A test device and method for measuring the load of an aircraft APU inlet system damper

Abstract

This invention proposes a test apparatus and method for measuring the damper load of an aircraft APU intake system, belonging to the field of aerodynamics technology. The aim is to solve the problem that existing technologies cannot provide comprehensive and reliable test data, thus failing to meet the engineering requirements for precise design and optimization of APU intake systems. In this invention, a vacuum tank, an external ejector pipe, a flow meter, and an internal ejector pipe are connected sequentially. A large plate is installed on one side of the wind tunnel test section, and the damper frame is installed in the mounting opening of the large plate and connected to one end of the air collection chamber pipe. The intake damper is hinged to the damper frame via an intake damper pivot, and the other end of the air collection chamber is connected to the internal ejector pipe. A rod-type balance is installed on the intake damper and the large plate, and a balance line is installed on the rod-type balance, which is connected to a dynamic measurement system. This invention solves the problem that existing technologies cannot provide comprehensive and reliable test data, thus failing to meet the engineering requirements for precise design and optimization of APU intake systems.

Description

Technical Field

[0001] This invention belongs to the field of aerodynamics technology, and in particular relates to a test device and method for measuring the damper load of an aircraft APU intake system. Background Technology

[0002] The APU (Air Processing Unit) intake system is a core component of the aircraft. Its function is to guide external airflow into the APU compressor, providing the necessary airflow for the APU under various operating conditions. As a key control component of the intake system, the intake damper must withstand significant aerodynamic loads when open on the ground and in the air, and the magnitude of the load increases significantly with increasing flight speed and opening angle.

[0003] Therefore, APU system design must use accurate damper loads as input to ensure that the damper and actuator have sufficient structural strength and reliability. If the aerodynamic load on the damper cannot be accurately assessed, it is difficult to determine the structural design input for the APU system damper, which may lead to an increase in structural mass or an underestimation of the load value, increasing flight risks during actual flight.

[0004] However, existing testing techniques lack specific load measurement test methods for APU inlet dampers, and current evaluations mainly rely on numerical simulation. This single approach cannot fully reproduce the load distribution and dynamic characteristics under complex flow fields, and cannot provide comprehensive test data support for the design and optimization of aircraft APU inlet systems, thus restricting the design accuracy and performance improvement of APU inlet systems.

[0005] In summary, there is an urgent need to design a test device and method for measuring the damper load of an aircraft APU intake system, in order to solve the problem that existing technologies cannot provide comprehensive and reliable test data and cannot meet the engineering requirements for precise design and optimization of the APU intake system. Summary of the Invention

[0006] A brief overview of the invention is given below to provide a basic understanding of certain aspects of it. It should be understood that this overview is not an exhaustive summary of the invention. It is not intended to identify key or essential parts of the invention, nor is it intended to limit the scope of the invention. Its purpose is merely to present certain concepts in a simplified form as a prelude to the more detailed description that follows.

[0007] In view of this, in order to solve the problem that existing technologies cannot provide comprehensive and reliable test data and cannot meet the engineering requirements for precise design and optimization of APU intake systems, this invention provides a test device and method for measuring the damper load of an aircraft APU intake system.

[0008] Option 1: A test device for measuring the damper load of an aircraft APU intake system, comprising a test piece, a wind tunnel test section, a vacuum ejection system, and a measurement system;

[0009] The vacuum ejection system includes a vacuum tank, an external ejection pipeline, a flow meter, and an internal ejection pipeline; the vacuum tank, the external ejection pipeline, the flow meter, and the internal ejection pipeline are connected in sequence.

[0010] The test piece includes a gas collection chamber, a damper frame, a large plate, an air intake damper, and an air intake damper shaft. The large plate has an installation port. One side of the large plate is installed in the wind tunnel test section. The damper frame is installed in the installation port of the large plate and connected to one end of the gas collection chamber pipeline. The air intake damper is hinged to the damper frame through the air intake damper shaft. The other end of the gas collection chamber is connected to the ejector pipeline inside the tunnel.

