Engine test bench nacelle middle section structure

Abstract

The application belongs to the technical field of aircraft structure design, and particularly relates to an engine test stand nacelle middle section structure. The engine test stand nacelle middle section structure comprises an internal frame, one end of the internal frame is connected with an air inlet duct, and the other end is connected with a test stand through a stand connecting piece; a cabin door is installed on the internal frame; and an external skin is wrapped outside the internal frame. The engine test stand nacelle middle section structure adopts a connecting piece to connect the nacelle middle section structure on the engine test stand, keeps the connection form of the existing components unchanged, meets the requirements of structure separation design and shape continuity with the air inlet duct, has a simple structure, is easy to process, and has strength and rigidity meeting actual requirements, so that the needs of engine test can be better met.

Description

Technical Field

[0001] This application belongs to the field of aircraft structural design technology, and specifically relates to a mid-section structure of an engine test bench nacelle. Background Technology

[0002] Compared to piston engines, turboprop engines offer advantages such as a higher power-to-weight ratio and lower vibration, with performance becoming even more superior as flight altitude increases. Compared to turbojet and turbofan engines, they boast lower fuel consumption, higher thrust, and superior low-speed (400-800 km / h) flight performance. Therefore, turboprop engines are widely used in regional airliners, military transport aircraft, and long-endurance unmanned aerial vehicles (UAVs). Testing the engine's performance before installation is essential for obtaining its operating parameters and understanding its actual operating conditions, and test benches are a crucial foundation for supporting these tests. Current test benches include air intakes, engine mounting rods, and engine mounting frames, exposing the engine body and system accessories. This makes the engine more susceptible to the influence of external environmental factors such as weather. Furthermore, the slipstream generated by the rotating propeller has complex flow characteristics, which can interfere with downstream components, altering the aerodynamic characteristics of the propeller and aircraft aerodynamic components.

[0003] The nacelle, as a crucial structure closely related to the engine, provides functions such as airflow rectification and protection of internal accessories. This paper designs a mid-section structure for the nacelle on a turboprop engine test bench. This structure better simulates the actual operating conditions of the engine while meeting the requirements for covering engine system accessories (left and right cable boxes, propeller pump, vent box, and front control box, etc.), protecting internal piping and other accessory facilities, and also achieving an aesthetically pleasing appearance. Maintaining the existing connection methods of components, ensuring continuity with the air intake shape, and meeting the requirements for convenient engine disassembly, installation, and maintenance presents numerous design challenges.

[0004] 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

[0005] The purpose of this application is to provide a mid-section structure for an engine test bench nacelle to solve at least one problem existing in the prior art.

[0006] The technical solution of this application is:

[0007] A mid-section structure of an engine test bench nacelle includes:

[0008] An internal frame, one end of which is connected to the air intake, and the other end of which is connected to the test bench via a bench connector;

[0009] A hatch, which is mounted on the internal frame;

[0010] An outer skin that covers the exterior of the inner frame.

[0011] In at least one embodiment of this application, the internal framework includes:

[0012] The upper partition is provided with an upper cover connector, and the front end of the upper partition has an upper connecting part for the air intake.

[0013] The upper beam includes a left upper beam and a right upper beam, which are symmetrically installed on the upper bulkhead, and both the left upper beam and the right upper beam are equipped with hatch suspension joints.

[0014] A front partition, wherein the front partition is disposed at the lower end of the upper air intake connecting portion of the upper partition;

[0015] The lower partition has an air intake manifold lower docking part at its front end, which is located at the lower end of the front partition. The lower partition is provided with a partition connector, a lower skin longitudinal member, a mouth frame, and a lubricating oil radiator exhaust pipe connecting rod.

[0016] The lower beam includes a left lower beam and a right lower beam, which are symmetrically installed on the lower bulkhead, and both the left lower beam and the right lower beam are equipped with hatch lock seats.

[0017] In at least one embodiment of this application, the upper beam includes an upper beam flange, an upper beam web, and an upper beam support, and three hatch suspension joints are evenly arranged on the upper beam web.

