Aircraft lightweight dynamic model based on magnetic levitation flight wind tunnel

Abstract

The invention relates to the technical field of wind tunnel tests, in particular to an aircraft lightweight dynamic model based on a maglev flight wind tunnel, which comprises a first section module, a second section module and a third section module which are connected in sequence. Wherein the first section module is used for simulating a tip part of an aircraft, and discontinuous skin layers cover the outer sides of the first section module, the second section module and the third section module; the invention provides a'discontinuous split-level model design 'for a'dynamic body and static wind' magnetic levitation flight wind tunnel model so as to ensure the overall rigidity of the model while realizing the light weight of the model, thereby meeting the test requirements under acceleration impact (the maximum acceleration / deceleration of a magnetic levitation platform is about 20g).

Description

Technical Field

[0001] The invention relates to the technical field of wind tunnel testing, and in particular to a lightweight dynamic model of an aircraft based on a magnetic levitation flight wind tunnel. Background Art

[0002] Wind tunnel testing is one of the important means to understand the performance of aerospace vehicles and reduce the risk and cost of aircraft development. Traditional wind tunnels mostly use the "static body and dynamic wind" mode, where the model is static and the airflow is moving. The acceleration and deceleration impact is small, and the lightweight design (such as the fiberglass-aluminum alloy composite structure of patent CN106840597A) can effectively reduce inertial vibration interference.

[0003] However, the maglev flying wind tunnel uses vacuum tube magnetic levitation technology to realize the "body moving wind static" dynamic model test, and the model will move at high speed (acceleration / deceleration up to 20g). Specifically, the maglev flying wind tunnel is a new concept aerodynamic test and research facility proposed by combining vacuum tube magnetic levitation technology with the principle of dynamic model test. It can simulate the physical process of aerospace vehicles and high-speed trains, and innovatively construct a "body moving wind static" test environment close to the real flight state, with the characteristics of fast changing Mach number, wide speed range, wide Reynolds number, low noise and low turbulence.

[0004] Due to the constraints of the length of the test section and the maximum operating speed of the model, during the dynamic model force measurement test of the maglev flight wind tunnel, the maglev platform will generate a large acceleration / deceleration (its maximum operating acceleration can reach 20g), and the model and the supporting device will be subjected to a large transient impact load, thereby stimulating the vibration of the model-balance-support system and the maglev platform. This vibration will inevitably produce transient interference to the output of the force measuring balance. In order to obtain accurate dynamic model aerodynamic load data, it is necessary to effectively decouple and separate the aerodynamic load and inertial load borne by the model. Therefore, the accuracy of inertial load measurement directly affects the accuracy of wind tunnel test data, especially the measurement accuracy of resistance. Through the lightweight design of the model, the proportion of the dynamic model inertial load in the design range of the balance can be greatly reduced, effectively improving the sensitivity of the balance, thereby improving the accuracy of the force measurement test.

[0005] The above-mentioned lightweight solution (CN106840597A) is designed for traditional wind tunnels with relatively small acceleration and deceleration shocks, and can still meet the strength requirements of the model; however, its frame load-bearing structure has at least the following deficiencies in the "body dynamic wind static" maglev flight wind tunnel test with acceleration and deceleration of up to 20g: the specific strength / specific stiffness of fiberglass and aluminum alloy is difficult to meet the dynamic stability under high-speed impact; it is impossible to take into account both lightweight and stiffness requirements.

[0006] Therefore, there is an urgent need for a dynamic model that can simultaneously ensure the lightness and rigidity of the model under high-speed impact. Summary of the invention

[0007] The present invention aims to provide a lightweight dynamic model of an aircraft based on a maglev flight wind tunnel, to partially solve or alleviate the above deficiencies in the prior art, and to ensure the overall rigidity and strength of the model while meeting the requirements of model lightweighting.

