Full-scale nacelle acoustic test platform

Abstract

This application belongs to the field of acoustic testing technology, and specifically relates to a full-size aero-engine nacelle acoustic testing platform. It includes, from front to rear, an inlet acoustic liner assembly, a first flange section, an inlet measurement section, an aero-engine noise simulation section, an exhaust measurement section, a second flange section, and an exhaust acoustic liner assembly, as well as a hub suspended from the second flange section and the exhaust acoustic liner assembly, with the hub coaxially arranged with the exhaust acoustic liner assembly. This full-size aero-engine nacelle acoustic testing platform can simulate the working environment of a real-scale aero-engine with both inlet and exhaust acoustic liners installed simultaneously in a laboratory setting, and can perform acoustic performance testing on the nacelles.

Description

Technical Field

[0001] This application belongs to the field of acoustic testing technology, and specifically relates to a full-size acoustic testing platform for an aero-engine nacelle. Background Technology

[0002] Installing acoustic liners on aircraft engine nacelles is one of the effective methods to reduce aircraft engine noise. For testing the acoustic performance of nacelle acoustic liners, methods such as flat-plate acoustic liner tests and scaled-down acoustic liner tests are generally used. Flat-plate acoustic liner tests are mostly used to test the impedance characteristics of the acoustic liners; scaled-down acoustic liner tests are mostly used to test the acoustic performance of a single acoustic liner (inlet acoustic liner or exhaust acoustic liner) under scaled-down conditions. Currently, no existing acoustic liner testing technology can simulate the dimensions of a real aircraft engine nacelle or test the acoustic performance under conditions where both inlet and exhaust acoustic liners are installed simultaneously.

[0003] 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

[0004] The purpose of this application is to provide a full-size acoustic test platform for an aircraft engine nacelle to solve at least one problem existing in the prior art.

[0005] The technical solution of this application is:

[0006] A full-scale acoustic test platform for aircraft engine nacelles includes:

[0007] The intake duct measuring section, the front end of which is connected to the intake duct acoustic liner assembly via a first flange section;

[0008] An aircraft engine noise simulation section, the front end of which is connected to the rear end of the air intake measurement section;

[0009] The exhaust duct measurement section has its front end connected to the rear end of the aero-engine noise simulation section, and its rear end connected to the exhaust duct acoustic liner assembly via a second flange section.

[0010] The wheel hub is suspended on the second flange section and the exhaust duct acoustic liner assembly, and the wheel hub and the exhaust duct acoustic liner assembly are coaxially arranged.

[0011] The overall structure consisting of the air intake acoustic liner assembly, the first flange section, the air intake measurement section, the aircraft engine noise simulation section, the exhaust measurement section, the second flange section, the exhaust acoustic liner assembly, and the wheel hub is fixed to the bottom frame by multiple support arms.

[0012] In at least one embodiment of this application, the support arm comprises six arms, which are divided into three groups to fix the first flange section, the aircraft engine noise simulation section, the second flange section, and the bottom frame, respectively.

[0013] In at least one embodiment of this application, an electric flatbed cart is also included, on which the bottom frame is mounted.

[0014] In at least one embodiment of this application, the intake duct acoustic liner assembly includes a first acoustic liner top plate, an intake duct acoustic liner, a first mounting frame, and a first lip, wherein,

[0015] The intake acoustic liner is inserted into the first mounting frame. The first lip is installed at the front end of the first mounting frame, and the first acoustic liner top plate is installed at the rear end of the first mounting frame. The rear end of the first mounting frame is connected to the first flange section through a flange plate.

[0016] In at least one embodiment of this application,

[0017] The intake measurement section uses a microphone array to test the characteristics of the forward and backward noise sources emitted by the aero-engine noise simulation section.

[0018] The exhaust duct measurement section uses a microphone array to test the characteristics of the front and rear noise sources emitted by the aircraft engine noise simulation section.

[0019] In at least one embodiment of this application, a rotating mode generator or a rotor fan is used as the sound source for the simulated aircraft engine noise segment.

[0020] In at least one embodiment of this application, the rotating mode generator includes a simulated pipe with multiple waveguides evenly distributed around its circumference, and a loudspeaker is provided on the waveguide.