[0018] In at least one embodiment of this application, the upper docking portion of the air intake, the front bulkhead, and the lower docking portion of the air intake together form an air intake docking portion, and the air intake docking portion and the nacelle air intake have a 5mm circumferential gap.

[0019] In at least one embodiment of this application, a rubber profile is provided on the intake manifold docking portion via a pressure plate, and the rubber profile has a P-shaped cross-section.

[0020] In at least one embodiment of this application, the platform connector is connected to the upper beam and the lower beam by bolts.

[0021] In at least one embodiment of this application, the hatch includes a left hatch and a right hatch, and both the left hatch and the right hatch include:

[0022] The hatch body;

[0023] Three rocker arms are evenly installed on the hatch body, and the three rocker arms are respectively connected to the corresponding hatch suspension joints.

[0024] A hatch lock is mounted on the hatch body via a lock seat, and the hatch lock can cooperate with the hatch lock seat to lock the hatch.

[0025] The hatch support rod is mounted on the hatch body via a support rod base. When the hatch is closed, the hatch support rod is retracted to the inside of the hatch. When the hatch is open, the hatch support rod rotates and connects to the base of the fixed frame connector.

[0026] In at least one embodiment of this application, the opening angle of the left hatch and the right hatch is 65°.

[0027] In at least one embodiment of this application, the outer skin includes an upper skin and a lower skin.

[0028] The upper skin covers the outside of the upper partition, and a maintenance cover is provided on the upper skin. The upper skin is fixedly installed by the upper partition and the upper cover connector.

[0029] The lower skin covers the outside of the lower partition plate. The lower skin adopts a honeycomb sandwich structure and has a skin bulge at the feathering pump. The lower skin is fixedly installed by the lower partition plate and the partition plate connector.

[0030] In at least one embodiment of this application, the lower skin is provided with an oil cooler exhaust pipe damper opening.

[0031] The invention has at least the following beneficial technical effects:

[0032] The engine test bench nacelle mid-section structure of this application uses connectors to connect the nacelle mid-section structure to the engine test bench, while maintaining the existing connection form of the components. At the same time, it meets the requirements of structural separation design from the air intake and continuous shape. The structure is simple, easy to process, and the strength and rigidity meet the actual needs, which can better meet the needs of engine testing. Attached Figure Description

[0033] Figure 1 This is an overall schematic diagram of the mid-section structure of the engine test bench nacelle according to one embodiment of this application;

[0034] Figure 2 This is a schematic diagram of the internal framework of one embodiment of this application;

[0035] Figure 3 This is a schematic diagram of the upper beam according to one embodiment of this application;

[0036] Figure 4 This is a schematic diagram of the connection part with the air intake in one embodiment of this application;

[0037] Figure 5 This is a schematic diagram of a hatch according to one embodiment of this application;

[0038] Figure 6 This is a schematic diagram of the upper skin of one embodiment of this application;

[0039] Figure 7 This is a schematic diagram of the lower skin of one embodiment of this application.

[0040] in:

[0041] 1-Internal frame; 2-External skin; 3-Hatch door; 4-Frame connector; 5-Upper beam; 6-Lower beam; 7-Upper bulkhead; 8-Front bulkhead; 9-Lower bulkhead; 10-Bulkhead connector; 11-Upper cover connector; 12-Lower skin longitudinal component; 13-Hatch frame; 14-Hatch door suspension joint; 15-Oil radiator exhaust pipe connecting rod; 16-Upper skin; 17-Lower skin; 18-Upper beam flange; 19-Upper beam web; 20-Upper beam support; 21-Hatch door lock seat; 22-Hatch door body; 23-Rocker arm; 24-Hatch door lock; 25-Lock seat; 26-Hatch door strut; 27-Strut base; 28-Rubber profile; 29-Pressure plate; 30-Maintenance cover; 31-Honeycomb sandwich structure; 32-Skin bulge. Detailed Implementation

[0042] 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.

[0043] 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.

[0044] The following is in conjunction with the appendix Figures 1 to 7 This application will be described in further detail.

[0045] This application provides a mid-section structure of an engine test bench nacelle, including an internal frame 1, an external skin 2, a hatch 3, and a test bench connector 4.

