A simulation mechanism for heave oscillation test of a large-sized aircraft

Abstract

A simulation mechanism for heaving oscillation test of a large-sized aircraft, belonging to the field of aircraft tests, comprises a turntable base, a large-sized aircraft, a support unit, a motion unit and a fixing unit. The large-sized aircraft is installed on the support unit, and the support unit can adjust the angle change of the angle of attack of the large-sized aircraft. A hole is formed in the middle of the turntable base. The upper end of the motion unit passes through the hole and is fixedly connected to the support unit. The fixing unit is located below the turntable base and is fixedly connected to the lower plane of the turntable base. The motion unit is connected to the fixing unit and can move in the vertical direction, driving the large-sized aircraft to perform heaving motion along the direction perpendicular to the oncoming flow of the wind tunnel. This mechanism can increase the size of the low-speed dynamic derivative heaving oscillation test model to the order of 3-4 m, realizing a leapfrog improvement in the test Reynolds number simulation ability, and providing more real and stable data for the development process of large aircraft.

Description

Technical Field

[0001] The present invention belongs to the field of wind tunnel tests, and particularly relates to a simulation mechanism for heaving oscillation tests of large-scale models. Background Art

[0002] Dynamic derivatives are the derivatives of the aerodynamic coefficients of an aircraft with respect to the time change rate of the aircraft attitude parameters. They are essential original aerodynamic data for aircraft guidance systems, control systems, dynamic quality analysis, handling and stability system analysis, and control law design. At present, the main means to obtain dynamic derivatives include wind tunnel tests, numerical simulations, model flight or flight test parameter identification, etc. The numerical simulation method requires a long calculation time, is not suitable for obtaining a large amount of data, and the calculation methods and accuracy in the medium and large angle of attack ranges still need to be further studied. The model flight or flight test methods have deficiencies such as high costs, long implementation cycles, safety risks, poor repeatability, and low parameter identification accuracy. Moreover, model flight and flight tests cannot be safely carried out without dynamic derivatives. Therefore, they are not suitable as the main means for a model to obtain dynamic derivatives. Wind tunnel tests do not have the above problems and thus have become the most important means for obtaining aircraft dynamic stability data at home and abroad at present. Currently, the main wind tunnels for dynamic derivative tests in China are below the 4m level in size, and the model size is within the 2m level. When large aircraft are tested, the model scale ratio is relatively large, resulting in problems such as distortion of model detail simulation, insufficient Re number, and inaccurate simulation of the flow state, reducing the accuracy of the test data obtained and affecting the layout design and performance evaluation of large aircraft. Therefore, a simulation mechanism for heaving oscillation tests of large-scale aircraft is needed. Summary of the Invention

[0003] The purpose of the present invention is to provide a simulation mechanism for heaving oscillation tests of large-scale aircraft, which can carry out research on the influence of aerodynamic characteristics of dynamic derivative tests of large-scale aircraft in a wind tunnel, reduce flight test risks, shorten the new aircraft development cycle, and provide necessary technical guarantees for the safe flight of the aircraft.

[0004] The technical solution adopted by the present invention is: a simulation mechanism for heaving oscillation tests of large-scale aircraft, including a turntable base, a large-scale aircraft, a support unit, a motion unit, and a fixing unit. The large-scale aircraft is installed on the support unit, and the upper end of the support unit can adjust the angle change of the angle of attack of the large-scale aircraft. A hole is opened in the middle of the turntable base. The upper part of the fixing unit passes through the hole and protrudes from the turntable base, and the lower part of the fixing unit is located below the turntable base and is fixedly connected to the turntable base. The motion unit is located inside the fixing unit, connected to the fixing unit, and can move vertically. The upper end of the motion unit is fixedly connected to the lower end of the support unit, thereby driving the large-scale aircraft to perform heaving motion in a direction perpendicular to the wind tunnel oncoming flow direction.

