A system and method for simulating a high-speed drop test of an aircraft fuel tank

Abstract

The application discloses a kind of simulation aircraft fuel tank high-speed drop test system and test method, it is related to the technical field of fuel tank drop test, system includes: fuel tank, unmanned aerial vehicle, hover control subsystem, throw control subsystem, drop support subsystem, data measurement subsystem;Fuel tank is hung on unmanned aerial vehicle;Hover control subsystem controls the flight height of unmanned aerial vehicle;Throw control subsystem controls the fuel tank on unmanned aerial vehicle to be thrown;The drop support subsystem includes drop plate, for catching the fuel tank being thrown;The data measurement subsystem is used to collect the image data and temperature field data when the fuel tank being thrown drops in drop plate.The application can simulate the fuel tank drop impact process of fuel tank, for studying the influence of fuel tank drop attitude, drop speed, collision angle drop face stiffness on fuel throwing distribution characteristics.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil tank drop test, in particular to a system and method for simulating high-speed drop test of an aircraft oil tank. BACKGROUND

[0002] With the wide application of civil helicopters in sightseeing, forest fire fighting and public security law enforcement, engineers pay more and more attention to the safety performance design of civil helicopters. Accident investigation shows that the fire or explosion of the oil tank caused by the drop of the civil helicopter is the main cause of personnel casualties. Therefore, by studying the fuel leakage and distribution and the combustion and explosion mechanism of the civil helicopter oil tank during the drop, targeted oil tank explosion suppression measures can be taken to suppress the fire and explosion caused by the high-speed drop of the oil tank and reduce the personnel casualties in the drop accident of the civil helicopter, which is of great significance to improve the safety performance design of the civil helicopter. Therefore, it is necessary to carry out high-speed drop test of the civil helicopter oil tank.

[0003] The mechanism of the fire and explosion of the civil helicopter oil tank is closely related to the fuel distribution characteristics, and the influence of the drop attitude, drop speed, impact angle and drop surface stiffness of the oil tank on the fuel distribution characteristics will help reveal the mechanism of the fire and explosion caused by the high-speed drop of the oil tank of the civil helicopter. Therefore, it is of great scientific significance to analyze the influence of the above factors on the fuel distribution characteristics during the high-speed drop of the oil tank of the civil helicopter by experimental research, which helps to strengthen the intrinsic safety design of the oil tank of the civil helicopter from the perspective of high-speed drop explosion suppression.

[0004] At present, although the drop of the oil tank of the civil helicopter has been studied, the research mainly focuses on the numerical simulation of the oil tank of the civil helicopter. There is a lack of research on the high-speed drop test of the oil tank of the civil helicopter and the fuel distribution characteristics based on the drop test of the oil tank. Therefore, the main technical problems faced by the research on the fire and explosion of the oil tank of the civil helicopter include the following two points: 1. Lack of test system and test method for simulating the high-speed drop of the oil tank of the helicopter; 2. Lack of research on the influence of the drop attitude, drop speed, impact angle and drop surface stiffness of the oil tank on the fuel distribution characteristics. SUMMARY

[0005] In order to overcome the defects in the prior art, the present application provides a system for simulating high-speed drop test of an aircraft oil tank, which can simulate the oil tank drop impact process and is used for studying the influence of the drop attitude, drop speed, impact angle and drop surface stiffness of the oil tank on the fuel distribution characteristics.

[0006] To achieve the above purpose, the present application adopts the following technical scheme, comprising:

[0007] A kind of simulation aircraft fuel tank high-speed drop test system, comprising: fuel tank, unmanned aerial vehicle, hover control subsystem, throw control subsystem, drop support subsystem, data measurement subsystem;

[0008] The fuel tank is hung on unmanned aerial vehicle;The hover control subsystem is used to control the flight height of unmanned aerial vehicle;The throw control subsystem is used to control the fuel tank on unmanned aerial vehicle is thrown;The drop support subsystem includes drop plate, for catching the fuel tank being thrown;The data measurement subsystem is used to collect the image data and temperature field data of the fuel tank being thrown when falling on drop plate.

[0009] Preferably, the drop support subsystem includes: support frame, first base, second base, third base, rear support rod and drop plate;

[0010] Support frame is beam steel frame with longitudinal and transverse beams staggered, and the support frame is used to fix and support the drop plate, and the drop plate is used to bear the impact force of the fuel tank falling;

[0011] The bottom ends of the two longitudinal beams on the left and right sides of the support frame are respectively connected with the first base and the second base;

[0012] The support frame is provided with a movable support, one end of the rear support rod is connected with the movable support on the support frame, and the other end of the rear support rod is connected with the third base;

[0013] The first base, the second base and the third base are fixed on the horizontal ground, and the third base is fixed behind the first base and the second base, and the drop plate has a certain inclination angle relative to the horizontal ground.