[0008] To solve the above-mentioned technical problems, the present invention specifically adopts the following technical solutions: A lightweight dynamic model of an aircraft based on a maglev flight wind tunnel, comprising: A first-stage module, a second-stage module, and a third-stage module connected in sequence, wherein the first-stage module is used to simulate the pointed part of the aircraft, and the outer sides of the first-stage module, the second-stage module, and the third-stage module are covered with a discontinuous skin layer; The second-stage module includes at least one longitudinal bracket arranged along the longitudinal direction of the aircraft, and at least one transverse bracket arranged crosswise with the longitudinal bracket. The longitudinal bracket and the transverse bracket form a hollow space inside the skin layer; a first connection part is provided at the second end of the second-stage module; The third-stage module includes a support frame. An installation space is provided along the length direction at the center of the support frame, and at least one hollow hole is provided on each side of the installation space; a second connection part is provided at the first end of the support frame, and an internal passage for accommodating a tail support rod is provided at the second end of the installation space; A first raised edge is provided at the second end of the second-stage module, and a second raised edge is provided at the first end of the third-stage module; When the second connection part is inserted into the first connection part for fixation, and the tail support rod is inserted into the internal passage for fixation, the first raised edge and the second raised edge are attached to form a spacer layer, and the discontinuous skin layer is distributed on both sides of the spacer layer to cover the second-stage module and the third-stage module, and the first-stage module, the second-stage module, the third-stage module, and the tail support rod are connected into a whole.

[0009] As an improvement, a force sensor and an acceleration sensor are further provided at the front end of the installation space.

[0010] As an improvement, a detachable cover plate is provided on the outer periphery of the installation space, and an operation hole corresponding to the cover plate is provided on the skin layer.

[0011] As an improvement, at least one support protrusion is provided on the surface of the support frame, at least one support hole cooperating with the support protrusion is provided on the skin layer, and the edge of the support hole surrounds and fits the edge of the support protrusion.

[0012] As an improvement, the lateral bracket at least includes a first cross beam and a second cross beam with different heights, and the first cross beam and the second cross beam are staggered.

[0013] As an improvement, a connecting piece is arranged between the force measuring sensor and the tail support rod. When connecting pieces with different sizes are installed in the installation space, the installation space can accommodate force measuring sensors with different sizes.

[0014] As an improvement, the hollow hole is in a triangular shape.

[0015] As an improvement, the material of the first section module is aluminum alloy.

[0016] As an improvement, a gap is left between the tail support rod and the skin layer of the third section module.

[0017] As an improvement, it further includes: an arc-shaped guide rail, and a plurality of first installation positions are arranged along the length direction of the arc-shaped guide rail; a guide rail connecting piece, the first end of the guide rail connecting piece is provided with an installation hole for being clamped into the tail support rod, and a second installation position corresponding to the first installation position is arranged on the guide rail connecting piece.

[0018] Beneficial technical effects: Traditional wind tunnels adopt the test mode of "body static and air dynamic", that is, the model remains relatively static, and the movement speed of the model is simulated by air flow. However, the test mode of "body static and air dynamic" is opposite to the real flight situation of the aircraft, and it ignores the influence of continuous speed change (a = dv / dt). Therefore, it is difficult to accurately reflect the real force state of the aircraft during high-maneuver flight. The maglev flight wind tunnel operates in the way of "body dynamic and air static", and has natural advantages in researching and solving dynamic aerodynamics problems at the speed domain connection of "low speed - high speed", and can more truly simulate the dynamic characteristics of the aircraft, which has an important role in further improving the air dynamic test equipment system of our country.

[0019] Completely different from the design concept in traditional wind tunnel tests, which uses an "integrated" design (an integrated frame load-bearing structure and an integrated model shell) to ensure the model strength of the frame structure, this application provides a "discontinuous stepped model design" for the maglev flight wind tunnel model with "moving object and static wind" to ensure the overall rigidity and strength of the model while achieving model lightweighting, so as to meet the test requirements under acceleration impact (the acceleration / deceleration of the maglev platform is about 20g). Among them, through the lightweight design of the model, the proportion of the inertial load of the moving model in the design range of the balance can be greatly reduced, effectively improving the balance sensitivity and thus improving the measurement accuracy of the force measuring sensor. Moreover, the internal modules and the external skin layer of this model both adopt discontinuous designs. At the same time, stepped designs are adopted both inside the modules and between the modules and the skin, enabling the model to be easily disassembled and replaced while achieving the strength effect of the "integrated setting" in the existing technology.

