Paddle structure aeroelasticity experimental simulation device with adjustable paddle spacing

Abstract

The invention relates to a propeller wing structure aeroelasticity experimental simulation device with an adjustable propeller wing spacing. The device comprises an engine bracket, an engine, a pitching bearing seat, a yawing bearing seat, a first nacelle beam, a yawing fixing seat, a pitching spring piece, a yawing spring piece, a pitching spring support, a balancing weight, a third nacelle beam, a hanging frame, a propeller, a deep groove ball bearing and a universal ball bolt. The device has the advantages that the distance between the propeller plane and the front edge of the wing can be adjusted by adjusting the installation position of the hanging frame sliding block on the third nacelle beam, and then the influence of the distance between the propeller plane and the front end of the wing on the downward washing effect is analyzed. The length of the propeller-pod pylon can be adjusted and controlled by adjusting the butt joint hole positions of the bottom end of the pylon beam and the upper end of the pylon beam, and then the influence of the length of the pod pylon on the aeroelastic stability of the propeller-pod-wing system is analyzed.

Description

Technical Field

[0001] This invention belongs to the technical field, and specifically relates to an aeroelasticity experimental simulation device for a rotor structure with adjustable rotor spacing. Background Technology

[0002] In recent years, the low-altitude economy has received widespread attention. To achieve vertical / short takeoff and landing (VTOL) and meet the fuel and noise reduction goals set forth in Flight Path 2050 and other guidelines, some eVTOL designs employ a propeller-pod-wing propulsion system. However, the combination of a high-aspect-ratio flexible wing and a propeller propulsion system not only introduces rotational flutter but also makes the torsional / bending coupling of the wing under aerodynamic loads more pronounced, potentially leading to static divergence and further amplifying the risk of aeroelastic instability. Therefore, research on the dynamic and static aeroelastic stability of the propeller-pod-wing propulsion system is essential.

[0003] The layout, number, and interaction between the propeller slipstream and the wing surface of the propulsion system profoundly alter the unsteady flow field around the wing and the aerodynamic loads on the structure. On one hand, the slipstream effect can induce aeroelastic instability phenomena such as wing flutter and divergence. Especially under high thrust conditions, the dynamic inflow generated by the propeller and the wing surface vibration can form complex feedback loops, thus affecting structural fatigue life and flight safety. On the other hand, different layouts lead to differences in the aerodynamic efficiency, handling qualities, and stability of the aircraft. Therefore, understanding the impact of different propulsion system layouts (such as the distance between the propeller plane and the wing leading edge) on the aeroelastic stability and overall flight performance of the rotor-wing system is crucial for the overall design, safety boundary delineation, and control law optimization of the aircraft.

[0004] Chinese Patent Publication No. CN104890899B discloses a rotating flutter simulation device that enables adjustable pitch / yaw stiffness, pivot point variation, and advance ratio parameters. Chinese Patent Publication No. 115465473B discloses a rotating flutter simulation device for turboprop aircraft, which has been optimized to accommodate variable parameter studies of the propeller in a windmill-like state. Chinese Patent Publication No. CN120293469A discloses a precession simulation device for propeller flutter wind tunnel testing, enabling adjustable pitch / yaw stiffness, nacelle rotating mass moment of inertia, nacelle weight, and center of mass position parameters. However, with the rapid development of aircraft dynamic layout theory, the above patents have not yet achieved adjustable parameters affecting aeroelastic stability.

[0005] In addition, both the aforementioned rotating flutter simulation device and the turboprop aircraft rotating flutter simulation device are directly fixed to the bottom of the wing beam via a pylon beam. The nacelle beam is a segmented bolted connection structure, which cannot flexibly adjust the installation height and horizontal position, and has a weak ability to adapt to different wind tunnel test scenarios. The spiral precession simulation device used for spiral flutter wind tunnel testing is fixed to the wing via a nacelle cage and bolted to it. It relies on a specific wing structure size and is difficult to adapt to the rapid replacement of different types of wind tunnel test models (such as the installation layout of different power systems of fixed-wing aircraft). Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide an experimental simulation device for the aeroelasticity of a rotor structure with adjustable rotor spacing.