[0014] Preferably, the rear support rod is assembled by a steel pipe, a flange type hydraulic cylinder and a piston rod;The flange type hydraulic cylinder is connected with a hydraulic control box through a hydraulic oil pipe, and the piston rod in the flange type hydraulic cylinder is controlled to extend or shorten in its stroke range through the hydraulic control box, so as to control the rear support rod to extend or shorten along the rod axis direction;The rear support rod extends or shortens along the rod axis direction to drive the movable support on the support frame to rotate, so as to adjust the inclination angle of the drop plate.

[0015] Preferably, the data measurement subsystem includes: dynamic inclination sensor, angle display, first camera, second camera, infrared thermal imager and computer;

[0016] The dynamic inclination sensor is installed on the bottom surface of the drop plate, and is used to measure the inclination angle of the drop plate relative to the horizontal ground;

[0017] The first camera is located in the front direction of the drop plate, and is used to record the complete process of the fuel tank falling to the drop plate from the front direction of the drop plate, i.e. to collect front image data;

[0018] The second camera is installed in the side direction of the falling plate, and is used for recording the complete process of the oil tank falling to the falling plate from the side direction of the falling plate, i.e. collecting side image data;

[0019] The infrared thermal imager is installed in the front direction of the falling plate, and is used for collecting temperature field data when the oil tank collides with the falling plate;

[0020] The first camera, the second camera and the infrared thermal imager are connected with the computer through anti-noise signal lines, and the collected data are uploaded to the computer, and the image data and the temperature field data of the fuel throwing distribution are processed and analyzed based on the computer.

[0021] Preferably, different falling surface rigidities are realized by paving different materials on the surface of the falling plate.

[0022] Preferably, the throwing control subsystem comprises a fixed plate, a signal adapter, two slide rails, four throwing devices, a first hanging rope, a second hanging rope, a third hanging rope and a fourth hanging rope.

[0023] The fixed plate is installed at the bottom of the body of the unmanned aerial vehicle, and is used for fixing the signal adapter; the signal adapter is fixed on the bottom plate of the fixed plate; the two slide rails are fixed on the two sides of the bottom plate of the signal adapter; and each slide rail is connected with two end portions of the throwing device, i.e. four throwing devices.

[0024] The signal adapter is connected with the throwing device through a signal line, and the pushing rod is arranged in the throwing device; the signal adapter is used for receiving and processing operation instructions sent by the remote controller, and sending the operation instructions to the throwing device through the signal line, so as to control the pushing rod in the throwing device to move forward and backward;

[0025] The first hanging rope, the second hanging rope, the third hanging rope and the fourth hanging rope are sequentially hung on the pushing rod in the four throwing devices; the first hanging rope, the second hanging rope, the third hanging rope and the fourth hanging rope are connected with four top corners of the top plate of the oil tank respectively; when the pushing rod moves backward, the hanging ropes are separated from the pushing rod, and the throwing of the oil tank is realized;

[0026] The length of the four hanging ropes is adjusted, so as to control the included angle between the suspended oil tank and the horizontal ground.

[0027] Preferably, the hovering control subsystem comprises a body camera arranged on the unmanned aerial vehicle, a laser emitter and a position finder.

[0028] The body camera is used for acquiring a flight field of view; the laser emitter is used for measuring the height of the unmanned aerial vehicle from the ground; the position finder is used for measuring the height of the oil tank from the ground; and the flight of the unmanned aerial vehicle is controlled through the remote controller.

[0029] The application further provides a test method of the simulation aircraft oil tank high-speed falling test system, and the test method comprises the following steps:

[0030] S1, calculating the flight height h of the unmanned aerial vehicle according to the required falling speed v of the test d , the flight height h of the unmanned aerial vehicle d , that is, the height from the ground;

[0031] S2, calculating the inclination angle θ of the falling plate according to the required tank attitude angle α and tank collision angle β of the test;

[0032] S3, selecting the surface layer of the corresponding material according to the required falling surface rigidity of the test, and paving the surface layer on the surface of the falling plate;

[0033] S4, fixing the falling plate on the horizontal ground, and the inclination angle of the falling plate relative to the horizontal ground is θ;

[0034] S5, according to the tank attitude angle α, the tank is hung on the unmanned aerial vehicle, and the included angle between the hung tank and the horizontal ground is α;

[0035] S6, the hovering control subsystem controls the unmanned aerial vehicle to fly to the height h d from the ground and hover;

[0036] S7, the throwing control subsystem throws the tank hung on the unmanned aerial vehicle;

[0037] S8, the data measurement subsystem collects image data and temperature field data of the tank when the tank falls on the falling plate.