[0021] In at least one embodiment of this application, the rotor fan includes a rotor head cone, a single-stage rotor fan, a single-stage stator fan, a rear hub connected in sequence, and a hub housing mounted on the single-stage stator fan.

[0022] In at least one embodiment of this application, the exhaust duct acoustic liner assembly includes a second acoustic liner top plate, an exhaust duct acoustic liner, a second mounting frame, and a second lip, wherein,

[0023] The exhaust duct acoustic liner is inserted into the second mounting frame. The second acoustic liner top plate is installed at the front end of the second mounting frame, and the second lip is installed at the rear end of the second mounting frame. The front end of the second mounting frame is connected to the second flange section through a flange plate.

[0024] In at least one embodiment of this application, the wheel hub includes a front hemisphere, a hub intermediate body, and a rear cone. The front end of the hub intermediate body extends forward with a mating ring, which is connected to the front hemisphere by a radially installed screw. The rear end of the hub intermediate body is connected to the rear cone through an inner flange. The front end of the hub intermediate body is suspended on the second flange section by a stud, and the rear end is suspended on the lip by a stud.

[0025] The invention has at least the following beneficial technical effects:

[0026] The full-size aero-engine nacelle acoustic test platform of this application can simulate the working environment of an aero-engine with both the nacelle inlet acoustic liner and the exhaust acoustic liner installed on a real scale in a laboratory environment, and test its acoustic performance. Attached Figure Description

[0027] Figure 1 This is an overall schematic diagram of a full-size aero-engine nacelle acoustic test platform according to one embodiment of this application;

[0028] Figure 2 This is a schematic diagram of a rotating mode generator according to one embodiment of this application;

[0029] Figure 3 This is a schematic diagram of an exhaust duct acoustic liner assembly according to one embodiment of this application;

[0030] Figure 4 This is a schematic diagram of a wheel hub according to one embodiment of this application;

[0031] Figure 5 This is a schematic diagram of a rotor fan according to one embodiment of this application.

[0032] in:

[0033] 1-Intake duct acoustic liner assembly; 2-First flange section; 3-Intake duct measurement section; 4-Air engine noise simulation section; 41-Speaker; 42-Waveguide; 43-Simulation duct; 44-Rotor head cone; 45-Single-stage rotor fan; 46-Single-stage stator fan; 47-Rear wheel hub; 48-Wheel hub shell; 5-Exhaust duct measurement section; 6-Second flange section; 7-Exhaust duct acoustic liner assembly; 71-Second acoustic liner top plate; 72-Exhaust duct acoustic liner; 73-Second mounting frame; 74-Second lip; 8-Wheel hub; 81-Front end hemisphere; 82-Wheel hub intermediate body; 83-Tail end cone; 9-Bottom frame; 10-Electric flatbed truck. 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 1 to 5 This application will be described in further detail.

[0037] This application provides a full-size acoustic test platform for an aero-engine nacelle, including: an intake acoustic liner assembly 1, a first flange section 2, an intake measurement section 3, an aero-engine noise simulation section 4, an exhaust measurement section 5, a second flange section 6, an exhaust acoustic liner assembly 7, and a hub 8.

[0038] Specifically, such as Figure 1As shown, the intake duct acoustic liner assembly 1 simulates the geometry of a real aircraft engine nacelle intake through its external structure, providing a realistic engine intake shape. The front end of the intake duct measurement section 3 is connected to the intake duct acoustic liner assembly 1 via the first flange section 2. The front end of the aircraft engine noise simulation section 4 is connected to the rear end of the intake duct measurement section 3. The front end of the exhaust duct measurement section 5 is connected to the rear end of the aircraft engine noise simulation section 4. The rear end of the exhaust duct measurement section 5 is connected to the exhaust duct acoustic liner assembly 7 via the second flange section 6. The wheel hub 8 is suspended in the designated position on the exhaust duct frame by a suspension method, and the wheel hub 8 and the exhaust duct acoustic liner assembly 7 are coaxially arranged. The front first flange section 2 and the rear second flange section 6 are the front and rear support points of the test platform, respectively, and connect the intake duct acoustic liner assembly 1 to the intake duct measurement section 3, and the exhaust duct measurement section 5 to the exhaust duct acoustic liner assembly 7. The main structure of the test platform is supported by the bottom frame 9. The overall structure consisting of the air intake acoustic liner assembly 1, the first flange section 2, the air intake measurement section 3, the aero-engine noise simulation section 4, the exhaust measurement section 5, the second flange section 6, the exhaust acoustic liner assembly 7, and the wheel hub 8 is fixed to the bottom frame 9 by multiple support arms.