[0007] To achieve the above objectives, the aeroelasticity experimental simulation device for an adjustable rotor structure provided by the present invention includes an engine bracket, an engine, a pitch bearing housing, a yaw bearing housing, a first nacelle beam, a yaw fixing seat, a pitch spring plate, a yaw spring plate, a pitch spring support, a counterweight, a third nacelle beam, a mounting bracket, a propeller, a deep groove ball bearing, and universal ball bolts; wherein, the first nacelle beam includes a head and a tail of the first nacelle beam connected end-to-end by transverse bolts; the rear top and bottom surfaces of the tail of the first nacelle beam are respectively recessed inward to form an upper groove and a lower groove, and a vertical circular hole is formed in the middle of the junction between the rear end of the head of the first nacelle beam and the front end of the tail of the first nacelle beam, and at the same time, the junction... Each side has a vertical blind hole; a deep groove ball bearing is horizontally installed in the vertical hole; a universal ball bolt is installed in each vertical blind hole; the yaw bearing housing is a U-shaped plate structure with a vertical cylinder in the middle of the bottom surface, and grooves corresponding to the universal ball bolts are formed on the outer part of the bottom surface. The cylinders are positioned with openings at the front and rear ends on the top surface of the front of the first nacelle beam and the top surface of the head of the first nacelle beam, and the middle of the vertical cylinder passes through the central hole of the deep groove ball bearing on the first nacelle beam; the yaw fixing seat consists of a top plate and a support column connected to the bottom surface of the top plate. The top plate is installed on the top surface of the lower groove at the rear of the first nacelle beam; the two ends of the yaw spring are respectively connected to the vertical... The lower end of the straight cylindrical column and the lower end of the support column of the yaw fixed seat; the front end of the third nacelle beam is connected to the rear end of the tail of the first nacelle beam, and the top surface is recessed inward to form a groove; the pylon includes a pylon slider, the bottom end of the pylon beam and the upper end of the pylon beam; wherein the pylon slider is fixed in the groove of the third nacelle beam in a position that can be adjusted back and forth; the lower end of the bottom end of the pylon beam is fixed to the top surface of the pylon slider; the upper part is inserted into and fixed to the lower inner part of the upper end of the pylon beam; the pitch bearing seat is an inverted U-shaped plate structure, which is snapped and fixed on the yaw bearing seat, and the two lower ends are in contact with the two upper ends of the yaw bearing seat; a corresponding circular hole is formed in the middle of the two joints of the pitch bearing seat and the yaw bearing seat, and two deep groove ball bearings are installed vertically in a coaxial manner. The engine bracket includes a rectangular frame, a tail rod, and two cam shafts. The rectangular frame is horizontally positioned within the space enclosed by the pitch bearing housing and the yaw bearing housing. The inner ends of the two cam shafts are respectively connected to the middle of the two sides of the rectangular frame, and their middle parts are respectively fixed through the central holes of two deep groove ball bearings on the yaw bearing housing. The tail rod is horizontally positioned, with its front end fixed to the middle of the rear end face of the rectangular frame. The engine is positioned inside the rectangular frame, with its output shaft located at the front end and passing through the front end face of the rectangular frame before connecting to the central shaft of the propeller. The lower part of the pitch spring support is fitted onto the middle of the tail rod. The two ends of the pitch spring plate are respectively fixed to the middle of the top surface of the pitch bearing housing and the upper end of the pitch spring support. The counterweight is fitted onto the rear of the tail rod.

[0008] When the length of the third nacelle beam is insufficient or the structural strength is reduced due to too many openings, thus failing to meet the experimental requirements, the aeroelasticity experimental simulation device for the rotor structure with adjustable rotor spacing also includes at least one second nacelle beam connected between the first and third nacelle beams.