[0038] Preferably, in step S1, the flight height h d of the unmanned aerial vehicle is calculated in the following manner:

[0039]

[0040] Wherein, v d is the falling speed of the tank required by the test, and the unit is m / s; g is the acceleration of gravity, and g is 9.81 m / s 2 .

[0041] Preferably, in step S2, the inclination angle θ of the falling plate is calculated in the following manner:

[0042] θ = α + β

[0043] Wherein, α is the tank attitude angle required by the test, that is, the included angle between the tank and the horizontal ground, and the unit is °; β is the tank collision angle required by the test, that is, the included angle between the tank and the falling plate when the tank falls on the falling plate, and the unit is °.

[0044] The advantages of the present application are:

[0045] (1) The test system of the present application can simulate the oil tank falling impact process of the oil tank, study the influence of the oil tank falling posture, falling speed, collision angle and falling surface stiffness on the fuel throwing distribution characteristics, and can be used for studying the fuel throwing distribution characteristics in the oil tank falling impact process of the civil helicopter, solving the problem of lacking fuel tank high-speed crash test system in the prior art.

[0046] (2) The hovering control subsystem, the throwing control subsystem and the falling support subsystem of the present application can simulate the falling speed, the falling posture, the collision angle and the falling surface stiffness, can study the influence of different factors on the fuel throwing distribution characteristics, and has important engineering significance for studying the coupling relationship between the oil tank fire explosion mechanism and the fuel throwing distribution of the civil helicopter.

[0047] (3) The falling support subsystem of the present application can safely and reasonably carry out fuel tank falling impact tests of different collision angles and different falling surface stiffnesses, not only can enrich the working condition design of the falling test, but also is beneficial to analyzing the influence mechanism of different collision angles and different falling surface stiffnesses on the damage form of the oil tank from a large number of test results, and then guiding the intrinsic safety design of the oil tank of the civil helicopter. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 It is a structural schematic diagram of the oil tank high-speed falling test system for simulating the civil helicopter.

[0049] Figure 2 It is a structural schematic diagram of the oil tank high-speed falling test system for simulating the civil helicopter.

[0050] Figure 3 It is a partial enlarged view of the hovering control subsystem.

[0051] Figure 4 It is a partial enlarged view of the throwing device.

[0052] Figure 5 It is a three-dimensional structural schematic diagram of the throwing control subsystem.

[0053] Figure 6 It is a partial enlarged view of the support frame.

[0054] Figure 7 It is a partial enlarged view of the support frame. Figure 6

[0055] Figure 8 It is a B-B sectional view in the Figure 6

[0056] Figure 9 It is a front view structural schematic diagram of the base.

[0057] Figure 10 It is a side view structural schematic diagram of the base. ​​

[0058] Figure 11 is a schematic view of a top structure of the base.

[0059] Figure 12 is a partial enlarged view of the thick shaft.

[0060] Figure 13 is a partial enlarged view of the rear support rod.

[0061] Figure 14 is a C-C section view in Figure 13 .

[0062] Figure 15 is a partial enlarged view of the falling plate.

[0063] Figure 16 is a schematic view of a section structure of the falling plate and the surface layer.

[0064] Figure 17 is a principle diagram for calculating the inclination angle of the falling plate.

[0065] The meanings of the reference signs in the drawings are as follows:

[0066] 1 - oil tank, 2 - unmanned aerial vehicle, 3 - remote controller, 4 - fuselage camera, 5 - laser emitter, 6 - positioner, 7 - fixed plate, 8 - signal adapter, 9 - slide rail, 10 - throwing device, 11 - first hanging rope, 12 - second hanging rope, 13 - third hanging rope, 14 - fourth hanging rope, 15 - support frame, 16 - first base, 17 - second base, 18 - third base, 19 - thick shaft with hexagonal nut, 20 - rear support rod, 21 - falling plate, 22 - secondary beam, 23 - main beam, 24 - side longitudinal beam, 25 - dynamic inclination sensor, 26 - angle display, 27 - first camera, 28 - second camera, 29 - infrared thermal imager, 30 - computer, 31 - anti-noise signal line, 32 - first lifting ring, 33 - second lifting ring, 34 - third lifting ring, 35 - fourth lifting ring, 36 - movable support, 37 - flange type hydraulic cylinder, 38 - piston rod, 39 - hydraulic oil pipe, 40 - hydraulic control box, 41 - push rod of the throwing device, 42 - square steel pipe, 43 - surface layer. DETAILED DESCRIPTION

