A high-speed wind tunnel nacelle drag measurement device

Abstract

A high-speed wind tunnel nacelle drag measurement device belongs to the field of special wind tunnel testing technology. This invention solves the problem that existing technologies cannot meet the requirements for measuring the external drag of a nacelle. The invention involves an external balance mounting base connected to the lower wall of the wind tunnel test section, with the external balance mounted on the base. A high-pressure ventilation decoupling device is connected to the external balance mounting base and to the floating end of the external balance. The external balance is connected to a fixed support, which has a ventilation groove. The fixed support is connected to a scaled-down engine mount, which has a ventilation groove that communicates with the ventilation groove of the fixed support. A scaled-down turbofan engine nacelle and a turbine power simulator are connected to the upper end of the scaled-down engine mount. This high-speed wind tunnel nacelle drag measurement device improves the geometric similarity between the simulated turbofan engine nacelle and the mount in the wind tunnel.

Description

Technical Field

[0001] This invention belongs to the field of special wind tunnel testing technology. Specifically, it relates to a high-speed wind tunnel nacelle drag measurement device. Background Technology

[0002] The installation impact of turbofan engines reflects the change in aerodynamic characteristics after installing engine pylons and nacelles in an aircraft's reference configuration. The magnitude of this installation impact is one of the main parameters for evaluating the design quality of turbofan engine pylons and nacelles. In recent decades, the bypass ratio of turbofan engines has gradually increased both domestically and internationally, leading to more severe installation effects. For example, for twin-engine transport aircraft with wing-mounted configurations, the installation drag coefficient of typical high-bypass turbofan engines under cruise conditions reaches 0.0030~0.0050, accounting for approximately 10% of the total aircraft drag—a significant proportion. Therefore, domestic and international aircraft design units consider accurately measuring the installation impact of turbofan engine pylons and nacelles under high-speed conditions a key issue in aircraft-engine integration research. They typically conduct wind tunnel selection tests to optimize engine position and pylon configuration through wind tunnel testing, thereby reducing engine installation drag and improving the transport aircraft's economy under cruise conditions.

[0003] There are few domestic patents related to drag wind tunnel testing of turbofan aircraft engine pylons and nacelle scaled-down models. For example, patent publication number CN114720086A mainly introduces a turbofan engine simulation device, including a pylon, an outer bypass duct rectifier, an inner core component, a high-pressure air supply pipe, a mixer collection port, and a mixed air discharge pipe. The patents do not involve using turbine power simulators to conduct high-speed wind tunnel tests on nacelle and pylon drag. Patent publication number CN207717325U mainly introduces a device for measuring the overflow drag of a turbofan engine nacelle. Its technical features include a tail shield to reduce aerodynamic interference from the throttle cone on the nacelle, focusing on overflow drag measurement, and it does not use a turbine power simulator to simulate the intake and exhaust effects of a turbofan engine. Patent publication number CN118776802A is a static thrust calibration device for a high-speed wind tunnel turbine power simulator, focusing on static thrust calibration of the turbine power simulator under high-speed wind tunnel conditions. Patent publication number CN118067351A is a wind tunnel test method for the drag characteristics of a civil engine nacelle. This method does not include the measurement of pylon drag and does not use a turbine power simulator; instead, it uses a ventilated nacelle to simulate the engine's intake and exhaust effects, making it unsuitable for high-fidelity simulation of both intake and exhaust effects of turbofan engines. Existing technologies and literature mostly use numerical calculation methods to determine nacelle drag.

[0004] The aforementioned publicly disclosed patent technologies introduce turbine power simulator device design, nacelle overflow drag measurement, turbine power simulator calibration, and civil engine nacelle drag test methods, but do not involve turbofan engine racks and nacelle drag measurement devices. In particular, existing technologies are difficult to meet the external drag measurement requirements of engine racks and nacelles under high-speed conditions that are of concern to aircraft design units.

[0005] Therefore, this application proposes a high-speed wind tunnel nacelle drag measurement device to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to address the problem that existing technologies are insufficient for measuring the external drag of nacelles. A brief overview of the invention is provided below to offer 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.

[0007] The technical solution of the present invention:

[0008] A high-speed wind tunnel nacelle drag measurement device includes a high-pressure ventilation decoupling device, an external balance mounting base, an external balance, a fixed support, a scaled-down engine mount, a scaled-down turbofan engine nacelle, and a turbine power simulator. The external balance mounting base is connected to the lower wall panel of the wind tunnel test section. The external balance is mounted on the external balance mounting base. One end of the high-pressure ventilation decoupling device is connected to the external balance mounting base, and the other end of the high-pressure ventilation decoupling device is connected to the floating end of the external balance. The floating end of the external balance is connected to the lower part of the fixed support. The fixed support has a fixed support ventilation groove inside. The upper part of the fixed support is connected to the scaled-down engine mount. The scaled-down engine mount has an engine mount ventilation groove inside. The engine mount ventilation groove communicates with the fixed support ventilation groove. The upper end of the scaled-down engine mount is connected to the scaled-down turbofan engine nacelle and the turbine power simulator, respectively. The fixed support, the scaled-down engine mount, the scaled-down turbofan engine nacelle, and the turbine power simulator are all arranged inside the high-speed wind tunnel.