[0009] Multiple fixing holes are formed at intervals along the front-to-back direction on both sides of the third nacelle beam. The mounting block slider is fixed in the appropriate position by bolts passing through different fixing holes.

[0010] A longitudinal protrusion is provided in the middle of the top surface of the pitch bearing housing; one end of the pitch spring plate is fixed to the longitudinal protrusion with bolts together with the pitch spring plate pad.

[0011] The bottom end of the hanging beam consists of a base plate and a diagonal insert rod fixed to the top surface of the base plate; the upper end of the hanging beam consists of a top plate and a diagonal sleeve fixed to the bottom surface of the top plate, with the diagonal insert rod inserted and fixed inside the diagonal sleeve.

[0012] Multiple screw holes are formed at intervals along the length direction on two opposite sides of the bottom and top ends of the bracket beam, and the length of the bracket is adjusted by using bolts passing through different screw holes.

[0013] Multiple screw holes are formed at intervals along the front-rear direction on the partition plate between the upper and lower grooves at the tail of the first nacelle beam. The setting position of the yaw fixing seat is adjusted by using bolts to pass through the different screw holes on the top plate of the yaw fixing seat and the partition plate.

[0014] The aeroelasticity experimental simulation device for rotor structure with adjustable rotor pitch provided by this invention has the following beneficial effects:

[0015] 1. Adjustable distance between propeller plane and wing leading edge: By adjusting the mounting position of the pylon slider on the third nacelle beam, the distance between the propeller plane and the wing leading edge can be adjusted, allowing for analysis of the influence of this distance on the downwash effect. This function can also be used to study the impact of the pod's chordal mounting position on the aeroelastic stability of the propeller-pod-wing system.

[0016] 2. Adjustable length of the pylon: By adjusting the docking holes at the bottom and top of the pylon beam, the length of the "propeller-pod" pylon can be adjusted, and the influence of the pod pylon length on the aeroelastic stability of the "propeller-pod-wing" system can be analyzed.

[0017] 3. Adjustable yaw / pitch stiffness: Based on the stiffness value required for the experiment, the spring sheet of the corresponding size is calculated according to the material mechanics calculation formula. Then, the spring sheet at the yaw / pitch position is disassembled and replaced to achieve different yaw / pitch stiffness effects.

[0018] 4. Adjustable speed / forward ratio: This can be achieved by adjusting the engine speed or replacing propeller components. Attached Figure Description

[0019] Figure 1 A three-dimensional view of the aeroelasticity experimental simulation device for the adjustable blade spacing provided by the present invention.

[0020] Figure 2 This is a three-dimensional view of the hanging bracket in this invention.

[0021] Figure 3 This is an assembly diagram of the component that transmits motion in the yaw direction in this invention.