[0039] In a preferred embodiment of this application, the support arms include six arms, which are divided into three groups in pairs. The first flange section 2 extends two arms along both sides of the test piece as fixed arms, the aero-engine noise simulation section 4 extends two arms as fixed arms, and the second flange section 6 also has two arms extending laterally as fixed arms. The six arms are fixed to the bottom frame 9 by supports. The bottom of the bottom frame 9 is made of square tube welded together, and the two sides are made of channel steel welded together, forming an integral structure through welding.

[0040] In a preferred embodiment of this application, the bottom frame 9 is mounted on the electric flatbed trolley 10, and the overall structure is moved by the electric flatbed trolley 10 at the bottom. The bottom frame 9 is fixed to the electric flatbed trolley 10 through the holes reserved at the top of the electric flatbed trolley 10, and the electric flatbed trolley 10 drives the overall test platform to move through the electric drive mechanism.

[0041] In a preferred embodiment of this application, the intake duct acoustic liner assembly 1 is a full-size intake duct acoustic liner assembly 1, including a first acoustic liner top plate, an intake duct acoustic liner, a first mounting frame, and a first lip. The intake duct acoustic liner is inserted into the first mounting frame. The first lip is installed at the front end of the first mounting frame, and the first acoustic liner top plate is installed at the rear end of the first mounting frame. The rear end of the first mounting frame is connected to the first flange section 2 through a flange plate.

[0042] In a preferred embodiment of this application, a rotating modal generator or a rotor fan is used as the sound source for the aircraft engine noise simulation section 4. The aircraft engine noise simulation section 4, through proper design in a laboratory environment, can emit sound sources of specified frequencies and modes. Furthermore, the characteristics of the forward and backward noise sources emitted by the aircraft engine noise simulation section 4 can be tested by using a properly designed microphone array to form the inlet measurement section 3 and the exhaust measurement section 5. Alternatively, the far-field radiation characteristics of the forward and backward noise emitted by the aircraft engine noise simulation section 4 can be tested by using a properly designed far-field microphone array.

[0043] The full-scale aero-engine nacelle acoustic test platform of this application features a replaceable design for the aero-engine noise simulation section 4, supporting multiple sound generation methods. In one embodiment of this application, such as... Figure 2 As shown, the aircraft engine noise simulation section 4 is a rotating mode generator, including a loudspeaker 41, a waveguide 42, and a simulated pipe 43. The entire assembly is welded from 304 stainless steel. The front and rear ends of the simulated pipe 43 are connected to adjacent components via flanges. With the center of the flange plate as the center, 24 circular holes are evenly distributed on the outer circumference as its end fixing method. The channel signal generator produces multiple electrical signals with the same frequency but different phases. These signals are amplified by a corresponding number of power amplifiers and transmitted to the loudspeaker 41. The sound emitted by the loudspeakers 41, arranged circumferentially around the simulated pipe 43, enters the inner surface of the simulated pipe 43 through the waveguide 42, forming a rotating sound source. This rotating sound source can replace the noise at the fan blade passage frequency or its harmonic frequencies.

[0044] The full-size aero-engine nacelle acoustic test platform of this application uses an exhaust duct acoustic liner assembly 7, which primarily simulates the shape of a real engine exhaust duct through its external structure. In this embodiment, the exhaust duct acoustic liner assembly 7 and the intake duct acoustic liner assembly 1 adopt a similar structure, such as... Figure 3As shown, the exhaust duct acoustic liner assembly 7 mainly includes components such as a second acoustic liner top plate 71, an exhaust duct acoustic liner 72, a second mounting frame 73, and a second lip 74. The second exhaust duct acoustic liner 72 is inserted from the front end of the second mounting frame 73 and pressed against it by the second acoustic liner top plate 71, which is fixed to the second mounting frame 73 by outer ring screws. The front end of the second mounting frame 73 is connected to the second flange section 6 via a flange plate, and the rear end of the second mounting frame 73 is equipped with a second lip 74. The assembly relationship between the components can be described as follows: the second acoustic liner top plate 71, the exhaust duct acoustic liner 72, the second mounting frame 73, and the second lip 74 are axially aligned; the rear end face of the exhaust duct acoustic liner 72 is aligned with the inner side of the flange plate of the second mounting frame 73, ensuring that the end face and inner circle at the joint are flat; the front end face of the exhaust duct acoustic liner 72 is aligned with the corresponding end face of the second acoustic liner top plate 71, and the end face at the joint is flat with the inner circle; the upper end face of the second acoustic liner top plate 71 is aligned with the concave plane of the second mounting frame 73, and is screwed onto the front flange plate of the second mounting frame 73 by countersunk screws; the coaxiality of the exhaust duct acoustic liner 72 and the other components is adjusted by the tightening screws evenly distributed on the second mounting frame 73.