[0009] Furthermore, the turbofan engine scaled-down nacelle is sequentially fixed with the following components: the turbofan engine scaled-down nacelle outer bypass total temperature and pressure rake, the turbofan engine scaled-down nacelle outer bypass nozzle, the turbofan engine scaled-down nacelle inner total temperature and pressure rake, the turbofan engine scaled-down nacelle inner nozzle, and the turbofan engine scaled-down nacelle lower partition wall.

[0010] Furthermore, the front end of the engine scaling mount is connected to a front cable routing groove cover plate for the fixed support, and the rear end of the engine scaling mount is connected to a rear cable routing groove cover plate for the fixed support. The front cable routing groove cover plate for the fixed support and the front end of the fixed support have a front cable routing groove for the engine mount, and the rear cable routing groove cover plate for the fixed support and the rear end of the fixed support have a rear cable routing groove for the engine mount.

[0011] Furthermore, the fixed abdominal support adopts a swept-back angle design, with a front edge swept-back angle of 56° and a rear edge swept-back angle of 52.5°. The inlet ventilation area of ​​the fixed abdominal support ventilation groove inside the fixed abdominal support is larger than the outlet ventilation area.

[0012] Furthermore, the high-pressure ventilation decoupling device includes an inlet flange, a first internal pressure flexible joint, a connecting straight pipe, a second internal pressure flexible joint, a connecting pipeline, a third internal pressure flexible joint, and an outlet flange. The inlet flange is connected to an external balance mounting base, and the outlet flange is connected to an external balance. The first internal pressure flexible joint, the connecting straight pipe, the second internal pressure flexible joint, the connecting pipeline, and the third internal pressure flexible joint are connected sequentially between the inlet flange and the outlet flange. A first reinforcing rib and a second reinforcing rib are installed at the bends of the connecting pipeline.

[0013] Furthermore, it also includes a backup high-pressure ventilation decoupling device, which has the same structure as the high-pressure ventilation decoupling device. The inlet flange of the backup high-pressure ventilation decoupling device is connected to the external balance mounting base, and the outlet flange of the backup high-pressure ventilation decoupling device is connected to the external balance.

[0014] Furthermore, the external balance is a 5-component balance, which includes a fixed end, a measuring end, a measuring beam, an adapter flange, a temperature protection partition for the measuring beam, and a high-pressure ventilation decoupling device connecting flange. Multiple measuring beams are arranged circumferentially between the fixed end and the measuring end. The fixed end, measuring end, and measuring beams are integrally machined parts. The fixed end is connected to the external balance mounting base. The temperature protection partition for the measuring beam is installed on the measuring end through the adapter flange. The high-pressure ventilation decoupling device connecting flange is connected to the inside of the temperature protection partition for the measuring beam. The high-pressure ventilation decoupling device connecting flange is also provided with a spare high-pressure ventilation decoupling device connecting flange and a wiring channel.

[0015] Furthermore, load and transport protection pins are respectively provided on the fixed end and the measuring end, and the load and transport protection pins are used to lock the measuring end and the fixed end.

[0016] Furthermore, the turbine power simulator includes an intake cone, a central shaft, a fan impeller, a fan casing, an air intake seat, a central body, a turbine impeller, and an exhaust casing. The central shaft is rotatably mounted on the central body. The intake cone is connected to the front end of the central shaft via a central bolt. Multiple fan impellers are evenly distributed around the circumference of the intake cone. The front end of the central body is connected to the fan casing, which is located outside the fan impellers. The rear end of the central shaft is rotatably connected to the turbine impeller. The tail end of the central shaft is connected to the exhaust casing. An air intake seat is installed on the outer ring of the exhaust casing. The air intake seat introduces high-pressure air to drive the turbine impeller to rotate.

[0017] Furthermore, the fan casing is connected to the central body via a front pressure plate, and the central shaft is rotatably connected to the central body via a front bearing and a rear bearing. An outer bearing ring is fitted on the outer side of the rear bearing. The exhaust casing is connected to the central shaft via a key. A grate sealing ring is fitted on the central shaft, and an oil injection ring and a sealing ring are fitted on the grate sealing ring. A front nut and a rear nut are installed on the central shaft. The front nut is arranged inside the intake cone, and the rear nut is arranged inside the exhaust casing. A lead wire cover and a lubricating oil connector are provided on the bleed seat.

[0018] The present invention has the following beneficial effects:

[0019] 1. The high-speed wind tunnel nacelle drag measurement device of the present invention can achieve geometric similarity between the scaled-down nacelle and pylon of a high-speed wind tunnel turbofan engine and the real turbofan engine nacelle and pylon, thereby improving the degree of geometric similarity between the simulated turbofan engine nacelle and pylon in the wind tunnel.