[0020] Specifically, this model adopts a discontinuous three-section design, with the internal frame designed as three independent modules. The materials of the vulnerable parts (such as the tip) and other parts (such as the second section module) in the three modules are differentiated. Independent skin layers are respectively covered on the three section modules. After one part (especially the tip) is damaged, the damaged part can be quickly replaced, and for other parts, especially the third section module that bears the core components, it can be reused, thus reducing the model cost. Further, the second section module and the third section module adopt a hollowed-out stepped design, which can reduce the model weight while ensuring the connection strength between the modules and between the modules and the skin. For example, the discontinuous second section module and the third section module are seamlessly connected through an intermediate layer step, enabling the overall model to achieve the strength effect of the "integrated design" while ensuring the signal conduction efficiency in the three metal modules; another example is that the stepped first cross beam and second cross beam effectively support the skin layer at different positions in the model length direction, and the support protrusions with a stepped design from the support frame effectively limit the position of the skin layer, thus ensuring the model lightweight while ensuring the strength and disassembly convenience of the model. BRIEF DESCRIPTION OF THE DRAWINGS In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts do not necessarily draw according to the actual proportion. Obviously, the following described drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts.

[0021] Figure 1This is the overall structure diagram of the moving model in the embodiment of the present invention; Figure 2 This is the partial structure diagram of the moving model in the embodiment of the present invention; Figure 3 This is the schematic diagram of the second segment module in the moving model of the embodiment of the present invention; Figure 4 This is the schematic diagram of the third segment module in the moving model of the embodiment of the present invention; Figure 5 This is the partial structure diagram of another angle of the moving model in the embodiment of the present invention; Figure 6 This is another partial schematic diagram of the moving model in the embodiment of the present invention; Figure 7 This is another schematic diagram of the second segment module in the moving model of the embodiment of the present invention; Figure 8 This is the schematic diagram of the guide rail part of the moving model in the embodiment of the present invention; Figure 9 This is the structural schematic diagram of the guide rail connecting part of the moving model in the embodiment of the present invention.

[0022] Summary of reference numeral identification: 10, the first segment module; 20, the second segment module; 21, the longitudinal bracket; 22, the transverse bracket; 221, the first cross beam; 222, the second cross beam; 23, the first connecting part; 24, the first raised edge; 30, the third segment module; 31, the installation space; 32, the internal channel; 33, the second raised edge; 34, the support protrusion; 311, the support frame; 312, the second connecting part; 313, the cover plate; 40, the tail support rod; 50, the arc guide rail; 51, the first installation position; 60, the guide rail connecting part; 61, the second installation position; 70, the force measuring sensor; 80, the acceleration sensor; 90, the connecting part; 100, the hollow hole; 101, the first hole; 102, the second hole; 103, the third hole; 104, the force distribution plane. Detailed implementation manners

[0023] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0024] In this article, suffixes such as "module", "component" or "unit" used to represent elements are only for the convenience of explaining the present invention, and they have no specific meaning themselves. Therefore, "module", "component" or "unit" can be used interchangeably.

[0025] In this text, terms such as "upper", "lower", "inner", "outer", "front", "rear", "one end", "the other end", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0026] In this text, unless otherwise clearly specified and defined, terms such as "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, and can also be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In this text, "a plurality of" means two or more, that is, it includes two, three, four, five, etc.

[0028] As used in this specification, the term "about" typically represents + / - 5% of the value, more typically + / - 4% of the value, more typically + / - 3% of the value, more typically + / - 2% of the value, even more typically + / - 1% of the value, and even more typically + / - 0.5% of the value.

[0029] In this specification, certain embodiments may be disclosed in a format within a certain range. It should be understood that this description of "within a certain range" is only for convenience and brevity and should not be construed as a rigid limitation on the disclosed range. Therefore, the description of the range should be considered to have specifically disclosed all possible sub-ranges and individual numerical values within this range. For example, the description of the range 1 to 6 should be regarded as having specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and individual numbers within this range, such as 1, 2, 3, 4, 5, and 6. The above rules apply regardless of the breadth of the range.