[0067] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0068] Embodiment 1

[0069] The present application is described in detail by the following examples. Figures 1-16As shown in the figure, a high-speed falling test system for simulating aircraft fuel tank is provided, which comprises a fuel tank 1, a UAV 2, a remote controller 3, a hovering control subsystem, a throwing control subsystem, a falling support subsystem, and a data measurement subsystem.

[0070] The fuel tank 1 is suspended on the UAV 2; the hovering control subsystem is used to control the flight height of the UAV 2; the throwing control subsystem is used to control the throwing of the fuel tank 1 on the UAV 2; the falling support subsystem is used to catch the thrown fuel tank 1; and the data measurement subsystem is used to collect image data and temperature field data of the falling fuel tank 1 when it falls on the falling plate 21. The remote controller 3 is used to remotely control the UAV 2 to complete the hoisting and transportation of the fuel tank 1 and the hovering throwing.

[0071] By Figure 2 As shown in the figure, the fuel tank 1 is a civilian fuel tank 1 with a top plate welded with lifting rings, and aviation fuel is contained in the fuel tank 1. The fuel tank 1 of a civilian helicopter can be obtained by disassembling the fuel venting system of the helicopter, and four lifting rings, including a first lifting ring 32, a second lifting ring 33, a third lifting ring 34, and a fourth lifting ring 35, are welded at four top corners of the top plate of the fuel tank 1 for suspending a hanging rope.

[0072] The UAV 2 is a commercially available industrial UAV, and the hoisting and transportation of the fuel tank 1 and the hovering throwing can be realized by modifying the fuselage structure of the UAV 2.

[0073] By Figure 3 , 5 As shown in the figure, the hovering control subsystem comprises a fuselage camera 4, a laser emitter 5, and a positioner 6 arranged on the UAV 2. The fuselage camera 4 provides a flight field of view for the UAV 2 to complete hoisting and transportation and hovering throwing; the main screen of the remote controller 3 can display the recording picture of the fuselage camera 4 in real time; the laser emitter 5 can accurately and in real time measure the height of the UAV 2 from the ground; and the positioner 6 can in real time measure the height of the fuel tank 1 from the ground. The fuselage camera 4 is a conventional commercially available camera.

[0074] By Figure 5As shown, the throwing control subsystem includes a fixed plate 7, a signal adapter seat 8, a slide rail 9, a throwing device 10, a first hanging rope 11, a second hanging rope 12, a third hanging rope 13, and a fourth hanging rope 14. The fixed plate 7 is installed at the bottom of the fuselage of the unmanned aerial vehicle 2 and is used to fix the signal adapter seat 8; the signal adapter seat 8 is fixed on the bottom plate of the fixed plate 7; two slide rails 9 are fixed on the two sides of the bottom plate of the signal adapter seat 8 through bolt connection; the two ends of each slide rail 9 are connected with the throwing device 10 through M12 bolt connection, that is, there are four throwing devices in total; the signal adapter seat 8 and the throwing device 10 are connected through signal lines, and the signal lines are distributed along the slide rails 9; the pushing rod 41 is arranged in the throwing device 10; the signal adapter seat 8 receives and processes the operation instructions sent by the remote controller 3, and sends the operation instructions to the throwing device 10 through the signal lines to control the pushing rod 41 in the throwing device 10 to move forward and backward, so as to control the throwing device 10 to complete the release action of the fuel tank 1, that is, the throwing action;

[0075] As shown in Figure 4 , the pushing rods 41 of the four throwing devices 10 are sequentially hung with the first hanging rope 11, the second hanging rope 12, the third hanging rope 13, and the fourth hanging rope 14, and the four hanging ropes are connected with the four top corners of the top plate of the fuel tank 1; when the pushing rod 41 is operated to move backward through the remote controller 3, the four hanging ropes will be separated from the pushing rods 41 of the throwing devices 10, and the release action of the fuel tank 1 is completed. The hanging rope is made of a plurality of steel wire ropes and is provided with hooks at both ends.