[0020] 2. The high-speed wind tunnel nacelle drag measurement device of the present invention differs from the wind tunnel measurement device for turbofan engine nacelle drag using a snorkel nacelle or ejector nacelle. The present invention designs a turbine power simulator, which realizes the simultaneous simulation of intake and exhaust of turbofan engine with 100% bypass duct exhaust pressure ratio and more than 85% intake flow coefficient, significantly improving the ability to simultaneously simulate the intake and exhaust of turbofan engine in the wind tunnel.

[0021] 3. The high-speed wind tunnel nacelle drag measurement device of the present invention adopts a wind tunnel test method that deducts the static thrust of the turbine power simulator and the fixed belly support drag, thereby improving the drag measurement accuracy of the scaled-down nacelle and pylon of the turbofan engine.

[0022] 4. The high-speed wind tunnel nacelle drag measurement device of the present invention is designed with a large-size external balance with a high-pressure ventilation decoupling device, which significantly reduces the deformation of the scaled-down turbofan engine mount and nacelle in the high-speed wind tunnel.

[0023] 5. The fixed support of the high-speed wind tunnel nacelle drag measurement device of the present invention adopts a swept-back angle design, which effectively reduces the support interference effect of the fixed support on the turbofan engine mount and nacelle drag measurement in the high-speed wind tunnel, and improves the drag measurement accuracy. Attached Figure Description

[0024] Figure 1 This is a schematic cross-sectional view of a high-speed wind tunnel nacelle drag measurement device.

[0025] Figure 2 This is a schematic diagram showing the connection relationship between the fixed belly support, the engine scaled-down mount, and the turbine power simulator.

[0026] Figure 3 This is a rear view of a high-speed wind tunnel nacelle drag measurement device.

[0027] Figure 4 This is a schematic diagram showing the coordination between the engine scaled-down mount and the nacelle drag measurement device.

[0028] Figure 5 This is a schematic diagram of an external balance structure;

[0029] Figure 6 This is a schematic diagram of a high-pressure ventilation decoupling device;

[0030] Figure 7 This is a schematic diagram of a turbine power simulator;

[0031] Figure 8 This is a cross-sectional schematic diagram of a turbine power simulator.

[0032] In the diagram: 1-High-speed wind tunnel, 2-Lower wall panel of wind tunnel test section, 3-High-pressure ventilation decoupling device, 4-Spare high-pressure ventilation decoupling device, 5-External balance mounting base, 6-External balance, 7-Fixed support, 8-Fixed support ventilation slot, 9-Fixed support front wiring channel cover, 10-Fixed support rear wiring channel cover, 11-Engine scaled-down mount, 12-Engine mount ventilation slot, 13-Engine mount front wiring channel, 14-Engine mount rear wiring channel, 15-Turbofan engine scaled-down short 16-Turbine power simulator, 17-Scaled-down turbofan engine nacelle external bypass total temperature and pressure rake, 18-Scaled-down turbofan engine nacelle external bypass nozzle, 19-Scaled-down turbofan engine nacelle internal total temperature and pressure rake, 20-Scaled-down turbofan engine nacelle internal nozzle, 21-Scaled-down turbofan engine nacelle lower partition wall, 300-Second internal pressure flexible section, 301-Intake flange, 302-First internal pressure flexible section, 303-Connecting straight pipe, 305-Connecting pipeline, 306-First reinforcing rib, 3 07-Second reinforcing rib, 308-Third internal pressure flexible joint, 309-Outlet flange, 601-Fixed end, 602-Measuring end, 603-Measuring beam, 604-Transfer flange, 605-Measuring beam temperature protection partition, 606-High-pressure ventilation decoupling device connecting flange, 607-Cable routing channel, 608-Spare high-pressure ventilation decoupling device connecting flange, 609-Load and transportation protection pin, 1601-Inlet cone, 1602-Center bolt, 1603-Center shaft, 16 04-Fan impeller, 1605-Fan casing, 1606-Front pressure plate, 1607-Air intake seat, 1608-Center body, 1609-Sealing ring, 1610-Bearing outer ring, 1611-Turbine impeller, 1612-Lubricating oil connector, 1613-Lead wire cover, 1614-Exhaust casing, 1615-Rear nut, 1616-Flat key, 1617-Rear bearing, 1618-Grate sealing ring, 1619-Oil injection ring, 1620-Front bearing, 1621-Front nut. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0034] The connections mentioned in this invention are divided into fixed connections and detachable connections. Fixed connections (i.e., non-detachable connections) include, but are not limited to, conventional fixed connection methods such as folded connections, riveted connections, adhesive connections, and welded connections. Detachable connections include, but are not limited to, conventional disassembly methods such as threaded connections, snap-fit ​​connections, pin connections, and hinged connections. When a specific connection method is not explicitly defined, it is assumed that at least one existing connection method can always be found to achieve the function, and those skilled in the art can choose according to their needs. For example, a welded connection can be chosen for fixed connections, and a hinged connection can be chosen for detachable connections.