[0011] The measurement system includes a dynamic measurement system, a bar balance, and a balance line; the bar balance is installed on the air intake damper and a large flat plate, and a balance line is installed on the bar balance, which is connected to the dynamic measurement system.

[0012] Furthermore, the lever balance includes a lower ear seat, a positive threaded rod, a balance body, a negative threaded rod, and an upper ear seat; the lower ear seat is mounted on a large flat plate, the upper ear seat is mounted on an air intake damper, both the negative threaded rod and the positive threaded rod are provided with internal threads, and are connected to the upper ear seat and the lower ear seat respectively through hinge pins, and the balance body is provided with external threads at both ends to be threadedly connected to the negative threaded rod and the positive threaded rod.

[0013] Furthermore, both the reverse threaded rod and the forward threaded rod have threaded holes on their side walls, and the set screw is screwed into the threaded hole.

[0014] Option 2: A test method for measuring the damper load of an aircraft APU intake system, which is based on the test device for measuring the damper load of an aircraft APU intake system described in Option 1, and specifically includes the following steps:

[0015] S1. Install the test equipment in the wind tunnel test section: Set up a dynamic measurement system according to the test requirements, and after the setting is completed, conduct joint debugging of the entire system;

[0016] S2. Adjust the intake damper to open it to the required opening for the test: Adjust the opening of the intake damper according to the test conditions by adjusting the length of the lever balance. Use a digital inclinometer to measure the opening of the intake damper. After the opening is adjusted, lock the positive thread rod and the negative thread rod with the set screw.

[0017] S3. Start the wind tunnel and activate the vacuum ejection system: Control and measure the flow rate of the APU intake system through the flow meter. During the test, a vacuum ejection test with no incoming flow is first required to determine the cone position of the flow meter to achieve the required flow rate. During the formal wind tunnel test, the cone position of the flow meter is directly moved to that position, and the flow rate is measured at the same time.

[0018] S4. Acquiring Damper Load: When the internal and external flow fields are stable and the flow rate in the pipeline of the APU intake system reaches the test requirements, the real-time load of the rod balance is acquired using a dynamic measurement system to obtain the time-domain curve of the intake damper load. After obtaining the time-domain curve of the load, according to the definition of torque, the load is multiplied by the distance from the point of action of the rod balance to the intake damper shaft to obtain the torque of the intake damper about the intake damper shaft. This provides the aerodynamic load required for the structural design of the intake damper in the aircraft APU intake system.

[0019] S5. After the measurement and data acquisition are completed, stop the vacuum ejection and shut down the wind tunnel;

[0020] S6. Change the Mach number and intake damper opening, and repeat steps S3-S5 to obtain the damper load under other Mach numbers and different intake damper openings, thereby providing more comprehensive test data support for the design and optimization of the aircraft APU intake system.

[0021] The present invention has the following advantages over the prior art:

[0022] 1. Based on a high-speed wind tunnel test platform, this invention innovatively proposes a set of aerodynamic load measurement methods for the air intake damper of the aircraft APU air intake system. It is the first to construct a test and measurement system suitable for this specific component, effectively filling the gap in the lack of specialized measurement methods in the existing technology and changing the previous situation of relying solely on numerical simulation for evaluation.

[0023] 2. This invention fundamentally solves the technical problem that existing test equipment and methods cannot accurately measure the aerodynamic load of the APU intake damper. Through the real flow field environment of wind tunnel test, the stress state of the damper under different flight speeds and different opening angles can be more accurately reproduced, significantly improving the authenticity and accuracy of aerodynamic load data.