[0030] Example 1: A lightweight dynamic model of an aircraft based on a maglev flight wind tunnel, see Figures 1-9 , including: A first-stage module 10, a second-stage module 20, and a third-stage module 30 that are connected in sequence, wherein the first-stage module 10 is used to simulate the pointed part of the aircraft, and the outer sides of the first-stage module 10, the second-stage module 20, and the third-stage module 30 are covered with a discontinuous skin layer; where "discontinuous" means that a segmented multi-segment structure is combined in a direct or indirect connection manner.

[0031] See Figure 3 , the second-stage module 20 includes: at least one longitudinal bracket 21 arranged along the longitudinal direction of the aircraft, and at least one transverse bracket 22 arranged crosswise with the longitudinal bracket 21, and the longitudinal bracket 21 and the transverse bracket 22 form a hollow space inside the skin layer; a first connecting portion 23 is provided at the second end of the second-stage module 20. Wherein, "longitudinal" includes the direction pointed by the line connecting any point on the first end of the second-stage module to any point on its second end, that is, the overall trend of the longitudinal direction is towards the length direction of the aircraft, but it is not necessarily parallel to its length direction; "transverse" is that the overall trend is towards the width direction of the aircraft and forms a certain angle with the longitudinal direction. It should be noted that both the longitudinal bracket 21 and the transverse bracket 22 can be curved brackets with a certain curvature.

[0032] See Figure 4 , the third-stage module 30 includes: a support frame 311, an installation space 31 is provided along the length direction at the center of the support frame 311, and at least one hollow hole is provided on each side of the installation space 31, that is, a plurality of hollow holes are provided on the support frame 311, and the plurality of hollow holes are respectively located on both sides of the installation space 31 to reduce the overall mass of the model; a second connecting portion 312 is provided at the first end of the support frame 311, and an internal channel 32 for accommodating a tail support rod is provided at the second end of the installation space 31; wherein, the third-stage module 30 is both the installation foundation for each component of the model and the load-bearing main body. The material of the third-stage module 30 is selected as 7075-T6 aluminum alloy. When designing the third-stage module 30, it is based on the coincidence of the moment reference center of the model and the force decomposition center of the force sensor 70 (preferably a six-component force sensor), and considering the disassembly and assembly of the force sensor 70 and the acceleration sensor 80, the front and rear fuselage separation surfaces (that is, the connection surface between the second-stage module 20 and the third-stage module 30) are reasonably selected.

[0033] When the second connecting portion 312 is inserted into the first connecting portion 23 for fixation, and the tail support rod 40 is inserted into the internal channel 32 for fixation, the first-stage module 10, the second-stage module 20, the third-stage module 30, and the tail support rod 40 are connected into a whole.

[0034] In some embodiments, a first raised edge 24 is provided at the second end of the second section module 20, and a second raised edge 33 is provided at the first end of the third section module 30; when the second connecting portion 312 is inserted into the first connecting portion 23 for fixation, the first raised edge 24 and the second raised edge 33 are fitted to form a spacer layer, and the discontinuous skin layer is distributed on both sides of the spacer layer to cover the second section module 20 and the third section module 30, that is, the skin layers on the second section module 20 and the third section module 30 do not directly contact. During the disassembly process, by disassembling the first connecting portion 23 and the second connecting portion 312, the two can be easily separated, and the spacer layer can compensate for the force transmission path between the second section module and the third section module designed in sections, avoiding the existence of a gap between the two and affecting the force transmission, thereby affecting the test results.

[0035] In some embodiments, the first raised edge 24, the second raised edge 33, and the skin layer have the same thickness, so as to form a "continuous surface" with the same height between the second section module and the third section module, so as to reduce the resistance and achieve the effect of "integrated design".

[0036] In this article, the first end refers to the end close to the pointed part, and the second end refers to the end close to the tail support rod 40. Figure 2 The direction of the arrow a in the figure is the direction from the first end to the second end.

[0037] The model with the above structure adopts a discontinuous stepped three-section design, divides the internal frame according to functional sections (including the vulnerable part at the tip, the load-bearing section, and the test section for installing components such as sensors, where the vulnerable part, the load-bearing section, and the test section correspond to the first section module 10, the second section module 20, and the third section module 30 respectively), and designs them as three independent modules. The three modules (the first section module 10, the second section module 20, and the third section module 30) are connected in sequence, and at least a part of the skin layers on the three modules are installed at intervals, and a "continuous" smooth surface similar to an integral structure is formed between the stepped spacer layer and the skin layer. While facilitating the disassembly and assembly of multiple modules (preventing adhesion between the skins), it can also ensure the strength of the overall model. That is, after a part of the model is damaged by high-speed impact, this model can disassemble and replace the damaged module separately, and at the same time, it can achieve the model strength of the "integral design" in the prior art.