[0005] Furthermore, the support unit includes a balance, a balance sleeve, a taper sleeve, a sleeve rotating shaft, a fork support, a two-way lock, an angle changer, a guide key, a locking pin and a support rod. The large-sized aircraft is fixedly connected to the balance. The balance and the balance sleeve are connected by a tapered surface fit, and the balance is locked by the taper sleeve. The balance sleeve is rotatably connected to both sides of the upper end of the fork support through the sleeve rotating shaft. The lower end of the fork support is sleeved on the upper end of the angle changer. The outer walls of the fork support and the angle changer are fixedly connected by the two-way lock. The angle changer is fixedly installed in the central hole at the upper end of the support rod through the locking pin. A guide key is installed between the fork support and the angle changer. Under the action of the guide key, the contact and separation from the balance sleeve are realized by rotating the two-way lock, thereby achieving the adjustment of the angle of attack of the large-sized aircraft.

[0006] Furthermore, the fixing unit includes a support base, two sets of optical bar mounting seats and two sets of optical bars. The upper part of the support base passes through the hole and protrudes from the turntable base. The lower part of the support base is detachably and fixedly connected to the lower plane of the turntable base. On the inner wall of the support base, two sets of optical bar mounting seats are symmetrically and fixedly connected on both sides centered on the axis of the moving unit. One set of optical bars is fixedly installed on each set of optical bar mounting seats. The part of the moving unit located inside the support base is slidably connected to the two sets of optical bars respectively.

[0007] Furthermore, the moving unit includes a support rod mounting seat, a moving box body, an oil cylinder moving seat, an oil cylinder, an oil cylinder fixing seat, an oil cylinder pin and four sets of chain-type V-shaped sliding mechanisms. The lower end of the support rod is connected to the support rod mounting seat by a flange. The support rod mounting seat is fixedly connected to the inside of the moving box body. The piston rod of the oil cylinder is connected to the oil cylinder moving seat through the oil cylinder pin. The oil cylinder moving seat is fixed at the middle position of the moving box body. The cylinder barrel of the oil cylinder is fixedly connected to the side wall of the support base through the oil cylinder fixing seat. On both sides of the axis of the moving box body, four sets of chain-type V-shaped sliding mechanisms are symmetrically and fixedly connected respectively. Each set of chain-type V-shaped sliding mechanisms is wrapped on the optical bar and is slidably connected to the optical bar.

[0008] Furthermore, the periphery and upper part of the upper part of the support base are detachably and fixedly connected with a front windshield, a middle windshield, a rear windshield and an upper windshield.

[0009] Furthermore, there are two sets of vertical guide frames on both sides of the support base. The upper end of each set of guide frames is fixedly connected to the lower plane of the turntable base. A vertical guide rod is fixedly connected between each set of guide frames. Both sides of the support base are slidably connected to the two sets of guide rods through guide seats respectively. After the test, the support base is separated from the turntable base and drops along the guide rod, quickly moving outside the wind tunnel to save the switching time of the wind tunnel equipment.

[0010] Advantages and beneficial effects of the present invention: This mechanism can carry out research on the influence of aerodynamic characteristics of dynamic derivatives of large-scale aircraft in a horizontal wind tunnel, measure its dynamic performance response parameters, and master its motion law. The size of the low-speed dynamic derivative heave oscillation test model can be increased to the order of 3-4m, achieving a leapfrog improvement in the test Reynolds number simulation ability, and providing more real and stable data for the development of large aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a three-dimensional structural schematic diagram of the present invention;

[0012] Figure 2 is a front view sectional view of the device of the present invention;

[0013] Figure 3 is a schematic diagram of the connection between the chain-type V-shaped sliding mechanism and the optical bar;

[0014] Figure 4 is a side view sectional view of the device of the present invention;

[0015] Figure 5 is a top view of the device of the present invention (excluding large-scale aircraft); DETAILED DESCRIPTION OF THE INVENTION

[0016] The present invention will be further described below with reference to the accompanying drawings of the specification:

[0017] Embodiment 1

[0018] As Figures 1-5 shown, a heave oscillation test simulation mechanism for a large-scale aircraft includes a turntable base, a large-scale aircraft, a support unit, a motion unit, and a fixing unit. It is characterized in that: the large-scale aircraft is installed on the support unit, and the upper end of the support unit can adjust the angle change of the angle of attack of the large-scale aircraft. A hole is opened in the middle of the turntable base, the upper part of the fixing unit passes through the hole and protrudes from the turntable base, the lower part of the fixing unit is located below the turntable base and is fixedly connected to the turntable base. The motion unit is located inside the fixing unit and is connected to the fixing unit and can move in the vertical direction. The upper end of the motion unit is fixedly connected to the lower end of the support unit, thereby driving the large-scale aircraft to perform heave motion perpendicular to the wind tunnel oncoming flow direction.

