circumferential angle between the sensor (7) and the gun barrel (9); W is the rotation speed of the test piece.

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