Controllable mass center stamping fuel oil system for small-sized large-maneuvering aircraft and use method of controllable mass center stamping fuel oil system

Abstract

The invention discloses a controllable mass center stamping fuel oil system for a small-sized large-maneuvering aircraft, which comprises a pressurizable vacuum fuel oil tank (1), a pressurizing air entraining pipeline (2), an oil supply pipeline (3) and a fixing unit, the pressurizable vacuum fuel oil tank (1) comprises an oil bag (11) and a plurality of air bags (12), each air bag (12) is connected with the oil bag (11) but not communicated with the oil bag (11), and the oil bag (11) is communicated with the pressurizing air entraining pipeline (2). The pressurizing air entraining pipeline (2) is communicated with each air bag (12), the oil bag (11) is connected with the engine (4) through the oil supply pipeline (3), and the fixing unit is used for fixing the pressurizing vacuum fuel tank (1) and enabling the gravity center of the pressurizing vacuum fuel tank (1) not to deviate. The pressurizable vacuum fuel tank is made of flexible materials, can be made into different shapes according to the structure of a cabin and is composed of the air bag and the oil bag, and in the using process, the air bag pressurizes and directionally extrudes the oil bag to form oil supply pressure.

Description

Technical Field

[0001] The present invention belongs to the technical field of aircraft fuel supply, and in particular relates to a controllable center of mass ramjet fuel system for a small and large maneuverable aircraft and a use method thereof. Background Art

[0002] Small and highly maneuverable aircraft have broad application prospects in the fields of modern military and aviation models. A flight action in which the flight state changes over time is called a maneuver. The larger the range of flight state changes and the shorter the time required to change the state, the better the maneuverability of the aircraft, but maneuvering flight will cause a large overload acceleration of the entire aircraft. Especially for highly maneuverable aircraft such as target missiles and suicide drones for military purposes, the flight overload is generally high. Frequent maneuvers of aircraft bring about random large maneuver overloads, which will cause huge and frequent displacement and shaking of the fuel in the cabin, directly causing random shifts in the center of gravity of the aircraft.

[0003] Conventional aircraft are equipped with multiple fuel tanks, and use a sequential fuel supply method to adjust and control the center of gravity offset of the fuel system. For large maneuvering aircraft, a reserve fuel tank is usually designed to ensure stable fuel supply to the engine during large maneuvers. This fuel system design usually leads to problems such as system complexity, increased weight, and increased remaining fuel.

[0004] Small aircraft generally use soft vacuum fuel tanks to solve the problem of continuous fuel supply caused by large maneuvers. Fuel is added to a sealed soft fuel tank made of rubber / TPU material, and the gas therein is completely discharged. The fuel tank gradually shrinks as the fuel is supplied to the engine. For aircraft with large maneuvering flight requirements, jet engines are usually used as aircraft power devices. This power source usually has high requirements for fuel pressure and requires the fuel system to use bleed air pressurization. For example, the invention patent CN106218907A (a flying object fuel tank and fuel supply system) divides the fuel tank into two areas, separates the fuel storage tank from the pressurized cabin, and supplies fuel from a fuel storage tank without air; another example is the utility model patent CN212656905U (an aviation fuel supply system) uses the cruise fuel tank cavity and the maneuvering fuel tank cavity for fuel supply, and adjusts the fuel supply source through a solenoid valve. The existing pressurized soft fuel tanks have the following problems: 1. The pressurized soft fuel tanks all adopt an oil supply method that isolates air and fuel. The inside of the fuel tank is not visible. Due to structural limitations, the air in the oil storage tank cannot be completely discharged, which will affect flight safety during maneuvering flight; 2. Most of them adopt simple configurations such as hemispherical and rectangular shapes, which cannot meet the requirements of special-shaped fuel tanks in the design of existing aircraft; 3. The pressurization process requires carrying an air source or drawing air from the engine, which has a complex structure and increases weight; 4. The problem of fixing the center of gravity of the fuel tank has not been solved, which affects flight controllability, especially affecting flight safety during maneuvering flight.

[0005] For small and highly maneuverable aircraft, conventional fuel system design is complex, heavy, and has too much residual fuel. The vacuum soft fuel tank system is affected by the large maneuvers, and its life is difficult to guarantee, and it is impossible to achieve air bleed pressurization. Therefore, the traditional fuel tank design cannot meet the use requirements. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a controllable center of mass ramjet fuel system for a small large maneuverable aircraft and a method of using the same. The technical solution adopted by the present invention is as follows:

[0007] A controllable mass center ramjet fuel system for a small large maneuverable aircraft comprises a pressurized vacuum fuel tank, a pressurized air bleed pipeline, a fuel supply pipeline and a fixing unit. The pressurized vacuum fuel tank comprises an oil bag and a plurality of air bags, each of which is connected to the oil bag but not in communication with the oil bag.

[0008] The pressurized air bleed pipeline is connected to each air bag, the oil bag is connected to the engine through the oil supply pipeline, and the fixing unit is used to fix the pressurized vacuum fuel tank and prevent the center of gravity of the pressurized vacuum fuel tank from shifting.

[0009] Furthermore, the oil bag is connected to a fuel pipeline through an oil nozzle and supplies the fuel to the engine, and the air bag is connected to a pressurized air bleed pipeline through an air nozzle.

[0010] Furthermore, the interface between the oil bladder and the airbag and the outer end surface of the airbag are thickened wall surfaces, using a thickened TPU film of a first thickness, and the contraction surface of the oil bladder and the airbag are ultra-thin wall surfaces, using a flexible TPU film of a second thickness, and the first thickness is greater than the second thickness.