[0045] The full-size aero-engine nacelle acoustic test platform of this application primarily simulates the shape of a real engine hub through its external structure. Considering structural feasibility, in this embodiment, as... Figure 4As shown, the wheel hub 8 is divided into three sections: a front hemisphere 81, a middle section 82, and a rear cone 83. To ensure surface rigidity and minimize weight, all three sections are covered with 4mm thick fiberglass skin on both the inner and outer surfaces, connected as a whole. A foam layer is used as a reinforcing material in the fiberglass layer, and aluminum plates are used as support structures at the flange joints of each component. An L-shaped annular plate is used at the joint between the hemisphere and the middle section to strengthen the joint's strength and rigidity. A ring extends from the front joint of the middle section 82 to serve as the joint surface for the front hemisphere 81; a ring is pre-embedded at the front joint, and a flange plate is pre-embedded at the end face. The rear end of the middle section 82 connects to the rear structure using an inner flange; the inner diameter of the pre-embedded flange plate is smaller than the inner diameter of the middle section, and the protruding part is the bolt connection point for the flange. The front end of the rear cone 83 connects to the middle section 82 using an inner flange; a flange plate is pre-embedded at the joint, with an inner diameter smaller than the inner diameter of the cavity; the protruding part is the bolt connection point for the flange. The tip of the tail cone 83 is directly machined from aluminum alloy. A connector pre-embedded within the tail cone allows the tip to be screwed to the tail of the cone. The three parts are connected as follows: the front hemisphere 81 is connected to the hub intermediate body 82 via an insertion connection; the flange of the front hemisphere 81 is inserted into the protruding ring of the hub intermediate section 82 and fixed radially with screws. The hub intermediate body 82 and the tail cone 83 are connected by an internal flange and bolts. The hub 8 is suspended on the test platform using four threaded holes on the two end faces of the hub intermediate body 82, suspended by double-ended studs. The front end is suspended by studs to the rear second flange section 6, and the rear end is suspended by studs to the lip 74.

[0046] In another embodiment of this application, such as Figure 5 As shown, a rotor fan can also be used as the sound source for the aero-engine noise simulation section 4. A single-stage rotor fan mainly includes a rotor head cone 44, a single-stage rotor fan 45, a single-stage stator fan 46, a rear hub 47, and a hub housing 48. In specific implementation, the rotor fan completely replaces the rotating sound mode generator, while the connection method with other upstream and downstream parts remains unchanged. In addition, the rotor head cone 44 replaces the front hemisphere 81, and the rear hub 47 replaces the hub intermediate body 82, with the connection method remaining unchanged. It should be noted that regardless of the design adopted, the sound emitted by the aero-engine noise simulation section 4 must have fan noise characteristics. That is, under different operating conditions, the main noise component of the fan noise is the rotating mode noise corresponding to the blade passage frequency and its harmonic frequencies. Therefore, the sound source must reflect the blade passage frequency and its corresponding rotating sound mode. Under the premise of meeting acoustic conditions, the interface of this replacement design should be compatible with the interfaces of the upstream and downstream connection sections.

[0047] The full-size aero-engine nacelle acoustic test platform of this application, through the combination of the above key components, can simulate the working environment of an aero-engine with both the nacelle inlet acoustic liner and the exhaust acoustic liner installed on a real scale in a laboratory environment, and test their acoustic performance. Through reasonably designed measurement methods, the acoustic performance of the inlet acoustic liner and the exhaust acoustic liner can be obtained.

