An integrated ducted fan test bench

Abstract

The present invention discloses an integrated ducted fan test bench, which relates to the technical field of test benches. The driving element and the tilting module are both installed on the lower body, and the output shaft of the driving element is connected to the input shaft of the speed-changing element. The output shaft of the speed-changing element is connected to the rotor system through a rotating main shaft. A torque and speed measuring instrument is installed on the outer periphery of the rotating main shaft. A connecting frame is installed at the upper end of the tilting module. The middle weighing element and the outer weighing element are both installed on the connecting frame. A first upper cover plate is installed at the upper end of the outer weighing element. The duct body is installed on the first upper cover plate. The outer weighing element is arranged around the outer periphery of the middle weighing element, and the upper end of the middle weighing element passes through the first upper cover plate and is connected to the rotor system. The present invention can separately measure various aerodynamic data of the duct body and the rotor system at the same time, has a high integration degree, greatly reduces the test cost, and improves the test efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of test benches, and particularly to an integrated ducted fan test bench. Background Art

[0002] Compared with rotorcraft that can also achieve vertical takeoff and landing, in ducted fan aircraft, the blades are located inside the duct, making it less likely to cause injury accidents. When flying close to the ground, it is very safe and not easily damaged by external objects such as branches or enemy fire, so its safety is better. At the same time, because the blades are located inside the duct, the unique acoustic shielding effect generated by the duct's wrapping of the blades effectively reduces the sound energy emission intensity of the blades. In particular, the thickness noise in the plane of the blade disk is significantly reduced. In addition, due to the induction of the blades, the oncoming flow velocity at the leading edge of the duct inlet increases greatly, resulting in a flow-around phenomenon, thus forming a large low-pressure area at the duct lip. As a result, the duct itself can provide a considerable part of the pulling force, that is, additional lift, and the presence of the duct inhibits the tip vortices of the blades, improving the state of the airflow below the blade disk, increasing the outflow area, and further reducing the energy loss of the entire system. Compared with a single rotor of the same blade disk size, it will generate greater thrust under the condition of the same power consumption. Therefore, ducted fan aircraft generally have higher propulsion efficiency than rotorcraft.

[0003] The core component of a ducted fan aircraft is its power unit - the ducted fan, which generally consists of two parts (the outer duct body and the rotor system inside the duct body). Traditional test benches can only measure the aerodynamic data of the ducted fan unit as a whole, which is suitable for application scenarios such as engineering applications that focus on overall performance. However, for scientific research, the proportion of the aerodynamic forces of the duct body and the rotor system, as well as the change trends of both and the mutual interference mechanism between them when the parameters change, need to be particularly concerned. In addition, there are many parameters of the ducted fan, such as rotor speed, total pitch of rotor blades, overall inclination of the ducted fan, etc. Traditional ducted fan tests can only be carried out around one or two parameters on one test bench. Therefore, in traditional ducted fan tests, multiple test benches need to be designed for one test to carry out tests in multiple test states, which not only increases the test cost but also reduces the test efficiency. Summary of the Invention

[0004] The purpose of the present invention is to provide an integrated ducted fan test bench to solve the problems existing in the above-mentioned prior art, and to achieve simultaneous and separate measurement of the aerodynamic data of the duct body and the rotor system, with high integration, greatly reducing the test cost and improving the test efficiency.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides an integrated ducted fan test bench, which includes a lower body, a driving element, a speed-changing element, a tilting module, an intermediate weighing element, an outer peripheral weighing element, a duct body and a rotor system. The driving element and the tilting module are both installed on the lower body, and the output shaft of the driving element is connected to the input shaft of the speed-changing element. The output shaft of the speed-changing element is connected to the rotor system through a rotating main shaft. A torque and speed measuring instrument is installed on the outer periphery of the rotating main shaft. A connecting frame is installed at the upper end of the tilting module. The intermediate weighing element and the outer peripheral weighing element are both installed on the connecting frame. A first upper cover plate is installed at the upper end of the outer peripheral weighing element. The duct body is installed on the first upper cover plate. The outer peripheral weighing element is arranged around the outer periphery of the intermediate weighing element, and the upper end of the intermediate weighing element passes through the first upper cover plate and is connected to the rotor system.