[0038] In some specific embodiments, the model structure is divided into a front fuselage skin, a rear fuselage skin, a nose tip (i.e., the first section module 10), a front fuselage skeleton (i.e., the second section module 20), a rear fuselage skeleton (i.e., the third section module 30), a front-rear fuselage connector, a cover plate 313, a six-component force sensor 70, a model-force sensor 70 connector, a force sensor 70-strut connector, a tail support strut, a strut-rail connector 60, an arc-shaped rail 50, acceleration sensors 80 (a total of 5), an angle measurement block, φ12 threaded pins, positioning pins, and screws.

[0039] In some embodiments, a first connection portion 23 is formed by inwardly recessing the second end of the second section module 20, and a second connection portion 312 is formed by outwardly protruding the first end of the third section module 30. Corresponding positioning holes (such as pin holes) are provided on the first connection portion 23 and the second connection portion 312, respectively.

[0040] In some embodiments, the second connection portion 312 includes, but is not limited to, one of a cylindrical shape, a cuboid, or a polyhedron.

[0041] In some embodiments, the skin layer is composed of a carbon fiber composite material. Specifically, the skin layer can adopt a carbon fiber + PMI (polyacrylamide) foam sandwich structure, that is, the skin layer is divided into three layers. The inner and outer layers are made of carbon fiber materials, and the middle layer is filled with foam, so as to achieve the effect of light weight and high strength.

[0042] In some embodiments, the thickness range of the skin layer is 2 mm to 3 mm, the thickness range of the carbon fiber in the outer and inner layers is 0.5 mm to 1 mm, and the thickness of the foam sandwich is about 1 mm. The skin layer adopts a low-cost and high-efficiency VARI (vacuum resin infusion) molding process, with no need for painting on the surface, and a gel coat layer is laid, fully demonstrating the natural color of the carbon fiber texture, improving the accuracy and aesthetics of the model external surface, and the surface accuracy is less than 0.2 mm. Regarding the assembly problem between the carbon fiber skin and the internal load-bearing skeleton, a one-time positioning and one-piece forming technology is adopted to achieve precise assembly of the internal skeleton and the carbon fiber composite skin. The connection interface between the carbon fiber skin and the metal parts adopts a bonding solution, effectively avoiding damage to the connection interface.

[0043] In some embodiments, it further includes a force sensor (preferably a six-component force sensor 70) and acceleration sensors 80 (preferably 5) disposed at the front end of the installation space 31.

[0044] In some embodiments, a connecting member 90 is provided between the force measuring sensor 70 and the tail support rod 40. When connecting members 90 of different sizes are installed in the installation space 31, the installation space 31 can accommodate force measuring sensors 70 of different sizes. That is, the connecting member 90 is located at the middle position of the installation space 31, and its front end is used to fix the force measuring sensor 70. By changing the size of the connecting member 90, the length of the installation space 31 at the front end of the connecting member 90 can be changed, so as to adapt to force measuring sensors 70 of different sizes.

[0045] In some embodiments, a cover plate 313 is detachably provided on the outer periphery of the installation space 31, and an operation hole corresponding to the cover plate 313 is provided on the skin layer. In some specific embodiments, the top of the installation space 31 has an angle measurement platform, and the cover plate 313 covers above the angle measurement platform. After disassembling the cover plate 313, the attitude angle of the model and the installation angle of the force measuring sensor 70 can be accurately measured by an optical inclinometer, which is convenient for the installation of the model and the force measuring sensor 70 before the test.

[0046] In some embodiments, a metal edge sealing is provided on the outer periphery of the installation space, and the cover plate is located within the metal edge sealing. The metal edge sealing is used to separate the cover plate from the skin, that is, the skin and the cover plate do not directly contact, so as to avoid the force being transmitted to the skin and dispersed.