[0022] Figure 4 This is a schematic diagram of the exploded structure of the first nacelle beam in this invention. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0024] like Figures 1-4As shown, the aeroelasticity experimental simulation device for an adjustable rotor structure provided by the present invention includes an engine bracket 1, an engine 2, a pitch bearing housing 3, a yaw bearing housing 4, a first nacelle beam, a yaw fixing seat 7, a pitch spring plate 9, a yaw spring plate 10, a pitch spring support 11, a counterweight 12, a third nacelle beam 13, a mounting bracket, a propeller 17, a deep groove ball bearing 18, and a universal ball bolt 19; wherein, the first nacelle beam includes a first nacelle beam head 5 and a first nacelle beam tail 6 connected end to end by transverse bolts; the rear top surface and bottom surface of the first nacelle beam tail 6 are respectively recessed inward to form an upper groove and a lower groove, and the middle part of the connection between the rear end of the first nacelle beam head 5 and the front end of the first nacelle beam tail 6 is... A vertical circular hole is formed, and two vertical blind holes are formed on both sides of the joint. A deep groove ball bearing 18 is horizontally installed in the vertical circular hole to reduce frictional interference during yaw displacement transmission. A universal ball bolt 19 is installed in each vertical blind hole to reduce frictional interference during yaw displacement transmission. The yaw bearing seat 4 has a U-shaped plate structure with a vertical cylinder in the middle of the bottom surface. A groove corresponding to the universal ball bolt 19 is formed on the outer part of the bottom surface. The groove is set on the top surface of the front part of the tail 6 of the first nacelle beam and the top surface of the head 5 of the first nacelle beam with the openings located at the front and rear ends. The middle part of the vertical cylinder passes through the center hole of the deep groove ball bearing 18 on the first nacelle beam. The yaw fixing seat 7 is formed from the top. The system consists of a plate and a support column connected to the bottom surface of the top plate. The top plate is installed on the top surface of the lower groove of the tail section 6 of the first nacelle beam. The two ends of the yaw spring plate 10 are respectively connected to the lower end of the vertical cylinder of the yaw bearing seat 4 and the lower end of the support column of the yaw fixing seat 7. The front end of the third nacelle beam 13 is connected to the rear end of the tail section 6 of the first nacelle beam, and the top surface is recessed inward to form a groove. The pylon includes a pylon slider 14, a pylon bottom end 15, and a pylon upper end 16. The pylon slider 14 is fixed in the groove of the third nacelle beam 13 in a position that can be adjusted forward and backward. The lower end of the pylon bottom end 15 is fixed to the top surface of the pylon slider 14. The upper part is inserted into and fixed to the lower inner part of the pylon upper end 16. The pitch bearing seat 3 is an inverted U-shaped plate. The structure is fastened and fixed to the yaw bearing seat 4, with its two lower ends contacting the two upper ends of the yaw bearing seat 4; a corresponding circular hole is formed in the middle of the two joints of the pitch bearing seat 3 and the yaw bearing seat 4, and two deep groove ball bearings 18 are coaxially and vertically installed in the two circular holes to reduce frictional interference during pitch displacement transmission; the engine bracket 1 includes a rectangular frame, a tail rod, and two cam shafts; the rectangular frame is horizontally set in the space enclosed by the pitch bearing seat 3 and the yaw bearing seat 4; the inner ends of the two cam shafts are respectively connected to the middle of the two sides of the rectangular frame, and the middle parts are respectively fixed through the center holes of the two deep groove ball bearings 18 on the yaw bearing seat 4; the tail rod is horizontally set, and the front end is fixed to the middle of the rear end face of the rectangular frame;The engine 2 is housed within the interior space of a rectangular frame, with its output shaft located at the front end, passing through the front face of the rectangular frame and connecting to the central shaft of the propeller 17. The lower part of the pitch spring support 11 is fitted onto the middle of the tail rod. The two ends of the pitch spring plate 9 are respectively fixed to the middle of the top surface of the pitch bearing seat 3 and the upper end of the pitch spring support 11. The counterweight 12 is fitted onto the rear of the tail rod.

[0025] When the length of the third nacelle beam 13 is insufficient or the structural strength is reduced due to too many openings, thus failing to meet the experimental requirements, the aeroelasticity experimental simulation device for the rotor structure with adjustable rotor pitch provided by the present invention further includes at least one second nacelle beam connected between the first nacelle beam and the third nacelle beam 13.

[0026] Multiple fixing holes are formed at intervals along the front-rear direction on both sides of the third nacelle beam 13. The mounting block 14 is fixed in a suitable position by bolts passing through different fixing holes, so that the position of the mounting block 14 is adjustable to match the distance between the propeller plane and the leading edge of the wing required by the experiment, thereby realizing the function of analyzing the influence of nacelle length on aeroelasticity.

[0027] A longitudinal protrusion is provided in the middle of the top surface of the pitch bearing seat 3; one end of the pitch spring plate 9 is fixed to the longitudinal protrusion along with the pitch spring plate pad 8 by bolts, which can further ensure the accuracy of the experiment.

[0028] The bottom end 15 of the hanging beam is composed of a bottom plate and an inclined rod fixed to the top surface of the bottom plate at the lower end; the upper end 16 of the hanging beam is composed of a top plate and an inclined sleeve fixed to the bottom surface of the top plate at the upper end, with the inclined rod inserted and fixed inside the inclined sleeve.