[0007] Preferably, the tilting module includes a rocker, two tilting hydraulic struts and two tilting rocker arms. The rocker is movably installed at the upper end of the lower body. The upper end of the rocker is connected to the lower end of the connecting frame. The two tilting hydraulic struts are symmetrically installed on both sides of the rocker. The lower end of the tilting hydraulic strut is rotatably installed at the upper end of the lower body. The upper end of each tilting hydraulic strut is correspondingly rotatably connected to one end of a tilting rocker arm. The other end of each tilting rocker arm is installed at the upper end of the side wall of the rocker.

[0008] Preferably, the speed-changing element is located inside the rocker.

[0009] Preferably, the tilting module further includes two middle body screws. Two limit plates are symmetrically installed at the upper end of the lower body. The two limit plates form a middle body. The line connecting the two limit plates is perpendicular to the line connecting the two tilting hydraulic struts. The two middle body screws are respectively arranged close to the two tilting hydraulic struts. The two ends of the middle body screw are respectively installed at the upper ends of the two limit plates.

[0010] Preferably, the connecting frame includes a trapezoidal frame and a torque frame. The longitudinal section of the trapezoidal frame is trapezoidal. The lower end of the trapezoidal frame is installed at the upper end of the rocker. The upper end of the trapezoidal frame is connected to the lower end of the torque frame. The upper end of the torque frame is connected to the first upper cover plate. The longitudinal section of the torque frame is rectangular.

[0011] Preferably, a plurality of duct struts are installed at the upper end of the first upper cover plate. The plurality of duct struts are arranged around the outer periphery of the duct body. The upper ends of the duct struts are installed on the outer wall of the duct body. The duct body is in the shape of a hollow cylinder.

[0012] Preferably, a second upper cover plate is provided at the upper end of the intermediate weighing element. The lower end of the rotor system is installed on the second upper cover plate.

[0013] Preferably, the rotor system includes variable pitch hydraulic struts, sliding sleeve fork ears, moving rings, torque arms, variable pitch tie rods and blade joints. A plurality of variable pitch hydraulic struts are arranged around the rotating main shaft. The lower ends of the variable pitch hydraulic struts are installed on the second upper cover plate. The upper ends of the variable pitch hydraulic struts are connected to the ends of the sliding sleeve fork ears. Both the sliding sleeve fork ears and the moving rings are slidably sleeved on the outer periphery of the rotating main shaft. The upper end of the sliding sleeve fork ear is connected to the lower end of the moving ring. A plurality of variable pitch tie rods are arranged around the rotating main shaft. The lower ends of the variable pitch tie rods are installed on the moving ring. The upper ends of the variable pitch tie rods are connected to the blade joints. The blade joints are installed on the rotating main shaft and are used for installing blades. There are a plurality of torque arms, and the torque arms are arranged around the outer periphery of the rotating main shaft and are located between the rotating main shaft and the variable pitch tie rods. The lower ends of the torque arms are installed on the moving ring. The upper ends of the torque arms are connected to the rotating main shaft.

[0014] Preferably, the intermediate weighing element is a cassette balance, and the peripheral weighing element is an annular balance.

[0015] Preferably, the driving element is a motor, and the speed-changing element is a gearbox.