[0048] 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 full-size acoustic test platform for an aircraft engine nacelle, characterized in that, include: The front end of the intake duct measuring section (3) is connected to the intake duct acoustic liner assembly (1) through the first flange section (2); The front end of the aircraft engine noise simulation section (4) is connected to the rear end of the air intake measurement section (3); The exhaust duct measurement section (5) is connected at its front end to the rear end of the aircraft engine noise simulation section (4), and the rear end of the exhaust duct measurement section (5) is connected to the exhaust duct acoustic liner assembly (7) via a second flange section (6). The hub (8) is suspended on the second flange section (6) and the exhaust duct acoustic liner assembly (7), and the hub (8) and the exhaust duct acoustic liner assembly (7) are coaxially arranged. The overall structure consisting of the intake acoustic liner assembly (1), the first flange section (2), the intake measurement section (3), the aircraft engine noise simulation section (4), the exhaust measurement section (5), the second flange section (6), the exhaust acoustic liner assembly (7), and the wheel hub (8) is fixed to the bottom frame (9) by multiple support arms.

2. The full-size aero-engine nacelle acoustic test platform according to claim 1, characterized in that, The support arm comprises six arms, which are divided into three groups, respectively connecting the first flange section (2), the aircraft engine noise simulation section (4), the second flange section (6), and the bottom frame (9).

3. The full-size aero-engine nacelle acoustic test platform according to claim 2, characterized in that, It also includes an electric flatbed cart (10), on which the bottom frame (9) is mounted.

4. The full-size aero-engine nacelle acoustic test platform according to claim 3, characterized in that, The intake acoustic liner assembly (1) includes a first acoustic liner top plate, an intake acoustic liner, a first mounting frame, and a first lip, wherein, The intake acoustic liner is inserted into the first mounting frame. The first lip is installed at the front end of the first mounting frame, and the first acoustic liner top plate is installed at the rear end of the first mounting frame. The rear end of the first mounting frame is connected to the first flange section (2) through a flange plate.

5. The full-size aero-engine nacelle acoustic test platform according to claim 1, characterized in that, The air intake measurement section (3) uses a microphone array to test the characteristics of the forward and backward noise sources emitted by the aero-engine noise simulation section (4). The exhaust duct measurement section (5) uses a microphone array to test the characteristics of the forward and backward noise sources emitted by the aircraft engine noise simulation section (4).

6. The full-size aero-engine nacelle acoustic test platform according to claim 1, characterized in that, The noise source for the simulated section (4) of the aircraft engine noise is a rotating modal generator or a rotor fan.

7. The full-size aero-engine nacelle acoustic test platform according to claim 6, characterized in that, The rotating mode generator includes a simulated pipe (43), on which multiple waveguides (42) are evenly distributed in the circumference, and a loudspeaker (41) is provided on the waveguides (42).

8. The full-size aero-engine nacelle acoustic test platform according to claim 6, characterized in that, The rotor fan includes a rotor head cone (44), a single-stage rotor fan (45), a single-stage stator fan (46), a rear hub (47) connected in sequence, and a hub housing (48) mounted on the single-stage stator fan (46).

9. The full-size aero-engine nacelle acoustic test platform according to claim 7, characterized in that, The exhaust duct acoustic liner assembly (7) includes a second acoustic liner top plate (71), an exhaust duct acoustic liner (72), a second mounting frame (73), and a second lip (74), wherein, The exhaust duct acoustic liner (72) is inserted into the second mounting frame (73). The front end of the second mounting frame (73) is equipped with the second acoustic liner top plate (71), and the rear end of the second mounting frame (73) is equipped with the second lip (74). The front end of the second mounting frame (73) is connected to the second flange section (6) through a flange plate.

10. The full-size aero-engine nacelle acoustic test platform according to claim 9, characterized in that, The hub (8) includes a front hemisphere (81), a hub intermediate body (82), and a rear cone (83). The front end of the hub intermediate body (82) extends forward with a mating ring, which is connected to the front hemisphere (81) by a radially installed screw. The rear end of the hub intermediate body (82) is connected to the rear cone (83) through an inner flange. The front end of the hub intermediate body (82) is suspended on the second flange section (6) by a stud, and the rear end is suspended on the second lip (74) by a stud.

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