[0029] Multiple screw holes are formed at intervals along the length direction on two opposite sides of the bottom end 15 and the top end 16 of the bracket beam. The length of the bracket is adjusted by using bolts through different screw holes to meet different experimental requirements, thereby realizing the function of analyzing the influence of the bracket length on aeroelasticity.

[0030] Multiple screw holes are formed at intervals along the front-rear direction on the partition plate between the upper and lower grooves of the tail section 6 of the first short nacelle beam. The setting position of the yaw fixing seat 7 is adjusted by using bolts to pass through the different screw holes on the top plate and the partition plate of the yaw fixing seat 7 to match the size of the yaw spring plate 10 required for the experiment.

[0031] The working principle of the aeroelasticity experimental simulation device for the adjustable blade pitch provided by this invention is described below:

[0032] When this device is needed to conduct aeroelasticity experiments on propeller structures, the user can use bolts to fix the top plate on the upper end 16 of the device's mounting beam to the lower end of any rib, provided that the structural strength of the upper rib of the wing is sufficient to support the mounting of this device, based on the required simulated propeller engine installation position.

[0033] When engine 2 is started, propeller 17 operates. As propeller 17 rotates at high speed, the incoming airflow causes it to deviate in both the pitch and yaw directions. The pitch deviation is transmitted to pitch spring 9 via engine bracket 1 and pitch spring support 11, causing pitch spring 9 to deform. The yaw deviation is transmitted to yaw spring 10 via engine bracket 1 and yaw bearing seat 4, causing yaw spring 10 to deform. Therefore, pitch spring 9 and yaw spring 10 provide stiffness in the pitch direction (i.e., pitch stiffness) and yaw direction (i.e., yaw stiffness), respectively. The stiffness can be adjusted by the material of the spring and the effective dimensions (length, width, thickness) of the spring, specifically determined by the user's actual needs.

Claims

1. An aeroelasticity experimental simulation device for a rotor structure with adjustable rotor-wing pitch, characterized in that: The device includes an engine bracket (1), an engine (2), a pitch bearing housing (3), a yaw bearing housing (4), a first nacelle beam, a yaw fixing seat (7), a pitch spring plate (9), a yaw spring plate (10), a pitch spring support (11), a counterweight (12), a third nacelle beam (13), a mounting bracket, a propeller (17), a deep groove ball bearing (18), and a universal ball bolt (19); wherein, the first nacelle beam includes a first nacelle beam head (5) and a first nacelle beam tail (6) connected end to end by transverse bolts; the rear top surface and bottom surface of the first nacelle beam tail (6) are respectively recessed inward to form an upper groove and a lower groove, and the rear end of the first nacelle beam head (5) and the front end ... A vertical circular hole is formed in the middle of the joint, and a vertical blind hole is formed on each side of the joint; a deep groove ball bearing (18) is horizontally installed in the vertical circular hole; a universal ball bolt (19) is set in each vertical blind hole; the yaw bearing seat (4) is a U-shaped plate structure, with a vertical cylinder in the middle of the bottom surface, and a groove corresponding to the universal ball bolt (19) is formed on the outer part of the bottom surface. It is set on the front top surface of the tail (6) of the first nacelle beam and the top surface of the head (5) of the first nacelle beam with the opening located at the front and rear ends. The middle part of the vertical cylinder passes through the center hole of the deep groove ball bearing (18) set on the first nacelle beam; the yaw fixing seat (7) is composed of a top plate and a support column connected to the bottom surface of the top plate. The yaw spring plate (10) is installed on the top surface of the lower groove of the tail section (6) of the first nacelle beam; the two ends of the yaw spring plate (10) are respectively connected to the lower end of the vertical cylinder of the yaw bearing seat (4) and the lower end of the support column of the yaw fixing seat (7); the front end of the third nacelle beam (13) is connected to the rear end of the tail section (6) of the first nacelle beam, and the top surface is recessed inward to form a groove; the pylon includes a pylon slider (14), a pylon bottom end (15) and a pylon upper end (16); wherein the pylon slider (14) is fixed in the groove of the third nacelle beam (13) in a position adjustable front and back; the lower end of the pylon bottom end (15) is fixed on the top surface of the pylon slider (14); the upper part is inserted into and fixed in the lower part of the pylon upper end (16); the pitch bearing seat (3) is an inverted The U-shaped plate structure is fastened and fixed on the yaw bearing seat (4), and the two lower ends are in contact with the two upper ends of the yaw bearing seat (4); a corresponding round hole is formed in the middle of the two joints of the pitch bearing seat (3) and the yaw bearing seat (4), and two deep groove ball bearings (18) are installed vertically in the two round holes in a coaxial manner; the engine bracket (1) includes a rectangular frame, a tail rod and two cam shafts; the rectangular frame is horizontally set in the space enclosed by the pitch bearing seat (3) and the yaw bearing seat (4); the inner ends of the two cam shafts are respectively connected to the middle of the two sides of the rectangular frame and the middle parts are respectively fixed through the center holes of the two deep groove ball bearings (18) on the yaw bearing seat (4); the tail rod is horizontally set and the front end is fixed in the middle of the rear end face of the rectangular frame;The engine (2) is housed within the rectangular frame, with its output shaft located at the front end and extending through the front face of the rectangular frame before connecting to the central shaft of the propeller (17). The lower part of the pitch spring support (11) is fitted onto the middle of the tail rod. The two ends of the pitch spring plate (9) are fixed to the middle of the top surface of the pitch bearing seat (3) and the upper end of the pitch spring support (11), respectively. The counterweight (12) is fitted onto the rear of the tail rod.