[0016] The present invention has achieved the following technical effects compared with the prior art:

[0017] In the integrated ducted fan test bench provided by the present invention, the driving element and the tilting module are both installed on the lower table body, and the output shaft of the driving element is connected to the input shaft of the speed-changing element. The output shaft of the speed-changing element is connected to the rotor system through a rotating main shaft. The driving element provides power for the rotation of the rotor system. The speed-changing element has multiple different gear ratio output modes, which can solve the extremely high / low speed working conditions that are difficult to cover by large motors. A torque and speed measuring instrument is installed on the outer periphery of the rotating main shaft, which plays a role in real-time monitoring of the rotor speed and torque magnitude. A connecting frame is installed at the upper end of the tilting module, and the intermediate weighing element and the peripheral weighing element are both installed on the connecting frame. The tilting module makes the whole perform forward / backward tilting movements, and at the same time cooperates with the oncoming flow of the wind tunnel to carry out the test and measurement of the forward / backward flight conditions of the ducted fan. The upper end of the peripheral weighing element is provided with a first upper cover plate, and the duct body is installed on the first upper cover plate. Furthermore, the force on the duct body is independently monitored through the peripheral weighing element. The peripheral weighing element is arranged around the outer periphery of the intermediate weighing element, and the upper end of the intermediate weighing element passes through the first upper cover plate and is connected to the rotor system. Furthermore, the six forces of the rotor system are independently measured through the intermediate weighing element. By independently monitoring the real-time data of the aerodynamic forces of the duct body and the rotor system, it provides experimental technical support for the research on the interference mechanism between the rotor and the duct body. The present invention integrates functional modules with multiple parameters such as variable rotor speed, variable total pitch of rotor blades, and forward / backward tilting of the whole ducted fan, with a relatively high overall integration degree, greatly reducing the test cost and improving the test efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 Structural schematic diagram of the integrated ducted fan test bench provided by the present invention;

[0020] Figure 2 is Figure 1 front view of;

[0021] Figure 3 Schematic diagram of the integrated ducted fan test bench provided by the present invention when some parts are hidden;

[0022] Figure 4 Structural schematic diagram of the rotor system in the present invention;

[0023] In the figure: 1 - motor, 2 - lower body, 3 - middle body, 4 - rocker, 5 - tilting hydraulic strut, 6 - tilting rocker arm, 7 - middle body screw, 8 - gearbox, 9 - trapezoidal frame, 10 - torque and speed measuring instrument, 11 - torque frame, 12 - ring balance, 13 - box balance, 14 - first upper cover plate, 15 - ducted strut, 16 - ducted body, 21 - second upper cover plate, 22 - pitch-changing hydraulic strut, 23 - sliding sleeve fork ear, 24 - moving ring, 25 - lower arm, 26 - upper arm, 27 - pitch-changing pull rod, 28 - blade joint. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0025] The purpose of the present invention is to provide an integrated ducted fan test bench to solve the problems existing in the prior art, realize the simultaneous and independent measurement of various aerodynamic data of the ducted body and the rotor system, with high integration, greatly reducing the test cost and improving the test efficiency.