[0035] Example 1, combined with Figures 1-4 This embodiment describes a high-speed wind tunnel nacelle drag measurement device, comprising a high-pressure ventilation decoupling device 3, an external balance mounting base 5, an external balance 6, a fixed support 7, a scaled-down engine mount 11, a scaled-down turbofan engine nacelle 15, and a turbine power simulator 16. The external balance mounting base 5 is connected to the lower wall panel 2 of the wind tunnel test section. The external balance 6 is mounted on the external balance mounting base 5. One end of the high-pressure ventilation decoupling device 3 is connected to the external balance mounting base 5, and the other end of the high-pressure ventilation decoupling device 3 is connected to the floating end of the external balance 6. The floating end of the external balance 6... The moving end is connected to the lower part of the fixed support 7. The fixed support 7 has a fixed support ventilation groove 8 inside. The upper part of the fixed support 7 is connected to the engine scaled-down bracket 11. The engine scaled-down bracket 11 has an engine bracket ventilation groove 12 inside. The engine bracket ventilation groove 12 communicates with the fixed support ventilation groove 8. The upper end of the engine scaled-down bracket 11 is connected to the turbofan engine scaled-down nacelle 15 and the turbine power simulator 16 respectively. The fixed support 7, the engine scaled-down bracket 11, the turbofan engine scaled-down nacelle 15 and the turbine power simulator 16 are all arranged in the high-speed wind tunnel 1.

[0036] High-speed wind tunnel 1 is selected to be carried out in a high-speed wind tunnel with a test section size greater than 2.0 meters. High-speed wind tunnel 1 is a continuous high-speed wind tunnel or a temporary high-speed wind tunnel. The lower wall plate 2 of the wind tunnel test section is selected on the lower wall or side wall of high-speed wind tunnel 1.

[0037] The lower wall panel 2 of the wind tunnel test section is designed with mounting holes. The external balance fixing seat 5 is fixed in the mounting holes. The upper end of the external balance fixing seat 5 is connected to the external balance 6 and designed with a stop. M16 screws and positioning pins are used to achieve fastening. The lower end of the external balance fixing seat 5 is connected to the lower wall panel 2 of the wind tunnel test section through a flange. 40 circumferential M16 screws and positioning pins are used to achieve fastening. The interior of the external balance fixing seat 5 is a hollow structure with an outer diameter of 700mm, an inner diameter of 630mm, a maximum wall thickness of 35mm, and a height of 506mm. The material is high-strength precipitation hardening stainless steel 05Cr17Ni4Cu4Nb.

[0038] The fixed belly support 7, the front cable tray cover 9, and the rear cable tray cover 10 are connected as a whole by a stop and screws to reduce the impact of high-speed airflow on the turbofan engine mount and nacelle drag measurement. The fixed belly support 7 adopts a swept-back design, with a leading edge sweep angle of 56°, a trailing edge sweep angle of 52.5°, and a length of 800mm, and is made of stainless steel. The fixed belly support 7 has a fixed belly support venting groove 8 inside. The design pressure of the fixed belly support venting groove 8 is usually greater than 5.0MPa. The venting cross-section is a runway-shaped structure with a sealing groove. The inlet venting area of ​​the fixed belly support venting groove 8 is 300mm². 2 The outlet ventilation area is 200mm. 2 The inlet ventilation area of ​​the fixed belly support ventilation slot 8 is larger than the outlet ventilation area of ​​the ventilation slot, which helps to reduce pressure loss and significantly minimizes the interference of the fixed belly support 7 of the high-speed wind tunnel 1 on the drag measurement of the turbofan engine mount and nacelle. The materials of the front cable tray cover plate 9 and the rear cable tray cover plate 10 of the fixed belly support are stainless steel 304 or aluminum alloy 7075.

[0039] The engine scale-down mount 11, the front wiring channel 13, and the rear wiring channel 14 are connected as a single unit via stops and screws. It is approximately a 1:27 scale model of a real aircraft engine mount, and the material is high-strength precipitation-hardening stainless steel 05Cr17Ni4Cu4Nb. The engine scale-down mount 11 internally incorporates an engine mount ventilation slot 12. This ventilation slot 12 is designed with a pressure typically greater than 4.0 MPa and a maximum high-pressure airflow rate greater than 1.31 kg / s. Its cross-section is a runway-shaped structure with sealing grooves, and the ventilation section is 200 mm². 2 .

[0040] Example 2, combined with Figures 1-4This embodiment describes a high-speed wind tunnel nacelle drag measurement device. The scaled-down nacelle 15 of the turbofan engine is sequentially fixed with the following components: an external duct total temperature and pressure rake 17, an external duct nozzle 18, an internal duct total temperature and pressure rake 19, an internal nozzle 20, and a lower partition wall 21. Both the external duct nozzle 18 and the lower partition wall 21 are load-bearing components and should be made of materials with high tensile strength and a wide applicable temperature range. In this embodiment, high-strength precipitation-hardening stainless steel 05Cr17Ni4Cu4Nb is used.

[0041] The turbofan engine scaled-down nacelle 15 and the turbofan engine scaled-down nacelle outer bypass nozzle 18 are connected as a whole by pins. It is a scaled-down shape of the real aircraft engine nacelle and outer bypass nozzle at approximately 1:27 scale. The total length is 214mm and the maximum diameter is 139mm. The material of the turbofan engine scaled-down nacelle 15 inlet is aluminum alloy 2A70, and the material of the turbofan engine scaled-down nacelle outer bypass nozzle 18 is high-strength precipitation hardening stainless steel 05Cr17Ni4Cu4Nb.