[0076] As shown in Figure 1 , the falling support subsystem includes a support frame 15, a first base 16, a second base 17, a third base 18, a thick shaft 19 with a hexagonal nut, a rear support rod 20, and a falling plate 21. As shown in Figure 6 , 7 , and 8, the support frame 15 is a beam type steel frame with longitudinal beams as secondary beams 22 and horizontal beams as main beams 23, and the longitudinal beams and the horizontal beams are arranged alternately; the cross-sectional width of the longitudinal beam, that is, the secondary beam 22, is 50 mm, and the cross-sectional height is 100 mm; the cross-sectional width of the horizontal beam, that is, the main beam 23, is 70 mm, and the cross-sectional height is 200 mm; the long side dimension of the support frame 15 is 3.60 m, and the short side dimension is 2.10 m; the support frame 15 is used to fix and support the falling plate 21; the falling plate 21 is a structural member for bearing the impact force of the high-speed falling of the fuel tank 1, and the size (long side dimension and short side dimension) of the falling plate 21 is the same as that of the support frame 15; as shown in Figure 15 , the falling plate 21 is a large steel plate composed of six small rectangular steel plates, and the long side dimension of each small steel plate is 1.80 m and the short side dimension is 0.70 m; the falling plate 21 is fixed with the support frame 15 through M20 bolts; as shown in Figure 1 , 9As shown in Figure 10, the first base 16 and the second base 17 are located at the beam ends of the two side longitudinal beams 24 of the support frame 15. The side longitudinal beams 24 are connected to the first base 16 and the second base 17 by a thick shaft 19 containing a hexagonal nut. Figure 12 As shown, the thick shaft 19, containing a hexagonal nut, is a cylindrical connector with a smooth surface in the middle but threaded surfaces at the ends. The cross-sectional diameter of the thick shaft 19 is 10 cm. The rear support rod 20 is an important structural component supporting the drop plate 21 and the support frame 15. One end of the rear support rod 20 is connected to the support frame 15 via the thick shaft 19. Figure 8 As shown, a movable support 36 adapted to the thick shaft 19 is welded onto the support frame 15; the other end of the rear support rod 20 is connected to the third base 18 via the thick shaft 19; by Figure 11 As shown, the first base 16, the second base 17, and the third base 18 are fixed to the horizontal ground by M20 anchor bolts, wherein the third base 18 is fixed 5m behind the first base 16 and the second base 17.

[0077] Depend on Figure 1 As shown, the data measurement subsystem includes a dynamic tilt sensor 25, an angle display 26, a first camera 27, a second camera 28, an infrared thermal imager 29, a computer 30, and a noise-resistant signal line 31. A dynamic tilt sensor 25 is installed on the bottom surface of the drop plate 21 to measure the tilt angle of the drop plate 21 relative to the horizontal ground. Angle display 26 is connected to the dynamic tilt sensor 25 via a noise-resistant signal line 31, allowing the angle display 26 to observe the tilt angle of the drop plate 21 in real time. A first camera 27 is installed 20m away from the front of the drop plate 21, and a second camera 28 is installed 20m away from the side of the drop plate 21. The first camera 27 and the second camera 28 respectively capture the complete process of fuel spillage distribution when the fuel tank 1 falls at high speed onto the drop plate 21 from different angles. An infrared thermal imager 29 is installed 15m away from the front of the drop plate 21 to measure the temperature field change during the fuel spillage process. The first camera 27, the second camera 28, and the infrared thermal imager 29 are connected to a computer 30 via a noise-resistant signal line 31, and the computer 30 processes and analyzes the image data and temperature field data of the fuel spillage distribution.

[0078] Depend on Figure 13 , 14As shown, the rear support rod 20 is an adjustable combination structure of the falling plate 21, which is assembled by a square steel tube 42, a flange hydraulic cylinder 37 and a piston rod 38. The cross-sectional dimension of the square steel tube 42 is 10 cm x 10 cm, the rated pressure of the flange hydraulic cylinder 37 is 20 MPa, the inner diameter of the cylinder is 73 mm, the rod diameter of the piston rod is 35 mm, the piston stroke is 50 mm-6000 mm, the flange hydraulic cylinder 37 is connected to a hydraulic control box 40 through a hydraulic oil pipe 39, and the operation of the hydraulic control box 40 can control the piston rod 38 in the flange hydraulic cylinder 37 to extend or shorten in the stroke range, so that the rear support rod 20 extends or shortens along the rod axis direction, and the linear motion of the rear support rod 20 along the rod axis direction drives the movable support 36 to rotate, and the inclination angle of the falling plate 21 changes accordingly.