[0019] As Figure 2As shown in the figure, the support unit includes a balance 19, a balance sleeve 3, a taper sleeve 2, a sleeve rotating shaft 4, a fork bracket 20, a two-way lock 5, an angle changer 22, a guide key 21, a locking pin 23, and a support rod 6. The large-size aircraft 1 is fixedly connected to the balance 19. The balance 19 and the balance sleeve 3 are connected by a tapered surface fit, and the balance 19 is locked by the taper sleeve 2. The balance sleeve 3 is rotatably connected to both sides of the upper end of the fork bracket 20 through the sleeve rotating shaft 4. The lower end of the fork bracket 20 is sleeved on the upper end of the angle changer 22. The outer walls of the fork bracket 20 and the angle changer 22 are fixedly connected by the two-way lock 5. The angle changer 22 is fixed in the inner hole at the upper end of the support rod 6 through the locking pin 23. A guide key 21 is installed between the fork bracket 20 and the angle changer 22. Under the action of the guide key 21, the contact and separation with the balance sleeve 3 are realized by rotating the two-way lock 5, thereby achieving the adjustment of the angle of attack of the large-size aircraft 1.

[0020] As Figure 2 , 4 shown in the figure, the fixing unit includes a support base 18, two sets of optical bar mounting seats 17, and two sets of optical bars 15. The upper part of the support base 18 passes through the middle hole of the turntable base 27 and protrudes from the turntable base. The lower part of the support base 18 is detachably and fixedly connected to the lower plane of the turntable base 27. On the inner wall of the support base 18, two sets of optical bar mounting seats 17 are symmetrically and fixedly connected on both sides with the axis of the moving unit as the center. One set of optical bars 15 is fixedly installed on each set of optical bar mounting seats 17. The part of the moving unit located inside the support base 18 is slidably connected to the two sets of optical bars 15 respectively.

[0021] As Figures 2-5 shown in the figure, the moving unit includes a support rod mounting seat 24, a moving box body 26, an oil cylinder moving seat 29, an oil cylinder 31, an oil cylinder fixing seat 34, an oil cylinder pin 30, and four sets of chain-type V-shaped sliding mechanisms. The lower end of the support rod 6 is connected to the support rod mounting seat 24 by a flange. The support rod mounting seat 24 is fixedly connected to the inside of the moving box body 26. The piston rod of the oil cylinder 31 is connected to the oil cylinder moving seat 29 through the oil cylinder pin 30. The oil cylinder moving seat 29 is fixed at the middle position of the moving box body 26. The cylinder barrel of the oil cylinder 31 is fixedly connected to the side wall of the support base 18 through the oil cylinder fixing seat 34. On both sides of the axis of the moving box body 26, four sets of chain-type V-shaped sliding mechanisms are symmetrically and fixedly connected respectively. Each set of chain-type V-shaped sliding mechanisms is wrapped on the optical bar 16 and is slidably connected to the optical bar 16.

[0022] As Figures 2-3As shown, due to the large size and fast heaving speed of the test object, the mechanism will generate strong impact forces during the heaving simulation movement, and at the same time, it will generate large radial loads under the action of wind loads. Traditional standard components such as linear guides cannot meet the usage requirements, so a targeted design is carried out for this working condition. Multiple sets of sliding pair bodies 15 form a chain structure through connecting lugs 13 and pins 14. Two sets of chain structures are installed on the V-shaped sliding main body 10. Each set of V-shaped sliding main bodies 10 is fixed on the sliding body base 11. Each set of V-shaped sliding main bodies is wrapped around the optical rod 16 in a V shape and can achieve rapid alternating movement in the vertical direction under the push of the oil cylinder 31.

[0023] As Figures 1-2 shown in FIGS. 3 and 4, the upper part of the support seat 18 is located inside the wind tunnel. Its periphery and upper part include a front wind shield 7, a middle wind shield 8, a rear wind shield 9 and an upper wind shield 25, which are fixed by screw connections to form a closed frame. A hole is opened in the middle of the upper wind shield 25 for the support rod 6 to pass through.