[0042] The total temperature and pressure rake 17 of the turbofan engine scaled-down nacelle bypass is located after the fan exhaust stator of the turbine power simulator 16 and installed inside the turbofan engine scaled-down nacelle bypass nozzle 18. It consists of a total pressure rake and a total temperature rake. There are six total pressure rakes, each with four total pressure probes. The four total pressure probes are radially distributed according to equal ring area. There are four total temperature rakes, matched and designed in the middle of the total pressure rakes. Each rake has one total temperature probe.

[0043] The turbofan engine scaled-down nacelle outer bypass total temperature and total pressure rake 17 and the turbofan engine scaled-down nacelle inner total temperature and total pressure rake 19 are both composed of multiple sets of total pressure rakes and multiple sets of total temperature rakes. Each total pressure rake is designed with several measuring points along the radial direction, and the measuring points are distributed with equal area between them. Each total temperature rake is a single point, and each total pressure rake and each total temperature rake are distributed at equal angles in the circumferential direction of the flow area.

[0044] Under extreme conditions, the expansion of high-pressure gas in the turbine engine simulator 16 causes the turbine airflow temperature to drop below -60°C. Therefore, the turbine engine scaled-down nacelle nozzle 20 is made of non-metallic material with good heat insulation properties, such as phenolic resin or Teflon. At the same time, heating tape is attached to the surface of the turbofan engine scaled-down nacelle nozzle 20 to prevent condensation caused by the low temperature of the internal gas.

[0045] Example 3, combined with Figure 1 and Figure 5This embodiment describes a high-speed wind tunnel nacelle drag measurement device. The external balance 6 is used to measure the drag of the scaled-down turbofan engine nacelle 15 and the scaled-down engine mount 11. The external balance 6 is a 5-component balance with a near-cylindrical hollow structure, an outer diameter of 620mm, an inner diameter of 340mm, and a total height of 293mm. It is made of high-strength precipitation-hardening stainless steel 05Cr17Ni4Cu4Nb. The external balance 6 has a lift load of 35000N, a drag load of 6500N, a pitch moment of 10000N.m, a yaw moment of 6400N.m, and a roll moment of 35000N.m.

[0046] The fixed end 601, measuring end 602, and measuring beam 603 of the external balance 6 are integrally machined components. Multiple measuring beams 603 are arranged between the fixed end 601 and the measuring end 602. The fixed end 601 is connected to the external balance mounting base 5 via a flange. The transition flange 604 is fixedly connected to the measuring end 602 via a flange. The measuring beam temperature protection plate 605 is connected to the transition flange 604 via a flange. The high-pressure venting decoupling device connecting flange 606 is connected to the inside of the measuring beam temperature protection plate 605. The high-pressure venting decoupling device connecting flange 606 is also equipped with a spare high-pressure venting decoupling device connecting flange 608 and a wiring channel 607. The high-pressure venting decoupling device 3 is connected to the high-pressure venting decoupling device connecting flange 606, and the spare high-pressure venting decoupling device 4 is connected to the spare high-pressure venting decoupling device connecting flange 608.

[0047] The measuring beam 603 consists of four lift elements, two drag elements, and four yaw or roll moment elements. The four lift elements and two drag elements work together to measure the pitch moment load. The four lift elements and two drag elements are in the form of a single-bending beam, and each element has a damping element at its free end to eliminate strain interference from loads other than the measured load. The four yaw or roll moment elements are in the form of tension / compression elements, with damping elements designed at both ends to eliminate strain interference from loads other than the measured load. The load and transport protection pin 609 has six M12 pins used to lock the measuring end 602 and the fixed end 601 of the external balance 6, preventing damage to the external balance 6 during transportation and installation. The central axis of the external balance 6 is the Y-axis, with the Y-axis vertically upward as positive, the X-axis horizontally pointing upstream of the wind tunnel as positive, and the Z-axis conforming to the right-hand rule. The external balance 6 has positive lift on the positive Y-axis, positive thrust on the positive X-axis, and positive lateral force on the positive Z-axis.