[0047] In some embodiments, at least one support protrusion 34 is provided on the surface of the support frame 311, and at least one support hole matching with the support protrusion is provided on the skin layer. The edge of the support hole is surrounded and attached to the edge of the support protrusion 34. By performing a stepped design on the support frame 311 of the third-stage module 30 (that is, providing support protrusions 34 with different thicknesses on the support frame 311), the skin layer can be further connected to the support frame 311 at different levels through the support protrusion 34, thereby enhancing the connection strength between the two.

[0048] In some embodiments, the transverse bracket 22 at least includes a first cross beam 221 and a second cross beam 222 with different heights, and the first cross beam 221 and the second cross beam 222 are staggered. Among them, the staggered distribution means that the first cross beam 221 and the second cross beam 222 are staggered in the length direction of the aircraft, and they are parallel but located at different positions of the aircraft. For example, the distance between the first cross beam 221 and the third-stage module is greater than the distance between the second cross beam 222 and the third-stage module. By providing multiple cross beams with a stepped distribution, the skin layer can be effectively supported at different positions in the length direction of the model, further enhancing the bearing capacity of the model.

[0049] In some embodiments, the width and / or cross-sectional area of the aircraft gradually increase from its first end to its second end, such that the overall shape of the aircraft is triangular, that is, the widths and / or cross-sectional areas of the first module, the second module, and the third module gradually increase, and the width and cross-sectional area of the second end of the first module are the same as those of the first end of the second module, and the width and cross-sectional area of the second end of the second module are the same as those of the first end of the third module. The three modules are smoothly transitioned and connected.

[0050] In some embodiments, the first module 10 and the third module 30 can be made of aluminum alloy material (such as 7075-T6 aluminum alloy), the second module 20 can be made of alloy structural steel (such as 30CrMnSiA), and the three modules are separately adhesively connected to their corresponding skin layers to form three independent modules with skin layers. That is, based on the above multi-module non-continuous staggered layer design, the present application further differentiates the materials of the multiple modules, that is, making them form a "weak-strong-weak" sandwich-type load-bearing material arrangement, so that the model has a better bearing capacity distribution, which can not only meet the rapid disassembly requirements between the modules, but also ensure the overall synergistic effect.

[0051] In some embodiments, the hollow hole 100 is in a triangular-like shape. Herein, the "triangular-like shape" means that the overall shape of the hollow hole is triangular, but two of the angles of the triangle are chamfered, and the other angle is cut to form a relatively short force distribution plane, and both ends of the force distribution plane are chamfered, and there are no sharp corners inside the entire hollow hole. To form a stable structure, further improve the stability of the second module 20 and the third module 30 with the hollow design, and optimize the force transmission path. Specifically, the "triangular-like shape" hollow hole can disperse stress, especially suitable for delta-wing aircraft. During the flight of a delta-wing aircraft, the resistance gradually conducts from its first end to its second end. In this process, stress concentration is particularly likely to occur. For an aircraft with the above structure, its force distribution plane can effectively distribute the force from the tip (first end) of the aircraft and conducted through the second end module to the entire third module, preventing damage caused by stress concentration.

[0052] In some embodiments, refer to Figure 4The hollow hole 100 includes a first hole 101, a second hole 102 and a third hole 103 which are sequentially arranged from the first end to the second end of the third section module 30. The force distribution plane 104 of the first hole 101 is located at the first end of the third section module 30, the force distribution plane 104 of the second hole 102 is located at the side of the third section module, and the force distribution plane 104 of the third hole 103 is located at the second end of the third section module 30. The three holes can respectively disperse the resistance from the first end, the side and the second end of the third section module 30, and distribute the force to the third section module 30 as evenly as possible, thereby further ensuring the strength of the third section module which has both load-bearing and component-bearing functions.