[0079] As shown in the figure, Figure 16 As shown, the surface of the rectangular small steel plate constituting the falling plate 21 can be paved with a surface layer 43 of different materials, the surface layer 43 has the same planar geometric dimension as the rectangular small steel plate, the surface layer 43 and the rectangular small steel plate have bolt holes at the same position in the plane, and M20 bolts can be used to fix the rectangular small steel plate and the surface layer 43 on the support frame 15. According to the required falling surface stiffness of the test, the material of the surface layer 43 can be selected from rock, asphalt, soil and concrete. In this embodiment, semi-rigid collision between the oil tank and the falling plate is required, so the material of the surface layer 43 is asphalt, and the asphalt surface layer with serious damage can be replaced by disassembling the bolts according to the damage of the falling surface in the test.

[0080] In this embodiment, the materials of the fixed plate 7, the signal adapter 8, the slide rail 9 and the throwing device 10 are all carbon fiber reinforced epoxy resin composites, which have the characteristics of high strength and high modulus. The slide rail 9 has upper and lower sliding grooves. The upper sliding groove is used to adjust the position of the signal adapter 8 to improve the overall stability and anti-overturning of the fuselage, and the lower sliding groove is used to adjust the position of the throwing device 10. Meanwhile, the other steel structural parts are made of Q345.

[0081] Embodiment 2

[0082] A method for simulating high-speed falling test of an aircraft fuel tank, comprising the following steps:

[0083] S21, according to the falling speed v d = 36 m / s of the oil tank 1, calculating the flight height h d = 66 m of the unmanned aerial vehicle 2.

[0084] In step S21, according to the falling speed v d = 36 m / s of the oil tank 1, calculating the flight height h d , i.e. the height from the ground, which is specifically as follows:

[0085]

[0086] wherein g is the gravity acceleration, g=9.81m / s 2 , v d is the design value of the falling speed of the oil tank.

[0087] S22, the inclination angle θ of the falling plate 21 is calculated according to the oil tank attitude angle α=15 ° and the oil tank collision angle β=45 ° . °

[0088] In step S22, the mathematical principle for calculating the inclination angle θ of the falling plate 21 can refer to Figure 17 , and the calculation is as follows:

[0089] θ=α+β=15 ° +45 ° =60 °

[0090] wherein α is the oil tank attitude angle, unit: °; β is the oil tank collision angle, which is the included angle between the oil tank and the falling plate when the collision occurs, unit: °.

[0091] S23, according to the falling surface stiffness required by the test, the surface layer 43 is paved on the small steel plates, and the M20 bolts are used to fix the six small steel plates and the surface layer on the support frame 15 in turn.

[0092] S24, the support frame 15 is hoisted by mechanical equipment, the support frame 15 is fixed on the first base 16 and the second base 17 by the thick shaft 19, at the same time, the rear support rod 20 is hoisted by mechanical equipment, and the two ends of the rear support rod 20 are fixed on the third base 18 and the movable support 36 of the support frame 15 by the thick shaft 19; the dynamic inclination angle sensor 25 installed on the support frame 15 is connected to the angle display 26, the flange type hydraulic oil cylinder 37 is connected to the hydraulic control box 40 by the hydraulic oil pipe 39, and the hydraulic control box 40 is operated to make the falling plate 21 rotate, when the reading on the angle display 26 is angle θ=60 ° , the operation of the hydraulic control box 40 is stopped.

[0093] S25, the slide rail 9 and the throwing device 10 are fixed below the signal adapter seat 8 by M12 bolts, the first hanging rope 11, the second hanging rope 12, the third hanging rope 13 and the fourth hanging rope 14 with corresponding lengths are selected according to the oil tank attitude angle α=15 ° , and the four hanging ropes are used to hang the oil tank 1 filled with aviation fuel on the throwing device 10.

[0094] ​S26, turn on the onboard camera 4, laser emitter 5, and positioning device 6, and wirelessly connect the remote controller 3 to the drone 2. Use the remote controller 3 to control the drone 2 to fly to a distance and altitude h. d =66m and hovered.

[0095] S27, the remote controller 3 issues a throwing command, and the throwing control subsystem throws the fuel tank 1 suspended on the drone 2.