[0048] Example 4, combined with Figure 3 and Figure 6This embodiment describes a high-speed wind tunnel nacelle drag measurement device. The high-pressure ventilation decoupling device 3 and the backup high-pressure ventilation decoupling device 4 have the same structure, both consisting of three L-shaped flexible joints connected together. These three L-shaped flexible joints eliminate interference from the high-pressure air supply pipeline to the external balance 6. The inlet flange 301 of both the high-pressure ventilation decoupling device 3 and the backup high-pressure ventilation decoupling device 4 is connected to the external balance mounting base 5, and the outlet flange 309 is connected to the external balance 6. The first internal pressure type... Flexible joint 302, second internal pressure flexible joint 305, and third internal pressure flexible joint 308 have the same structure, with an inner diameter of 70mm, an outer diameter of 137mm, and a length of 175mm. They include a rectifier plate, flange, metal bellows, and cross-shaped noise reduction joint. The metal bellows has an inner diameter of 75mm, an outer diameter of 95mm, a length of 81.6mm, a design pressure of 6.0MPa, and is made of Inconel 718 material. It is designed with 3 layers, each with a wall thickness of 0.22mm. The cross-shaped noise reduction joint is made of 00Ni18Co8Mo5TiAl material. The inlet flange 301 of the high-pressure ventilation decoupling device 3 is fastened to the external balance mounting base 5 along the Z-direction, and the inlet flange of the standby high-pressure ventilation decoupling device 4 is fastened to the external balance mounting base 5 along the -Z-direction. The inlet pipes of the high-pressure ventilation decoupling device 3 and the backup high-pressure ventilation decoupling device 4 are symmetrically fastened to the external balance mounting base 5, which effectively reduces the influence of the gas pressure and gas momentum inside the ventilation decoupling device on the force measurement of the external balance 6.

[0049] A first internal pressure flexible joint 302, a connecting straight pipe 303, a second internal pressure flexible joint 300, a connecting pipe 305, and a third internal pressure flexible joint 308 are sequentially connected between the inlet flange 301 and the outlet flange 309. A first reinforcing rib 306 and a second reinforcing rib 307 are installed at the bend of the connecting pipe 305 to improve the strength of the bend of the connecting pipe 305.

[0050] High-pressure drive gas regulating valves are designed before the high-pressure ventilation decoupling device 3 and the backup high-pressure ventilation decoupling device 4, requiring the ability to control the high-pressure gas mass flow rate with an accuracy of less than 0.5 g / s or to control the speed of the turbine power simulator 16 within 500 rpm. The drag of the engine scaled-down mount 11, the turbofan engine scaled-down nacelle 15, the turbine power simulator 16, and the fixed support 7 are measured by an external balance 6 equipped with the high-pressure ventilation decoupling device 3 and the backup high-pressure ventilation decoupling device 4. After deducting the static thrust of the turbine power simulator 16 and the drag of the fixed support 7, the drag of the engine scaled-down mount 11 and the turbofan engine scaled-down nacelle 15 can be obtained.

[0051] Example 5, combined with Figures 1-3 , Figures 7-8This embodiment describes a high-speed wind tunnel nacelle drag measurement device. The turbine power simulator 16 rotor has a typical structure of single shaft, double support points, one-stage fan, and one-stage turbine. The rotor support method is "0-2-0", that is, the front bearing 1620 is located behind the fan impeller 1604, and the rear bearing 1617 is located in front of the turbine impeller 1611. This support structure has good rigidity and can ensure that the rotor has small deformation and stable operation during operation.

[0052] A central shaft 1603 is rotatably mounted on a central body 1608. An intake cone 1601 is connected to the front end of the central shaft 1603 via a central bolt 1602. Multiple fan impellers 1604 are evenly distributed around the circumference of the intake cone 1601. A fan casing 1605 is connected to the front end of the central body 1608, and the fan casing 1605 is positioned outside the fan impellers 1604. A turbine impeller 1611 is rotatably connected to the rear end of the central shaft 1603. An exhaust casing 1614 is connected to the tail end of the central shaft 1603. An air intake seat 1607 is mounted on the outer ring of the exhaust casing 1614, and the air intake seat 1607 introduces high-pressure air to drive the turbine impeller 1611 to rotate. The fan casing 1605 is connected to the central body 1608 via a front pressure plate 1606. 08 connection, the central shaft 1603 is rotatably connected to the central body 1608 through the front bearing 1620 and the rear bearing 1617. The outer bearing ring 1610 is fitted on the outer side of the rear bearing 1617. The exhaust casing 1614 is keyed to the central shaft 1603 through the flat key 1616. The central shaft 1603 is fitted with a toothed sealing ring 1618. The toothed sealing ring 1618 is fitted with an oil injection ring 1619 and a sealing ring 1609. The central shaft 1603 is equipped with a front nut 1621 and a rear nut 1615. The front nut 1621 is arranged inside the intake cone 1601, and the rear nut 1615 is arranged inside the exhaust casing 1614. The bleed seat 1607 is provided with a lead wire cover 1613 and a lubricating oil connector 1612.

[0053] The front bearing 1620 is designed as the main bearing of the turbine power simulator 16, meaning that the front bearing 1620 bears both the radial load and the axial load of the rotor and adopts an SKF ultra-precision ceramic ball angular contact bearing; the rear bearing 1617 only bears the radial load and also adopts an SKF ultra-precision ceramic ball angular contact bearing.

[0054] A single-axis acceleration vibration sensor is arranged on the outer ring of the fan casing 1605 to monitor the vibration state of the turbine power simulator 16 during operation. The turbine power simulator 16 is equipped with an air intake seat 1607, which introduces high-pressure air into the turbine intake chamber and drives the turbine impeller 1611 to rotate through the turbine guide. The turbine impeller 1611 drives the fan impeller 1604 to rotate synchronously through the central shaft 1603 to achieve air intake. A lead wire cover 1613 is designed at the rear of the air intake seat 1607. The cables of the vibration sensor, bearing temperature sensor, and other sensors of the turbine power simulator 16 converge into the lead wire cover 1613 and are then centrally led to the control system. At the same time, an oil fitting 1612 is installed at the upper end of the air intake seat 1607, through which lubricating oil flows into the bearing lubrication point. The air intake seat 1607 is positioned and installed on the outer ring of the exhaust casing 1614 by a locating pin and locked with bolts.