[0024] 3. This invention can provide comprehensive and systematic experimental data support for the overall design, performance optimization and technical verification of aircraft APU intake systems. It can not only guide the system's scheme iteration and detailed optimization, but also verify the accuracy of numerical simulation models through experimental data, thereby effectively reducing the R&D risk of the entire APU system and improving its operational safety, reliability and engineering application level. Attached Figure Description

[0025] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0026] Figure 1 This is a schematic diagram of a test device for measuring the damper load of an aircraft APU intake system. The arrow points in the direction of the incoming flow.

[0027] Figure 2 This is a schematic diagram of a lever balance.

[0028] Figure 3 A flowchart for the test to measure the damper load of the aircraft APU intake system.

[0029] In the diagram: 1-Vacuum tank, 2-External ejector pipe, 3-Flow meter, 4-Internal ejector pipe, 5-Dynamic measurement system, 6-Balance line, 7-Gas collection chamber, 8-Damper frame, 9-Large plate, 10-Wind tunnel test section, 11-Bar balance, 12-Inlet damper, 13-Inlet damper shaft, 14-Lower ear seat, 15-Straight threaded rod, 16-Setting screw, 17-Balance body, 18-Reverse threaded rod, 19-Upper ear seat. Detailed Implementation

[0030] To make the technical solutions and advantages of the embodiments of the present invention clearer, the exemplary embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0031] Example 1, Reference Figures 1-2 This embodiment describes a test apparatus for measuring the damper load of an aircraft APU intake system, comprising a test piece, a wind tunnel test section 10, a vacuum ejection system, and a measurement system.

[0032] The vacuum ejection system includes a vacuum tank 1, an external ejection pipe 2, a flow meter 3, and an internal ejection pipe 4; the vacuum tank 1, the external ejection pipe 2, the flow meter 3, and the internal ejection pipe 4 are connected in sequence.

[0033] The test piece includes a gas collection chamber 7, a damper frame 8, a large plate 9, an air intake damper 12, and an air intake damper shaft 13. The large plate 9 is provided with an installation port. One side of the large plate 9 is installed in the wind tunnel test section 10. The damper frame 8 is installed in the installation port of the large plate 9 and connected to one end of the gas collection chamber 7 pipeline. The air intake damper 12 is hinged to the damper frame 8 through the air intake damper shaft 13. The other end of the gas collection chamber 7 is connected to the ejector pipeline 4 in the tunnel.

[0034] The measurement system includes a dynamic measurement system 5, a lever balance 11, and a balance line 6; the lever balance 11 is installed on the air intake damper 12 and the large plate 9, and the balance line 6 is installed on the lever balance 11 and connected to the dynamic measurement system 5.

[0035] Furthermore, the lever balance 11 includes a lower ear seat 14, a positive threaded rod 15, a balance body 17, a negative threaded rod 18, and an upper ear seat 19. The lower ear seat 14 is mounted on the large flat plate 9, and the upper ear seat 19 is mounted on the air intake damper 12. Both the negative threaded rod 18 and the positive threaded rod 15 are provided with internal threads and are connected to the upper ear seat 19 and the lower ear seat 14 respectively through hinge pins. The balance body 17 is provided with external threads at both ends and is threadedly connected to the negative threaded rod 18 and the positive threaded rod 15. The positive and negative threads enable the lever balance 11 to extend and retract to adapt to different opening degrees of the air intake damper 12.

[0036] Furthermore, both the reverse threaded rod 18 and the forward threaded rod 15 have threaded holes on their side walls, and the set screw 16 is screwed into the threaded hole.

[0037] Example 2, Reference Figures 1-3 This embodiment describes a test method for measuring the damper load of an aircraft APU intake system. It is implemented using the test apparatus for measuring the damper load of an aircraft APU intake system described in Embodiment 1, and specifically includes the following steps:

[0038] S1. Install the test device in the wind tunnel test section 10, set up the dynamic measurement system 5 according to the test requirements, and perform joint debugging of the entire system after the setting is completed;

[0039] S2. Adjust the intake damper 12 to open it to the required opening for the test: According to the test conditions, adjust the opening of the intake damper 12 by adjusting the length of the lever balance 11. Use a digital inclinometer to measure the opening of the intake damper 12. After the opening is adjusted, use the set screw 16 to lock the positive thread rod 15 and the negative thread rod 18.