[0026] To make the above objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0027] like Figures 1-4 As shown, the present embodiment provides an integrated ducted fan test bench, including a lower body 2, a driving element, a speed changing element, a tilting module, an intermediate weighing element, a peripheral weighing element, a ducted body 16 and a rotor system, wherein the intermediate weighing element is a box-type balance 13, the peripheral weighing element is a ring-shaped balance 12, the driving element is a motor, the speed changing element is a gearbox 8, the motor 1 and the tilting module are both installed on the lower body 2, and the output shaft of the driving element is connected to the input shaft of the gearbox 8, the output shaft of the gearbox 8 is connected to the rotor system through a rotating main shaft, the motor 1 provides power for the rotation of the rotor system, the gearbox 8 has a plurality of different gear ratio output modes, which can solve the extremely high / low speed conditions that are difficult for large motors to cover, so that it can be used as a reducer to provide extremely low speed output, and can also be used as a speed increaser to increase the limit speed, so that the present embodiment can cover most of the ducted fan test speed requirements; the outer periphery of the rotating main shaft is equipped with a torque speed The measuring instrument 10 serves to monitor the rotor speed and torque in real time. A connecting frame is installed on the upper end of the tilt module, and a box balance 13 and an annular balance 12 are both installed on the connecting frame. The tilt module makes the whole body perform forward / backward tilting action, and at the same time cooperates with the wind tunnel flow to carry out the test of the forward / backward flight condition of the ducted fan. A first upper cover plate 14 is installed on the upper end of the annular balance 12, and the duct body 16 is installed on the first upper cover plate 14. The first upper cover plate 14 also serves as the mounting base plate of the duct body 16, and then the force of the duct body 16 is independently monitored through the annular balance 12. The annular balance 12 is arranged around the outer periphery of the box balance 13, and the upper end of the box balance 13 passes through the first upper cover plate 14 and is connected to the rotor system, and then the six forces of the rotor system are independently measured through the box balance 13. By independently monitoring the real-time data of the aerodynamic force of the duct body 16 and the rotor system, experimental technical support is provided for the research on the interference mechanism between the rotor and the duct body 16. This embodiment integrates functional modules of multiple parameters such as variable rotor speed, variable rotor blade collective pitch, and overall forward / backward tilt of the ducted fan. The overall integration is high, which greatly reduces the test cost and improves the test efficiency.

[0028] Specifically, the tilt module includes a cradle 4, two tilt hydraulic struts 5 and two tilt rocker arms 6. The cradle 4 is movably mounted on the upper end of the lower platform 2. The upper end of the cradle 4 is connected to the lower end of the connecting frame. The two tilt hydraulic struts 5 are symmetrically mounted on both sides of the cradle 4, and the lower ends of the tilt hydraulic struts 5 are rotatably mounted on the upper end of the lower platform 2. The upper end of each tilt hydraulic strut 5 is correspondingly connected to one end of a tilt rocker arm 6, and the other end of each tilt rocker arm 6 is mounted on the upper end of the side wall of the cradle 4. The tilt hydraulic strut 5 is used as an actuating member in the tilting process, and drives the tilt rocker arm 6 to move through its extension and contraction, and finally realizes the tilting of the cradle 4. Through the above design, the cradle 4 can drive the various components installed thereon to perform an overall forward / backward tilting action, thereby turning the ducted fan into a forward or backward flight state, and at the same time, cooperate with the wind tunnel flow to carry out the test test of the forward / backward flight condition of the ducted fan.

[0029] The transmission 8 is located within the swing frame 4.

[0030] The tilting module further includes two middle platform screws 7. At the upper end of the lower platform 2, two limiting plates are symmetrically installed. The two limiting plates form the middle platform 3. The line connecting the two limiting plates is perpendicular to the line connecting the two tilting hydraulic struts 5. The two middle platform screws 7 are respectively arranged close to the two tilting hydraulic struts 5, and both ends of the middle platform screw 7 are respectively installed at the upper ends of the two limiting plates. By arranging the two middle platform screws 7 on both sides of the swing frame 4, while serving as a structural reinforcement for the middle platform 3, it also serves as a limiting mechanism for forward / backward tilting, playing a role in preventing overall overturning.

[0031] The connecting frame includes a trapezoidal frame 9 and a torque frame 11. The longitudinal section of the trapezoidal frame 9 is trapezoidal, and the lower end of the trapezoidal frame 9 is installed on the upper end of the swing frame 4. The upper end of the trapezoidal frame 9 is connected to the lower end of the torque frame 11. The upper end of the torque frame 11 is connected to the first upper cover plate 14. The longitudinal section of the torque frame 11 is rectangular. The trapezoidal frame 9 and the torque frame 11 serve as transition parts between the swing frame 4 and the rotor system / ducted body 16, playing a role in adjusting the height of the ducted fan test unit to a position with better flow field quality in the center of the wind tunnel.