[0055] The turbine power simulator 16 has a total length of 165.7 mm. The fan impeller 1604 has a blade tip diameter of 106.7 mm. Under atmospheric pressure, the fan impeller 1604 is designed with an inlet flow rate of 1.53 kg / s, a maximum design pressure ratio of 1.55, 19 blades, and is made of titanium alloy TC4. The fan guide vanes have 20 blades made of high-strength precipitation-hardening stainless steel 05Cr17Ni4Cu4Nb. The turbine impeller 1611 has a blade tip diameter of 60.0 mm. The turbine impeller 1611 is designed to drive a gas pressure of 2.2 MPa and a design flow rate of 1.31 kg / s. The design driving gas temperature is 65℃, the design speed is 84,000 rpm, the design output power is approximately 125KW, the rotor has 25 blades made of aluminum alloy 2A70, the turbine guide vanes have 17 blades, and the outlet guide vanes have 24 blades made of high-strength precipitation-hardening stainless steel 05Cr17Ni4Cu4Nb. The central shaft 1603 connects the fan impeller 1604 and the turbine impeller 1611 and is a key load-bearing component. Its operating temperature is within the range of -55℃ to 65℃, and the material selected is high-temperature alloy GH4169. Other metal parts are made of stainless steel 304.

[0056] The fan rotor blades and fan guide vanes pressurize the airflow in the high-speed wind tunnel 1 and then discharge it from the bypass. The high-pressure air is introduced into the turbine guide vanes for expansion and acceleration, driving the turbine impeller 1611 blades to rotate. The turbine impeller 1611 blades are coaxial with the fan impeller 1604. All the work done by the turbine expansion is used to drive the fan impeller 1604. After the high-pressure air expands and does work, it is discharged into the main flow of the high-speed wind tunnel 1 through the exhaust rectifier. The speed vibration and bearing temperature monitoring system is used to measure the fan speed, vibration amount, and bearing temperature of the turbine power simulator 16 in real time. The turbine power simulator 16 is designed to achieve simultaneous simulation of the intake and exhaust of the turbofan engine with 100% bypass exhaust pressure ratio and more than 85% intake flow coefficient.

[0057] This embodiment is merely an exemplary illustration of the present invention and does not limit its scope of protection. Those skilled in the art can make partial changes to it, as long as they do not exceed the spirit and essence of the present invention, they are all within the scope of protection of the present invention.

Claims

1. A high-speed wind tunnel nacelle drag measurement device, characterized in that: The system includes a high-pressure ventilation decoupling device (3), an external balance mounting base (5), an external balance (6), a fixed belly support (7), an engine scaled-down mount (11), a turbofan engine scaled-down nacelle (15), and a turbine power simulator (16). The external balance mounting base (5) is connected to the lower wall panel (2) of the wind tunnel test section. The external balance (6) is mounted on the external balance mounting base (5). One end of the high-pressure ventilation decoupling device (3) is connected to the external balance mounting base (5), and the other end of the high-pressure ventilation decoupling device (3) is connected to the floating end of the external balance (6). The floating end of the external balance (6) is connected to the lower part of the fixed belly support (7). Next, the fixed belly support (7) has a fixed belly support ventilation groove (8) inside. The upper part of the fixed belly support (7) is connected to the engine scaled-down bracket (11). The engine scaled-down bracket (11) has an engine bracket ventilation groove (12) inside. The engine bracket ventilation groove (12) is connected to the fixed belly support ventilation groove (8). The upper end of the engine scaled-down bracket (11) is connected to the turbofan engine scaled-down nacelle (15) and the turbine power simulator (16). The fixed belly support (7), the engine scaled-down bracket (11), the turbofan engine scaled-down nacelle (15) and the turbine power simulator (16) are all arranged in the high-speed wind tunnel (1).

2. The high-speed wind tunnel nacelle drag measurement device according to claim 1, characterized in that: The turbofan engine scaled-down nacelle (15) is sequentially fixed with the following components: turbofan engine scaled-down nacelle outer bypass total temperature and pressure rake (17), turbofan engine scaled-down nacelle outer bypass nozzle (18), turbofan engine scaled-down nacelle inner total temperature and pressure rake (19), turbofan engine scaled-down nacelle inner nozzle (20), and turbofan engine scaled-down nacelle lower partition wall (21).

3. The high-speed wind tunnel nacelle drag measurement device according to claim 2, characterized in that: The front end of the engine scaling bracket (11) is connected to a front cable routing groove cover plate (9) for a fixed support, and the rear end of the engine scaling bracket (11) is connected to a rear cable routing groove cover plate (10) for a fixed support. The front cable routing groove cover plate (9) for a fixed support and the front end of the fixed support (7) have a front cable routing groove (13) for the engine bracket, and the rear cable routing groove cover plate (10) for a fixed support and the rear end of the fixed support (7) have a rear cable routing groove (14) for the engine bracket.