[0040] S3. Start the wind tunnel and activate the vacuum ejection system: Control and measure the flow rate of the APU intake system through flow meter 3. During the test, a vacuum ejection test with no incoming flow is first required to determine the cone position of flow meter 3 to achieve the required flow rate. During the formal wind tunnel test, move the cone position of flow meter 3 directly to that position and measure the flow rate at the same time. If the cone position is not suitable, it can be fine-tuned.

[0041] S4. Acquiring Damper Load: When the internal and external flow fields are stable and the flow rate in the pipeline of the APU intake system reaches the test requirements, the dynamic measurement system 5 is used to acquire the real-time load of the rod balance 11 to obtain the time-domain curve of the load of the intake damper 12. After obtaining the time-domain curve of its load, according to the definition of torque, the load is multiplied by the distance from the point of action of the rod balance 11 to the intake damper shaft 13 to obtain the torque of the intake damper 12 about the intake damper shaft 13, thereby obtaining the aerodynamic load required for the structural design of the intake damper 12 in the aircraft APU intake system.

[0042] S5. After the measurement and data acquisition are completed, stop the vacuum ejection and shut down the wind tunnel;

[0043] S6. Change the Mach number and the intake damper opening 12, and repeat steps S3-S5 to obtain the damper load under other Mach numbers and different intake damper opening 12, thereby providing more comprehensive test data support for the design and optimization of the aircraft APU intake system.

[0044] Furthermore, the large plate 9 is used to simulate the boundary layer in front of the aircraft APU intake system. The length of the large plate 9 in front of the damper frame 8 can be obtained from previous numerical simulations. The length of the large plate 9 behind the damper frame 8 is determined by considering both the need to avoid affecting the flow field in front and the ease of installation. The air collection chamber 7 is opened at the rear and a flange is provided for the installation of the ejector pipe while ensuring a seal.

[0045] This invention, relying on a high-speed wind tunnel testing platform, innovatively proposes a method for measuring the aerodynamic loads of the intake damper of an aircraft APU intake system. It establishes for the first time a test and measurement system suitable for this specific component, effectively filling the gap in existing technologies that lack specialized measurement methods and changing the previous reliance on numerical simulation for evaluation. Simultaneously, it fundamentally solves the technical problem that existing test equipment and methods cannot accurately measure the aerodynamic loads of the APU intake damper. Through the real flow field environment of wind tunnel testing, the stress state of the damper under different flight speeds and opening angles can be more accurately reproduced, significantly improving the authenticity and accuracy of the aerodynamic load data.

[0046] This invention provides comprehensive and systematic experimental data support for the overall design, performance optimization, and technical verification of aircraft APU intake systems. It can not only guide the system's scheme iteration and detailed optimization, but also verify the accuracy of numerical simulation models through experimental data, thereby effectively reducing the R&D risk of the entire APU system and improving its operational safety, reliability, and engineering application level.

[0047] Although the invention has been described with reference to a limited number of embodiments, those skilled in the art will understand from the foregoing description that other embodiments are conceivable within the scope of the invention described herein. Furthermore, it should be noted that the language used in this specification has been chosen primarily for readability and instructional purposes, and not for the purpose of interpreting or limiting the subject matter of the invention. Therefore, many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the appended claims. The disclosure of the invention is illustrative and not restrictive, and the scope of the invention is defined by the appended claims.