[0096] S28, the first camera 27, the second camera 28 and the infrared thermal imager 29 are connected to the computer 30 in sequence using the noise-resistant signal line 31. The computer 30 synchronously triggers the cameras and the infrared thermal imager 29 to record the test data in real time. The test personnel issue the throwing command to complete a high-speed drop test of the fuel tank, save the test data and prepare for the next test.

[0097] In step S25, based on the attitude angle α = 15° of fuel tank 1... ° Select the appropriate length of hanging rope, specifically including the following steps:

[0098] S2501, Determine the angle α between the bottom surface of fuel tank 1 and the horizontal plane according to the falling posture: α = 15° ° That is, attitude angle α = 15 ° ;

[0099] S2502, according to the mailbox attitude angle α = 15 ° Place fuel tank 1 on a horizontal surface, place drone 2 on a platform that is vertically higher than fuel tank 1, and connect four fuel tank rings and four throwing devices in sequence using four sufficiently long steel wire ropes of the same material as the first hanging rope 11.

[0100] S2503, the length of the four steel wire ropes when they are taut under the gravity of the oil tank 1 is the length that satisfies the attitude angle α of the oil tank 1 = 15°. ° Record the length of the hanging rope, then record the length of the four steel wire ropes in sequence, and then disassemble the four steel wire ropes.

[0101] S2504. Select the first hanging rope 11, the second hanging rope 12, the third hanging rope 13 and the fourth hanging rope 14 of the corresponding lengths according to the recorded lengths, and install the first hanging rope 11, the second hanging rope 12, the third hanging rope 13 and the fourth hanging rope 14 on the corresponding positions of the fuel tank lifting ring and the throwing device in sequence to complete the positioning of the fuel tank's falling posture.

[0102] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for simulating high-speed drop test of an aircraft fuel tank, characterized in that, the test system comprises a fuel tank (1), a UAV (2), a hovering control subsystem, a drop control subsystem, a drop support subsystem, and a data measurement subsystem; the fuel tank (1) is suspended on the UAV (2); the hovering control subsystem is used to control the flight height of the UAV (2); the drop control subsystem is used to control the fuel tank (1) suspended on the UAV (2) to be dropped; the drop support subsystem comprises a drop plate (21) for catching the dropped fuel tank (1); the data measurement subsystem is used to collect image data and temperature field data of the dropped fuel tank (1) when falling on the drop plate (21); the test method comprises the following steps: S1, falling speed according to the test requirements calculating the flight height of the drone (2) ; S2, the oil tank attitude angle according to the test requirement and the oil tank collision angle , calculate the inclination angle of the falling plate (21) ; S3, according to the required drop surface stiffness, a surface layer (43) of corresponding material is selected and laid on the surface of the drop plate (21); S4, fixing the falling plate (21) on the horizontal ground, and the inclination angle of the falling plate (21) relative to the horizontal ground is ; S5, according to the oil tank attitude angle , the oil tank (1) is suspended on the unmanned aerial vehicle (2), the angle between the suspended oil tank (1) and the horizontal ground is ; S6, the hovering control subsystem controls the UAV (2) to fly to a flight height of and hover; S7, the drop control subsystem drops the fuel tank (1) suspended on the UAV (2); S8, the data measurement subsystem collects image data and temperature field data of the dropped fuel tank (1) when falling on the drop plate (21); In step S2, the inclination angle of the falling plate (21) is calculated as follows: wherein, is the required tank attitude angle of the test, i.e. the angle between the tank (1) and the horizontal ground, in °; is the required tank impact angle of the test, i.e. the angle between the tank (1) and the drop plate (21) when the tank (1) falls on the drop plate (21), in °.

2. A method of simulating a high speed impact test of an aircraft fuel tank as defined in claim 1, wherein the drop support subsystem comprises a support frame (15), a first base (16), a second base (17), a third base (18), a rear support rod (20), and a drop plate (21); the support frame (15) is a beam type steel frame with longitudinal and transverse beams arranged alternately, which is used to fix and support the drop plate (21), and the drop plate (21) is used to bear the impact force of the fuel tank (1) when falling; the bottom ends of the two longitudinal beams (24) on the left and right sides of the support frame (15) are connected with the first base (16) and the second base (17), respectively; the support frame (15) is provided with a movable support (36), one end of the rear support rod (20) is connected with the movable support (36) on the support frame (15), and the other end of the rear support rod (20) is connected with the third base (18); the first base (16), the second base (17), and the third base (18) are fixed on the horizontal ground, and the third base (18) is fixed behind the first base (16) and the second base (17), and the drop plate (21) has an inclination angle relative to the horizontal ground.