[0046] Specifically, such as Figure 1 As shown, one end of the internal frame 1 is connected to the air intake, and the other end is connected to the test bench through the test bench connector 4; the hatch 3 is installed on the internal frame 1; the outer skin 2 covers the outside of the internal frame 1.

[0047] The engine test bench nacelle mid-section structure of this application, such as Figure 2 As shown, the internal frame 1 includes: an upper partition 7, an upper beam 5, a front partition 8, a lower partition 9, and a lower beam 6. The upper bulkhead 7 is provided with an upper cover connector 11, and the front end of the upper bulkhead 7 has an upper air intake docking part; the upper beam 5 includes a left upper beam and a right upper beam, which are symmetrically installed on the upper bulkhead 7, and both the left and right upper beams are equipped with hatch suspension joints 14. The single and double lugs of the hatch suspension joint 14 should have sufficient parallelism to meet the connection requirements; the front bulkhead 8 is located at the lower end of the upper air intake docking part of the upper bulkhead 7; the front end of the lower bulkhead 9 has a lower air intake docking part, which is located at the lower end of the front bulkhead 8, and the lower bulkhead 9 is provided with a bulkhead connector 10, a lower skin longitudinal member 12, a mouth frame 13, and a lubricating oil radiator exhaust pipe connecting rod 15; the lower beam 6 includes a left lower beam and a right lower beam, which are symmetrically installed on the lower bulkhead 9, and both the left and right lower beams are equipped with hatch lock seats 21.

[0048] In the preferred embodiment of this application, such as Figure 3 As shown, the upper beam 5 adopts a channel beam structure, including an upper beam flange 18, an upper beam web 19, and an upper beam support 20. Three hatch suspension joints 14 are evenly distributed on the upper beam web 19. The lower beam 6 adopts a similar design, with two hatch lock seats 21 arranged on the lower beam web. The lower beam web and lower beam support are arranged and designed accordingly.

[0049] In the preferred embodiment of this application, such as Figure 4 As shown, the upper inlet docking portion of the upper bulkhead 7, the lower inlet docking portion of the front bulkhead 8, and the lower inlet docking portion of the lower bulkhead 9 together form the inlet docking portion. The inlet docking portion forms the designed separation surface from the nacelle inlet structure and is not structurally connected. A 5mm circumferential gap is provided between the inlet docking portion and the nacelle inlet. To ensure the continuity of the nacelle midsection and the nacelle inlet structure in terms of shape and to achieve structural sealing, rubber profiles 28 are arranged on the upper inlet docking portion of the upper bulkhead 7, the front bulkhead 8, and the lower inlet docking portion of the lower bulkhead 9. The rubber profiles 28 have a P-shaped cross-section and are fixed to the corresponding bulkheads by pressure plates 29.

[0050] In a preferred embodiment of this application, the test bench connector 4 is connected to the upper beam 5 and the lower beam 6 by bolts. The nacelle mid-section structure is connected to the test bench connector 4 via the left and right upper beams and left and right lower beams of the internal frame 1 using bolt sets. The test bench connector 4 is fixed to the test bench by bolt sets. The left and right upper beams are connected to the test bench connector 4 by 12 M10 bolts (on both sides), the left and right lower beams are connected to the test bench connector 4 by 16 M10 bolts (on both sides), and the test bench connector 4 is connected to the test bench by 46 M12 bolts (on both sides). The test bench is designed with bolts of the same diameter at corresponding positions for bolt connection, and the bolts and bolt holes are assembled with a small clearance fit. The nacelle mid-section has a designed separation surface at the test bench connector 4. First, the test bench connector 4 is positioned and installed, and then fixed to the test bench by bolt sets. Then, the nacelle mid-section is fixed to the test bench connector 4. The preferred material for the frame connector 4 is 30CrMnSiA, which is integrally machined.