[0032] A plurality of ducted struts 15 are installed at the upper end of the first upper cover plate 14. The plurality of ducted struts 15 are arranged around the outer periphery of the ducted body 16, and the upper ends of the ducted struts 15 are installed on the outer wall of the ducted body 16. The ducted body 16 is in the shape of a hollow cylinder.

[0033] A second upper cover plate 21 is provided at the upper end of the cassette balance 13. The lower end of the rotor system is installed on the second upper cover plate 21.

[0034] The rotor system includes variable pitch hydraulic struts 22, sliding sleeve fork ears 23, moving rings 24, torque arms, variable pitch tie rods 27 and blade joints 28. A plurality of variable pitch hydraulic struts 22 are arranged around the rotating main shaft. The lower ends of the variable pitch hydraulic struts 22 are installed on the second upper cover plate 21. The upper ends of the variable pitch hydraulic struts 22 are connected to the ends of the sliding sleeve fork ears 23. The variable pitch hydraulic struts 22 are driving components. Both the sliding sleeve fork ears 23 and the moving rings 24 are slidably sleeved on the outer periphery of the rotating main shaft. The upper ends of the sliding sleeve fork ears 23 are connected to the lower ends of the moving rings 24. A plurality of variable pitch tie rods 27 are arranged around the rotating main shaft. The lower ends of the variable pitch tie rods 27 are installed on the moving rings 24. The upper ends of the variable pitch tie rods 27 are connected to the blade joints 28. The blade joints 28 are installed on the rotating main shaft, and the blade joints 28 are standard connectors for fixedly installing the blades. There are a plurality of torque arms, and the torque arms are arranged around the outer periphery of the rotating main shaft and are located between the rotating main shaft and the variable pitch tie rods 27. The torque arms include upper arms 26 and lower arms 25. The lower ends of the lower arms 25 are installed on the moving rings 24. The upper ends of the lower arms 25 are connected to the lower ends of the upper arms 26. The upper ends of the upper arms 26 are connected to the rotating main shaft. By driving the sliding sleeve fork ears 23 to slide up and down along the rotating main shaft through the variable pitch hydraulic struts 22, the moving rings 24 are pushed to slide up and down, and finally the variable pitch tie rods 27 are pulled to adjust the angles of the blade joints 28 up and down to achieve the variable pitch movement of the rotor blades.

[0035] The middle of the annular balance 12 is hollowed out, so that the box - type balance 13 can be embedded in the annular balance 12. Their different upper cover plates are independently connected to the rotor system and the duct body 16 respectively. Therefore, although they coincide in height in space, they do not interfere with each other and can independently measure the aerodynamic forces of the rotor system and the duct body 16. At the same time, this layout method also greatly improves the space utilization rate, making the volume of the test bench controlled within the required range.

[0036] In the present invention, specific examples are used to elaborate the principle and implementation manner of the present invention. The descriptions of the above embodiments are only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. An integrated ducted fan test bench, characterized in that: It includes a lower platform body, a driving element, a speed-changing element, a tilting module, an intermediate weighing element, an outer peripheral weighing element, a ducted body and a rotor system. The driving element and the tilting module are both installed on the lower platform body, and the output shaft of the driving element is connected to the input shaft of the speed-changing element. The output shaft of the speed-changing element is connected to the rotor system through a rotating main shaft. A torque and speed measuring instrument is installed on the outer periphery of the rotating main shaft. A connecting frame is installed at the upper end of the tilting module. The intermediate weighing element and the outer peripheral weighing element are both installed on the connecting frame. A first upper cover plate is installed at the upper end of the outer peripheral weighing element. The ducted body is installed on the first upper cover plate, so as to independently monitor the force on the ducted body through the outer peripheral weighing element. The outer peripheral weighing element is arranged around the outer periphery of the intermediate weighing element, and the upper end of the intermediate weighing element passes through the first upper cover plate and is connected to the rotor system, so as to independently measure the six forces of the rotor system through the intermediate weighing element; The tilting module includes a rocker, two tilting hydraulic struts and two tilting rocker arms. The rocker is movably installed at the upper end of the lower platform body. The upper end of the rocker is connected to the lower end of the connecting frame. The two tilting hydraulic struts are symmetrically installed on both sides of the rocker. The lower end of the tilting hydraulic strut is rotatably installed at the upper end of the lower platform body. The upper end of each tilting hydraulic strut is correspondingly rotatably connected to one end of a tilting rocker arm. The other end of each tilting rocker arm is installed at the upper end of the side wall of the rocker, so that the rocker can drive each element installed on it to perform an overall forward / backward tilting action, so that the ducted fan can be rotated into the forward flight or reverse flight state, and at the same time cooperate with the oncoming flow of the wind tunnel to carry out the test of the forward / backward flight conditions of the ducted fan.