Claims

1. A test apparatus for measuring the load of an aircraft APU inlet system door, characterized in that, Includes test specimens, wind tunnel test section (10), vacuum ejection system and measurement system; The vacuum ejection system includes a vacuum tank (1), an external ejection pipeline (2), a flow meter (3), and an internal ejection pipeline (4); the vacuum tank (1), the external ejection pipeline (2), the flow meter (3), and the internal ejection pipeline (4) are connected in sequence; The test piece includes a gas collection chamber (7), a damper frame (8), a large plate (9), an air intake damper (12), and an air intake damper shaft (13). The large plate (9) has an installation port. One side of the large plate (9) is installed in the wind tunnel test section (10). The damper frame (8) is installed in the installation port of the large plate (9) and connected to one end of the gas collection chamber (7) pipeline. The air intake damper (12) is hinged to the damper frame (8) through the air intake damper shaft (13). The other end of the gas collection chamber (7) is connected to the ejector pipeline (4) in the tunnel. The measurement system includes a dynamic measurement system (5), a bar balance (11), and a balance line (6); the bar balance (11) is installed on the air intake damper (12) and the large plate (9), and the balance line (6) is installed on the bar balance (11), and the balance line (6) is connected to the dynamic measurement system (5).

2. The test device for measuring the load of the air intake system damper of an aircraft APU according to claim 1, characterized in that, The lever balance (11) includes a lower ear seat (14), a positive threaded rod (15), a balance body (17), a negative threaded rod (18), and an upper ear seat (19). The lower ear seat (14) is mounted on a large flat plate (9), and the upper ear seat (19) is mounted on an air intake damper (12). Both the negative threaded rod (18) and the positive threaded rod (15) are provided with internal threads and are connected to the upper ear seat (19) and the lower ear seat (14) respectively through hinge pins. The balance body (17) is provided with external threads at both ends and is threaded to the negative threaded rod (18) and the positive threaded rod (15).

3. An apparatus for measuring the load on an aircraft APU inlet door according to claim 2, wherein, Both the reverse threaded rod (18) and the forward threaded rod (15) have threaded holes on their side walls, and the set screw (16) is screwed into the threaded hole.

4. A test method for measuring the damper load of an aircraft APU intake system, which is implemented using the test apparatus for measuring the damper load of an aircraft APU intake system as described in claim 3, specifically including the following steps: S1. Install the test device in the wind tunnel test section (10): Set up a dynamic measurement system (5) according to the test requirements, and after setting it up, conduct joint debugging of the entire system; S2. Adjust the intake damper (12) to open the intake damper (12) to the required opening for the test: According to the test conditions, adjust the opening of the intake damper (12) by the length of the bar balance (11), and use a digital inclinometer to measure the opening of the intake damper (12). After the opening is adjusted, use the set screw (16) to lock the positive thread rod (15) and the negative thread rod (18). S3. Start the wind tunnel and turn on the vacuum ejection system: control and measure the flow rate of the APU intake system through the flow meter (3). During the test, a vacuum ejection test without incoming flow is first required to determine the cone position of the flow meter (3) to achieve the required flow rate. During the formal wind tunnel test, move the cone position of the flow meter (3) directly to that cone position and measure the flow rate at the same time. S4. Collect the damper load: When the internal and external flow fields are stable and the flow rate of the pipeline in the APU intake system reaches the test requirements, the dynamic measurement system (5) is used to collect the real-time load of the rod balance (11) to obtain the time-domain curve of the load of the intake damper (12). After obtaining the time-domain curve of its load, according to the definition of torque, the load is multiplied by the distance from the point of action of the rod balance (11) to the intake damper shaft (13) to obtain the torque of the intake damper (12) with the intake damper shaft (13) as the axis, thereby obtaining the aerodynamic load required for the structural design of the intake damper (12) in the aircraft APU intake system. S5. After the measurement and data acquisition are completed, stop the vacuum ejection and shut down the wind tunnel; S6. Change the Mach number and the opening of the intake damper (12), and repeat steps S3-S5 to obtain the damper load under other Mach numbers and different openings of the intake damper (12).

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