[0051] The engine test bench nacelle mid-section structure of this application includes a hatch 3 comprising a left hatch and a right hatch. Each hatch includes a hatch body 22, a rocker arm 23, a hatch lock 24, and a hatch support rod 26. Three rocker arms 23 are evenly mounted on the hatch body 22, and each rocker arm 23 is connected to a corresponding hatch suspension joint 14. The hatch lock 24 is mounted on the hatch body 22 via a lock seat 25, and the hatch lock 24 can cooperate with the hatch lock seat 21 to lock the hatch. The hatch support rod 26 is mounted on the hatch body 22 via a support rod base 27. In the closed state, the hatch support rod 26 is retracted inside the hatch; in the open state, the hatch support rod 26 rotates and connects to the base of the fixed test bench connector 4. In this application, the left and right hatch structures are connected to the hatch suspension joints 14 via three correspondingly arranged rocker arms 23. Each hatch 3 has two hatch locks 24, which are respectively connected to two hatch lock seats 21 fixed on the web plates of the left and right lower beams, realizing the opening and closing of the hatch 3. Each hatch 3 has a hatch support rod 26. In the closed state, the hatch support rod 26 is retracted to the inside of the hatch. In the open state, the hatch support rod 26 rotates and is connected to the base fixed on the platform connector 4, realizing the support and fixation of the hatch in the open state. The opening angle of a single hatch is 65°.

[0052] In a preferred embodiment of this application, the outer skin 2 includes an upper skin 16 and a lower skin 17. The upper skin 16 covers the outside of the upper partition 7. The upper skin 16 is made of medium-temperature epoxy resin glass fabric. A maintenance cover 30 is provided on the upper skin 16. The size of the maintenance cover 30 is determined according to the maintenance channel requirements. The upper skin 16 and the maintenance cover 30 are fixedly installed by the upper partition 7 and the upper cover connector 11. The lower skin 17 covers the outside of the lower partition 9. The lower skin 17 adopts a honeycomb sandwich structure 31. The inner and outer panel materials are made of medium-temperature curing epoxy resin glass fabric, and the honeycomb is made of aramid paper honeycomb core material. The lower skin 17 has a skin bulge 32 at the feather pump, which covers the shape of the feather pump and also serves as a maintenance cover. The lower skin 17 and the skin bulge 32 are fixedly installed by the lower partition 9 and the partition connector 10. The skin bulge 32 can be disassembled separately. The skin bulge 32 has a complex shape and small size, and adopts a composite material layer structure. The material is medium-temperature curing epoxy resin glass fabric. The lower skin 17 structure is equipped with an oil radiator exhaust pipe damper opening to keep the oil radiator exhaust pipe in the same installation position.

[0053] Understandably, considering factors such as engine vibration, bolted connections should be designed with appropriate anti-loosening devices to ensure the reliability of the connection, and the mid-section structure of the nacelle should have sufficient rigidity so as not to affect the disassembly, assembly, and maintenance of the engine and accessories.

[0054] The engine test bench nacelle mid-section structure of this application was constructed according to design requirements. Firstly, the fixed installation position of the nacelle mid-section structure on the test bench was coordinated, and the existing system accessories (left and right cable boxes, propeller pump, vent box, and front-end control box, etc.) of the nacelle mid-section were covered. Simultaneously, the design of the nacelle mid-section structure and the intake structure were separated, and the shape was made continuous. The connection point and structural form between the nacelle mid-section structure and the oil cooler exhaust pipe remained unchanged, as did the shape of the connection area between the nacelle mid-section structure and the oil cooler exhaust pipe, the oil cooler exhaust pipe damper, and the distance between the oil cooler exhaust pipe and the test bench. Furthermore, considering the disassembly, installation, and maintenance needs of engine accessories, the constructed shape underwent smooth transitions and modifications, completing the external shape design of the engine nacelle mid-section structure of the test bench. The propeller pump protruding on the right side of the test bench in the forward direction has a very large external dimension, which cannot be accommodated by simply expanding the overall shape. Therefore, a local bulge was adopted to solve this problem, and the shape at the bulge was smoothed and modified.

[0055] The engine test bench nacelle mid-section structure of this application uses connectors to link the nacelle mid-section structure to the engine test bench, maintaining the existing component connection methods while meeting the requirements for structural separation from the air intake and continuous external shape. The structure is simple, easy to manufacture, and its strength and rigidity meet practical needs, better fulfilling the requirements of engine testing. It facilitates engine disassembly and maintenance, demonstrating the feasibility of the solution. While meeting structural functional requirements, it strives to reduce structural weight, complying with aircraft design specifications, and provides a reference for the construction of engine test benches.