4. The high-speed wind tunnel nacelle drag measurement device according to claim 3, characterized in that: The fixed abdominal support (7) adopts a swept-back angle design. The front edge swept-back angle of the fixed abdominal support (7) is 56° and the rear edge swept-back angle is 52.5°. The inlet ventilation area of ​​the fixed abdominal support ventilation groove (8) inside the fixed abdominal support (7) is larger than the outlet ventilation area.

5. A high-speed wind tunnel nacelle drag measurement device according to claim 1 or 4, characterized in that: The high-pressure ventilation decoupling device (3) includes an inlet flange (301), a first internal pressure flexible joint (302), a connecting straight pipe (303), a second internal pressure flexible joint (300), a connecting pipeline (305), a third internal pressure flexible joint (308), and an outlet flange (309). The inlet flange (301) is connected to the external balance mounting base (5), and the outlet flange (309) is connected to the external balance (6). The first internal pressure flexible joint (302), the connecting straight pipe (303), the second internal pressure flexible joint (300), the connecting pipeline (305), and the third internal pressure flexible joint (308) are connected sequentially between the inlet flange (301) and the outlet flange (309). A first reinforcing rib (306) and a second reinforcing rib (307) are installed at the bend of the connecting pipeline (305).

6. The high-speed wind tunnel nacelle drag measurement device according to claim 5, characterized in that: It also includes a backup high-pressure ventilation decoupling device (4), which has the same structure as the high-pressure ventilation decoupling device (3). The air inlet flange (301) of the backup high-pressure ventilation decoupling device (4) is connected to the external balance mounting base (5), and the air outlet flange (309) of the backup high-pressure ventilation decoupling device (4) is connected to the external balance (6).

7. A high-speed wind tunnel nacelle drag measurement device according to claim 1 or 4, characterized in that: The external balance (6) is a 5-component balance. The external balance (6) includes a fixed end (601), a measuring end (602), a measuring beam (603), a transition flange (604), a temperature protection partition for the measuring beam (605), and a high-pressure ventilation decoupling device connecting flange (606). Multiple measuring beams (603) are arranged circumferentially between the fixed end (601) and the measuring end (602). The fixed end (601), the measuring end (602), and the measuring beams (603) As an integrally machined part, the fixed end (601) is connected to the external balance mounting base (5), the temperature protection partition (605) of the measuring beam is installed on the measuring end (602) through the adapter flange (604), the high pressure ventilation decoupling device connecting flange (606) is connected to the inside of the temperature protection partition (605) of the measuring beam, and the high pressure ventilation decoupling device connecting flange (606) is also provided with a spare high pressure ventilation decoupling device connecting flange (608) and a wiring channel (607).

8. The high-speed wind tunnel nacelle drag measurement device according to claim 7, characterized in that: The fixed end (601) and the measuring end (602) are respectively provided with load and transport protection pins (609), which are used to lock the measuring end (602) and the fixed end (601).

9. A high-speed wind tunnel nacelle drag measurement device according to claim 1 or 4, characterized in that: The turbine power simulator (16) includes an intake cone (1601), a central shaft (1603), a fan impeller (1604), a fan casing (1605), an air intake seat (1607), a central body (1608), a turbine impeller (1611), and an exhaust casing (1614). The central shaft (1603) is rotatably mounted on the central body (1608). The intake cone (1601) is connected to the front end of the central shaft (1603) by a central bolt (1602). The intake cone (1601) is circumferentially distributed with... There are multiple fan impellers (1604), and a fan casing (1605) is connected to the front end of the central body (1608). The fan casing (1605) is arranged outside the fan impellers (1604). A turbine impeller (1611) is rotatably connected to the rear end of the central shaft (1603). An exhaust casing (1614) is connected to the tail end of the central shaft (1603). An air intake seat (1607) is installed on the outer ring of the exhaust casing (1614). The air intake seat (1607) introduces high-pressure air to drive the turbine impeller (1611) to rotate.

10. The high-speed wind tunnel nacelle drag measurement device according to claim 9, characterized in that: The fan housing (1605) is connected to the central body (1608) via a front pressure plate (1606). The central shaft (1603) is rotatably connected to the central body (1608) via a front bearing (1620) and a rear bearing (1617). A bearing outer ring (1610) is fitted on the outer side of the rear bearing (1617). The exhaust housing (1614) is keyed to the central shaft (1603) via a flat key (1616). The central shaft (1603) is fitted with grating teeth. A sealing ring (1618) is fitted with an oil injection ring (1619) and a sealing ring (1609). A front nut (1621) and a rear nut (1615) are installed on the central shaft (1603). The front nut (1621) is arranged inside the intake cone (1601), and the rear nut (1615) is arranged inside the exhaust casing (1614). A lead wire cover (1613) and an oil fitting (1612) are provided on the bleed seat (1607).

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