3. A method of simulating a high speed impact test of an aircraft fuel tank as defined in claim 2, wherein the rear support rod (20) is assembled by a steel pipe (42), a flange type hydraulic cylinder (37), and a piston rod (38); the flange type hydraulic cylinder (37) is connected with a hydraulic control box (40) through a hydraulic oil pipe (39), the piston rod (38) in the flange type hydraulic cylinder (37) is controlled to extend or shorten within its stroke range through the hydraulic control box (40), and then the rear support rod (20) is controlled to extend or shorten along the rod axis direction; the extension or shortening of the rear support rod (20) along the rod axis direction drives the movable support (36) on the support frame (15) to rotate, so as to adjust the inclination angle of the drop plate (21).

4. The method of claim 2, wherein, the data measurement subsystem comprises a dynamic inclination sensor (25), an angle display (26), a first camera (27), a second camera (28), an infrared thermal imager (29), and a computer (30). A dynamic tilt sensor (25) is installed on the bottom surface of the falling plate (21) to measure the tilt angle of the falling plate (21) relative to the horizontal ground; A first camera (27) is located in the front direction of the falling plate (21) to record the entire process of the oil tank (1) falling onto the falling plate (21) from the front direction of the falling plate (21), that is, to collect front image data; A second camera (28) is installed in the side direction of the falling plate (21) to record the entire process of the oil tank (1) falling onto the falling plate (21) from the side direction of the falling plate (21), that is, to collect side image data; An infrared thermal imager (29) is installed in the front direction of the falling plate (21) to collect temperature field data when the oil tank (1) collides with the falling plate (21); The first camera (27), the second camera (28), and the infrared thermal imager (29) are respectively connected to the computer (30) through anti-noise signal lines (31), and the collected data is uploaded to the computer (30), and the image data and temperature field data of the fuel scattering distribution are processed and analyzed based on the computer (30).

5. A method of simulating a high speed impact test of an aircraft fuel tank as defined in claim 2, wherein, Different falling surface stiffnesses are achieved by paving different materials on the surface of the falling plate (21).

6. The method of claim 1, wherein, The said throwing control subsystem includes: a fixed plate (7), a signal adapter (8), a slide rail (9), a throwing device (10), a first hanging rope (11), a second hanging rope (12), a third hanging rope (13), and a fourth hanging rope (14); The fixed plate (7) is installed at the bottom of the body of the unmanned aerial vehicle (2) to fix the signal adapter (8); the signal adapter (8) is fixed on the bottom plate of the fixed plate (7); two slide rails (9) are fixed on the two sides of the bottom plate of the signal adapter (8); each end of each slide rail (9) is connected with a throwing device (10), that is, there are four throwing devices in total; The signal adapter (8) and the throwing device (10) are connected through a signal line, and a push rod (41) is arranged in the throwing device (10); the signal adapter (8) is used for receiving and processing operation instructions sent by the remote controller (3), and sending the operation instructions to the throwing device (10) through the signal line to control the push rod (41) in the throwing device (10) to move forward and backward; The first hanging rope (11), the second hanging rope (12), the third hanging rope (13), and the fourth hanging rope (14) are sequentially hung on the push rods (41) of the four throwing devices (10); the first hanging rope (11), the second hanging rope (12), the third hanging rope (13), and the fourth hanging rope (14) are respectively connected with the four top corners of the top plate of the oil tank (1); when the push rod (41) moves backward, the hanging ropes are detached from the push rod (41), realizing the throwing of the oil tank (1); By adjusting the lengths of the four hanging ropes, the included angle between the suspended oil tank (1) and the horizontal ground is controlled.

7. The method of claim 1, wherein, The said hovering control subsystem includes: a body camera (4) arranged on the unmanned aerial vehicle (2), a laser emitter (5), and a positioner (6). The body camera (4) is used for acquiring the flight field of view; the laser emitter (5) is used for measuring the flight height of the unmanned aerial vehicle (2); the positioner (6) is used for measuring the height of the oil tank (1) from the ground; and the flight of the unmanned aerial vehicle (2) is controlled through the remote controller (3).

8. A method of simulating a high speed drop test of an aircraft fuel tank as defined in claim 1, wherein, In step S1, the flight height of the UAV (2) is calculated as follows: wherein, is the drop velocity of the tank (1) required by the test, in m / s ; is the gravitational acceleration, with a value of 9.81 .

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