2. The aeroelasticity experimental simulation device for an adjustable blade spacing blade structure according to claim 1, characterized in that: When the length of the third nacelle beam (13) is insufficient or the structural strength is reduced due to too many openings and thus cannot meet the experimental requirements, the aeroelasticity experimental simulation device of the blade structure with adjustable blade spacing also includes at least one second nacelle beam connected between the first nacelle beam and the third nacelle beam (13).

3. The aeroelasticity experimental simulation device for an adjustable blade spacing blade structure according to claim 1, characterized in that: Multiple fixing holes are formed at intervals along the front-rear direction on both sides of the third nacelle beam (13). The mounting block slider (14) is fixed in a suitable position by means of bolts passing through different fixing holes.

4. The aeroelasticity experimental simulation device for an adjustable blade spacing blade structure according to claim 1, characterized in that: The pitch bearing housing (3) has a longitudinal protrusion in the middle of its top surface; one end of the pitch spring plate (9) is fixed to the longitudinal protrusion together with the pitch spring plate pad (8) by bolts.

5. The aeroelasticity experimental simulation device for an adjustable blade spacing blade structure according to claim 1, characterized in that: The bottom end (15) of the hanging beam is composed of a bottom plate and an inclined rod fixed to the top surface of the bottom plate; the upper end (16) of the hanging beam is composed of a top plate and an inclined sleeve fixed to the bottom surface of the top plate, with the inclined rod inserted and fixed inside the inclined sleeve.

6. The aeroelasticity experimental simulation device for an adjustable blade spacing blade structure according to claim 1, characterized in that: Multiple screw holes are formed at intervals along the length direction on two opposite sides of the bottom end (15) and top end (16) of the hanging beam, and the length of the hanging beam is adjusted by using bolts to pass through different screw holes.

7. The aeroelasticity experimental simulation device for an adjustable blade spacing blade structure according to claim 1, characterized in that: Multiple screw holes are formed at intervals along the front-rear direction on the partition between the upper and lower grooves of the tail section (6) of the first short nacelle beam. The setting position of the yaw fixing seat (7) is adjusted by using bolts to pass through the top plate of the yaw fixing seat (7) and different screw holes on the partition.

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