2. The integrated ducted fan test bench according to claim 1, characterized in that: The speed-changing element is located inside the rocker.

3. The integrated ducted fan test bench according to claim 1, wherein: The tilting module further includes two intermediate platform body screws. Two limit plates are symmetrically installed at the upper end of the lower platform body. The two limit plates form an intermediate platform body. The line connecting the two limit plates is perpendicular to the line connecting the two tilting hydraulic struts. The two intermediate platform body screws are respectively arranged close to the two tilting hydraulic struts, and both ends of the intermediate platform body screw are installed at the upper ends of the two limit plates.

4. The integrated ducted fan test bench according to claim 1, characterized in that: The connecting frame includes a trapezoidal frame and a torque frame. The longitudinal section of the trapezoidal frame is trapezoidal, and the lower end of the trapezoidal frame is installed at the upper end of the rocker. The upper end of the trapezoidal frame is connected to the lower end of the torque frame. The upper end of the torque frame is connected to the first upper cover plate. The longitudinal section of the torque frame is rectangular.

5. The integrated ducted fan test bench according to claim 1, wherein: A plurality of ducted struts are installed at the upper end of the first upper cover plate. The plurality of ducted struts are arranged around the outer periphery of the ducted body, and the upper ends of the ducted struts are installed on the outer wall of the ducted body. The ducted body is in the shape of a hollow cylinder.

6. The integrated ducted fan test bench according to claim 1, characterized in that: A second upper cover plate is provided at the upper end of the intermediate weighing element. The lower end of the rotor system is installed on the second upper cover plate.

7. The integrated ducted fan test bench according to claim 6, wherein: The rotor system includes variable pitch hydraulic struts, sliding sleeve fork ears, moving rings, torque arms, variable pitch tie rods and blade connectors. A plurality of variable pitch hydraulic struts are arranged around the rotating main shaft. The lower ends of the variable pitch hydraulic struts are installed on the second upper cover plate. The upper ends of the variable pitch hydraulic struts are connected to the ends of the sliding sleeve fork ears. Both the sliding sleeve fork ears and the moving rings are slidably sleeved on the outer periphery of the rotating main shaft. The upper end of the sliding sleeve fork ear is connected to the lower end of the moving ring. A plurality of variable pitch tie rods are arranged around the rotating main shaft. The lower ends of the variable pitch tie rods are installed on the moving ring. The upper ends of the variable pitch tie rods are connected to the blade connectors. The blade connectors are installed on the rotating main shaft and are used for installing blades. There are a plurality of torque arms, and the torque arms are arranged around the outer periphery of the rotating main shaft and are located between the rotating main shaft and the variable pitch tie rods. The lower ends of the torque arms are installed on the moving ring, and the upper ends of the torque arms are connected to the rotating main shaft.

8. The integrated ducted fan test bench according to claim 1, characterized in that: The intermediate weighing element is a cassette scale, and the outer peripheral weighing element is an annular scale.

9. The integrated ducted fan test bench according to claim 1, characterized in that: The driving element is a motor, and the speed-changing element is a gearbox.

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