[0053] That is to say, completely different from the traditional indiscriminate "integrated" design, the present application actually provides a high-strength lightweight dynamic model of an aircraft that optimizes the force conduction path and divides the functional segments, which is particularly suitable for delta-wing aircraft. Specifically, the front end of the aircraft has extremely high requirements for force conduction, that is, the resistance generated at the tip during flight needs to be transmitted to the sensor as much as possible for collection, and after the force is transmitted to the rear end sensor and collected, it needs to be dispersed to various areas as much as possible to avoid damage to the aircraft caused by continuous force impact; the present application uses the first and second modules of the partition design as the main force conduction area, and distinguishes the two from the material, which can ensure the strength of the force conduction area, and at the same time can partially replace the damaged part; and the third module is used as a force decomposition area, and its force distribution plane can effectively distribute the force from the tip of the aircraft (the first end) and after being transmitted through the second end module to the entire third module, to prevent stress concentration from causing damage to it.

[0054] In some embodiments, a gap is left between the tail support rod 40 and the skin layer of the third section module 30, the height of the gap ranges from 3mm to 5mm, and the tail support rod 40 is also not in direct contact with the inner surface of the third section module 30 (that is, the internal shape surface of the third section module 30) to ensure that the force measurement data is more reliable.

[0055] In some embodiments, the second end of the third section module is W-shaped, that is, the second end of the third section module is bent four times from one end to the other, forming a V-shaped structure at both ends of the support rod, and there is a filling gap (preferably 3mm-5mm) between the second end of the third section module and this part of the skin, and the filling gap is filled with a filler (such as foam), that is, this scheme performs a lightweight load-bearing design for the second end of the third section module, while ensuring its strength while reducing the overall weight of the aircraft.

[0056] In some embodiments, see Figure 8 and Figure 9, further comprising: an arc-shaped guide rail 50, wherein a plurality of first mounting positions 51 (such as pin holes) are arranged along the length direction of the arc-shaped guide rail 50; a guide rail connecting member 60, a mounting hole is arranged at the first end of the guide rail connecting member 60 for clamping the tail support strut, and a second mounting position 61 (such as a pin hole) corresponding to the first mounting position 51 is arranged on the guide rail connecting member 60. By adopting the tail support + arc-shaped guide rail 50 manual variable angle of attack structure, the angle of attack can be adjusted and changed every 2° within the range of 0° to 12°. The overall structural design and the selection of part materials are reasonable, the processing technology is mature, the disassembly and assembly of parts are convenient, the positioning is reliable, and the results of the rigidity and strength check meet the test use requirements.

[0057] In some specific embodiments, the material of the arc-shaped guide rail 50 is 30CrMnSiA alloy steel, and the mass is about 8.5 kg. It can rotate around the pitch axis of the model moment reference center within the range of 0° to 16° as a whole; 9 φ12 positioning pin holes can be designed on it to realize the rotation of the model within the range of -2° to 16°, and at the same time, 10 M6 threaded holes are designed, with an interval of 2° each. Each angle is positioned by a φ12 cylindrical pin and fixed by 4×M6 screws. The next angle needs to use 2 threaded holes of the previous angle, so as to realize the manual change of the model angle of attack every 2° within the range of 0° to 12°. After the arc-shaped guide rail 50 and the mounting base plate of the inertial mechanical decoupling device are positioned through 2×φ10 positioning pin holes, they are fixed by 6×M8 screws and then installed on the magnetic levitation platform. The arc-shaped guide rail 50 reserves space for the cable layout of the force sensor 70 and the acceleration sensor 80.

[0058] In some embodiments, a wire routing hole is arranged inside the tail support strut. For example, the tail support rod 40 adopts a hollow design, and the wires of the sensors are led out through its internal channel 32.

[0059] In summary, it is completely different from the design idea in the prior art of using an "integrated" design (an integrated frame load-bearing structure and an integrated model shell) to ensure the model strength of the frame structure. The present application provides a "non-continuous stepped model design" for the "body moving and wind static" magnetic levitation flight wind tunnel model to ensure the overall stiffness of the model while ensuring the lightweight of the model, so as to meet the test requirements under acceleration impact (the acceleration / deceleration of the magnetic levitation platform is about 20g). Among them, the internal modules and the external skin layer of the present model both adopt non-continuous designs. At the same time, stepped designs are adopted both inside the modules and between the modules and the skin, so that the model is easy to disassemble and replace while achieving the strength effect of "integrated setting" in the prior art.

[0060] It should be noted that, in this article, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article or device. Without further limitations, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including such element.