[0024] As Figures 1-2 shown in FIGS. 3 and 4, there are two sets of vertical guide frames 32 on both sides of the support seat 18. The upper end of each set of guide frames 32 is fixedly connected to the lower plane of the turntable base 27. A vertical guide rod 28 is fixedly connected between each set of guide frames 32. The two sides of the support seat 18 are respectively slidably connected to the two sets of guide rods 28 through guide seats. After the test is completed, the support seat 18 is separated from the turntable base 27 and falls along the guide rod 28, moving the whole mechanism of the present invention vertically to the lower part of the lower turntable 27, that is, outside the wind tunnel flow field, and is fixed at the bottom by a locking nut 33 to prevent it from moving up and down.

Claims

1. A simulation mechanism for heaving oscillation test of a large-sized aircraft, comprising a turntable base, a large-sized aircraft, a support unit, a motion unit and a fixing unit, characterized in that: The large-sized aircraft is mounted on a support unit. The upper end of the support unit can adjust the angle of attack of the large-sized aircraft. A hole is formed in the middle of the turntable base. The upper part of the fixing unit passes through the hole and protrudes from the turntable base. The lower part of the fixing unit is located below the turntable base and is fixedly connected to the turntable base. The moving unit is located inside the fixing unit, connected to the fixing unit, and can move in the vertical direction. The upper end of the moving unit is fixedly connected to the lower end of the support unit, thereby driving the large-sized aircraft to perform heaving motion perpendicular to the oncoming flow direction of the wind tunnel. The support unit includes a balance, a balance sleeve, a taper sleeve, a sleeve rotating shaft, a fork, a two-way locking device, an angle changer, a guide key, a locking pin, and a support rod. The large-sized aircraft is fixedly connected to the balance. The balance and the balance sleeve are connected by a tapered surface fit, and the balance is locked by the taper sleeve. The balance sleeve is rotatably connected to both sides of the upper end of the fork through the sleeve rotating shaft. The lower end of the fork is sleeved on the upper end of the angle changer. The outer walls of the fork and the angle changer are fixedly connected by the two-way locking device. The angle changer is fixedly installed in the central hole at the upper end of the support rod through the locking pin. A guide key is installed between the fork and the angle changer. Under the action of the guide key, the two-way locking device is rotated to achieve contact with and separation from the balance sleeve, thereby adjusting the angle of attack of the large-sized aircraft. The fixing unit includes a support base, two groups of optical bar mounting seats, and two groups of optical bars. The upper part of the support base passes through the hole and protrudes from the turntable base. The lower part of the support base is detachably and fixedly connected to the lower plane of the turntable base. Two groups of optical bar mounting seats are symmetrically and fixedly connected to both sides of the inner wall of the support base with the axis of the moving unit as the center. Each group of optical bar mounting seats is fixedly installed with a group of optical bars. The moving unit is located inside the support base and is respectively slidably connected to the two groups of optical bars. The moving unit includes a support rod mounting seat, a moving box body, an oil cylinder moving seat, an oil cylinder, an oil cylinder fixing seat, an oil cylinder pin, and four groups of chain-type V-shaped sliding mechanisms. The lower end of the support rod is connected to the support rod mounting seat by a flange. The support rod mounting seat is fixedly connected to the inside of the moving box body. The piston rod of the oil cylinder is connected to the oil cylinder moving seat through the oil cylinder pin. The oil cylinder moving seat is fixed at the middle position of the moving box body. The cylinder barrel of the oil cylinder is fixedly connected to the side wall of the support base through the oil cylinder fixing seat. Four groups of chain-type V-shaped sliding mechanisms are symmetrically and fixedly connected to both sides of the axis of the moving box body. Each group of chain-type V-shaped sliding mechanisms is wrapped around the optical bar and is slidably connected to the optical bar.

2. The large-size aircraft heave oscillation test simulation mechanism according to claim 1, wherein: The periphery and upper part of the upper part of the support base are detachably and fixedly connected with a front windshield, a middle windshield, a rear windshield, and an upper windshield.

3. The large-size aircraft heave oscillation test simulation mechanism according to claim 2, wherein: There are two groups of vertical guide frames on both sides of the support base. The upper end of each group of guide frames is fixedly connected to the lower plane of the turntable base. A vertical guide rod is fixedly connected between each group of guide frames. The two sides of the support base are respectively slidably connected to the two groups of guide rods through guide seats. After the test, the support base is separated from the turntable base and falls along the guide rod and moves outside the wind tunnel.

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