[0056] 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 mid-section structure of a short nacelle on an engine test bench, characterized in that, include: An internal frame (1) is connected at one end to the air intake and at the other end to the test bench via a bench connector (4). A hatch (3) is mounted on the internal frame (1); An outer skin (2) covers the outside of the inner frame (1); The internal framework (1) includes: The upper partition (7) is provided with an upper cover connector (11), and the front end of the upper partition (7) has an upper connecting part of the air intake channel; The upper beam (5) includes a left upper beam and a right upper beam. The left upper beam and the right upper beam are symmetrically installed on the upper bulkhead (7), and both the left upper beam and the right upper beam are equipped with door suspension joints (14). Front partition (8), the front partition (8) is disposed at the lower end of the upper air intake connecting part of the upper partition (7); The lower partition (9) has an air intake lower docking part at its front end. The air intake lower docking part is located at the lower end of the front partition (8). The lower partition (9) is provided with a partition connector (10), a lower skin longitudinal member (12), a mouth frame (13), and a lubricating oil radiator exhaust pipe connecting rod (15). The lower beam (6) includes a left lower beam and a right lower beam. The left lower beam and the right lower beam are symmetrically installed on the lower bulkhead (9), and both the left lower beam and the right lower beam are equipped with door lock seats (21).

2. The engine test bench nacelle mid-section structure according to claim 1, characterized in that, The upper beam (5) includes an upper beam edge strip (18), an upper beam web (19), and an upper beam support (20). Three of the hatch suspension joints (14) are evenly arranged on the upper beam web (19).

3. The engine test bench nacelle mid-section structure according to claim 2, characterized in that, The upper connecting part of the air intake, the front bulkhead (8) and the lower connecting part of the air intake together form the air intake connecting part, and there is a 5mm gap between the air intake connecting part and the nacelle air intake in the circumferential direction.

4. The engine test bench nacelle mid-section structure according to claim 3, characterized in that, A rubber profile (28) is provided on the intake manifold joint via a pressure plate (29), and the rubber profile (28) has a P-shaped cross section.

5. The engine test bench nacelle mid-section structure according to claim 4, characterized in that, The platform connector (4) is connected to the upper beam (5) and the lower beam (6) by bolts.

6. The engine test bench nacelle mid-section structure according to claim 5, characterized in that, The hatch (3) includes a left hatch and a right hatch, and both the left hatch and the right hatch include: Hatch body (22); The rocker arms (23) include three, which are evenly installed on the hatch body (22), and the three rocker arms (23) are respectively connected to the corresponding hatch suspension joints (14); The hatch lock (24) is installed on the hatch body (22) via a lock seat (25). The hatch lock (24) can cooperate with the hatch lock seat (21) to lock the hatch. The hatch support rod (26) is installed on the hatch body (22) via the support rod base (27). In the hatch closed state, the hatch support rod (26) is retracted to the inside of the hatch. In the hatch open state, the hatch support rod (26) rotates and connects to the base of the fixed frame connector (4).

7. The engine test bench nacelle mid-section structure according to claim 6, characterized in that, The opening angle of the left and right hatches is 65°.

8. The engine test bench nacelle mid-section structure according to claim 7, characterized in that, The outer skin (2) includes an upper skin (16) and a lower skin (17). The upper skin (16) covers the outside of the upper partition (7), and a maintenance cover (30) is provided on the upper skin (16). The upper skin (16) is fixedly installed by the upper partition (7) and the upper cover connector (11). The lower skin (17) covers the outside of the lower partition (9). The lower skin (17) adopts a honeycomb sandwich structure (31) and has a skin bulge (32) at the feathering pump. The lower skin (17) is fixedly installed by the lower partition (9) and the partition connector (10).

9. The engine test bench nacelle mid-section structure according to claim 8, characterized in that, The lower skin (17) is provided with an oil radiator exhaust pipe damper opening.

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