[0061] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative rather than restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the purpose of the present invention and the scope protected by the claims. All of these fall within the protection scope of the present invention.

Claims

1. A lightweight dynamic model of an aircraft based on a maglev flight wind tunnel, characterized in that, Including: A first-stage module (10), a second-stage module (20), and a third-stage module (30) connected in sequence, wherein the first-stage module (10) is used to simulate the pointed part of the aircraft, and the outer sides of the first-stage module (10), the second-stage module (20), and the third-stage module (30) are covered with a discontinuous skin layer; The second-stage module (20) includes: at least one longitudinal bracket (21) arranged along the longitudinal direction of the aircraft, and at least one transverse bracket (22) arranged crosswise with the longitudinal bracket (21), and the longitudinal bracket (21) and the transverse bracket (22) form a hollow space inside the skin layer; a first connecting portion (23) is provided at the second end of the second-stage module (20); The third-stage module (30) includes: a support frame (311), an installation space (31) is provided along the length direction at the center of the support frame (311), and at least one hollow hole (100) is provided on each side of the installation space (31); a second connecting portion (312) is provided at the first end of the support frame (311), and an internal passage (32) for accommodating a tail support rod is provided at the second end of the installation space (31); A first raised edge (24) is provided at the second end of the second-stage module (20), and a second raised edge (33) is provided at the first end of the third-stage module (30); When the second connecting portion (312) is inserted into the first connecting portion (23) for fixation, and the tail support rod (40) is inserted into the internal passage (32) for fixation, the first raised edge (24) and the second raised edge (33) are fitted to form a spacer layer, and the discontinuous skin layer is distributed on both sides of the spacer layer to cover the second-stage module (20) and the third-stage module (30), and the first-stage module (10), the second-stage module (20), the third-stage module (30), and the tail support rod (40) are connected into a whole.

2. The lightweight dynamic model of the aircraft based on the maglev flight wind tunnel according to claim 1, characterized in that, It further includes a force sensor (70) and an acceleration sensor (80) provided at the front end of the installation space (31).

3. The lightweight dynamic model of the aircraft based on the maglev flight wind tunnel according to claim 1, wherein A detachable cover plate (313) is provided on the outer periphery of the installation space (31), and an operation hole corresponding to the cover plate (313) is provided on the skin layer.

4. The lightweight dynamic model of the aircraft based on the maglev flight wind tunnel according to claim 1, wherein, At least one support protrusion (34) is provided on the surface of the support frame (311), and at least one support hole cooperating with the support protrusion (34) is provided on the skin layer, and the edge of the support hole surrounds and fits against the edge of the support protrusion (34).

5. The lightweight dynamic model of the aircraft based on the maglev flight wind tunnel according to claim 1, characterized in that, The transverse bracket (22) at least includes a first cross beam (221) and a second cross beam (222) having different heights, and the first cross beam (221) and the second cross beam (222) are staggered.

6. The lightweight dynamic model of the aircraft based on the maglev flight wind tunnel according to claim 2, wherein A connecting member (90) is provided between the force sensor (70) and the tail support rod (40), and when connecting members (90) with different sizes are installed in the installation space (31), force sensors (70) with different sizes can be accommodated in the installation space (31).

7. The lightweight dynamic model of the aircraft based on the maglev flight wind tunnel according to claim 1, characterized in that, The hollow hole (100) is triangular in shape.

8. The lightweight dynamic model of an aircraft based on a maglev flight wind tunnel according to claim 1, characterized in that The materials of the first section module and the third section module are aluminum alloy, and the material of the second section module is alloy steel.

9. The lightweight dynamic model of the aircraft based on the maglev flight wind tunnel according to claim 1, characterized in that, A gap is left between the tail support rod (40) and the skin layer of the third section module (30).

10. The lightweight dynamic model of the aircraft based on the maglev flight wind tunnel according to claim 1, wherein Further included are: An arc-shaped guide rail (50), and a plurality of first installation positions (51) are arranged along the length direction of the arc-shaped guide rail (50); A guide rail connecting member (60), the first end of the guide rail connecting member (60) is provided with a mounting hole for clamping into the tail support rod, and a second installation position (61) corresponding to the first installation position (51) is arranged on the guide rail connecting member (60).

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