[0011] Furthermore, the oil nozzle is located at the center of the oil bag contraction surface, and the air nozzle is located on the thickened wall surface of the outer end of the air bag.

[0012] Furthermore, it also includes a refueling pipeline and a pipeline tee, wherein the pipeline tee is arranged on the oil supply pipeline, and the refueling pipeline is connected with the oil supply pipeline through the pipeline tee.

[0013] Furthermore, the fixing unit includes a plurality of buckles, and the plurality of buckles are located outside the center of the oil bag contraction surface and are fixedly connected to the inner bulkhead of the aircraft.

[0014] Furthermore, the first thickness is 1-2 mm, and the second thickness is 0.3-0.8 mm.

[0015] Furthermore, there are two airbags, which are symmetrically arranged on both sides of the oil bag.

[0016] Furthermore, the pressurizable vacuum fuel tank completely fits the fuel tank bulkhead and occupies the fuel tank space of the aircraft.

[0017] A method for using the controllable center of mass ramjet fuel system for a small large maneuverable aircraft according to the above,

[0018] When refueling, the airbag is vented to the atmosphere, and the fuel pump fills the fuel into the oil bag through the refueling pipeline. At this time, the oil bag expands to both sides, and the oil bag squeezes the airbag to discharge the air in the airbag. When the oil bag is fully expanded, the airbag is fully compressed, and the air is completely discharged, the fuel filling is completed.

[0019] When supplying fuel to the engine, the airbag is pressurized by ram air through the boost air duct, the oil bag is squeezed by the airbag, the fuel pressure in the oil bag increases, and fuel is supplied to the engine through the fuel supply line. At this time, the oil bag shrinks toward the center, and the airbag continuously squeezes the oil bag. When the oil bag is completely contracted and the airbag is completely expanded, the fuel is completely exhausted.

[0020] Compared with the prior art, the advantages of the present invention include:

[0021] (1) The main body of the fuel tank adopts an integrated design of oil bladder and air bladder, which is easy to replace; (2) It adopts soft TPU material, which is transparent and visible, confirming that the gas in the oil bladder is completely exhausted; (3) The fuel tank has a variety of configurations and can be made into special shapes according to the shape of the oil tank, which can fully utilize the space of the oil tank and has good body fit; (4) The fuel tank adopts an oil bladder without air and an air bladder with air bleed and pressurized ventilation design, and the pressurized air bladder squeezes the oil bladder for pressurization, while having the pressurization effect of the air bleed and pressurized fuel tank and the ultra-low residual oil characteristics of the vacuum soft fuel tank; (5) The fuel tank adopts a thin-wall compression and thick-wall shape-keeping design. A fixed buckle is provided at the center of mass of the fuel tank to fix it to the inner wall of the fuel tank to ensure that the fuel tank is in a stable state during use. The center of mass is fixed and controllable; (6) The oil bag and the air bag can be independently made of thin-walled materials of the same thickness, and a thick wall is heat-sealed on the outside of the conformal wall, avoiding the heat-sealing process problems of TPU materials of different thicknesses, reducing the processing difficulty and improving the yield rate; (7) The soft fuel tank has a low boost drive pressure and is used in low-speed aircraft without engine bleed air. It can be bleed by the pitot tube or by using the dynamic pressure of the aircraft for boost, and has strong applicability; (8) Through structural design, the boost vent nozzle, the fuel supply nozzle and the corresponding pipelines are fixed to the wall of the oil tank and do not move with the deformation of the soft fuel tank, so as to ensure that the center of mass of the entire fuel system is fixed during flight maneuvers.

[0022] In addition to the features and advantages described above, the principles and other features and advantages of the present invention are further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a front view of the controllable center of mass ramjet fuel system for a small large maneuverable aircraft of the present invention.

[0024] Figure 2 A top view of a controllable center of mass ramjet fuel system for a small large maneuverable aircraft according to the present invention.

[0025] Figure 3 It is a stereoscopic diagram of the controllable center of mass ramjet fuel system for the small large maneuverable aircraft of the present invention.

[0026] Figure 4 This is a diagram of the refueling process.

[0027] Figure 5 Complete the picture for cheering.

[0028] Figure 6 This is a diagram of the oil supply process.

[0029] Figure 7 This is a diagram showing fuel depletion. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. The implementation of the present invention is described in detail below in conjunction with the specific embodiments.

[0031] Combination Figure 1-3 A controllable mass center pressurized fuel system for a small large maneuverable aircraft includes a pressurized vacuum fuel tank 1, a pressurized air bleed pipe 2, an oil supply pipe 3, and a plurality of fixed buckles 13. The pressurized air bleed pipe 2 is connected to each airbag 12, and the oil bag 11 is connected to the engine 4 through the oil supply pipe 3. The plurality of fixed buckles 13 are used to fix the pressurized vacuum fuel tank 1 and prevent the center of gravity of the pressurized vacuum fuel tank 1 from shifting. The fuel tank 1 completely fits the oil tank bulkhead and occupies the aircraft fuel tank space. The wall of the fuel tank is made of oil-resistant TPU film of varying thickness, the interface between the oil bag 11 and the air bag 12 and the end face of the air bag 12 are made of thickened TPU film with a thickness of 1 to 2 mm, and the contraction surface of the oil bag 11 and the air bag 12 is made of flexible TPU film with a thickness of 0.3 to 0.8 mm. There is only fuel and no air inside the oil bag 11, and there is only air and no fuel inside the air bag 12, and the two are not connected. The fixed buckles 13 are arranged around the center of the oil bag 11. When refueling, the fuel flows from the refueling pipeline 31 through the pipeline tee 32, and flows into the oil bag 11 through the fuel pipeline 3, and the oil bag 11 squeezes the air bag 12 to exhaust. The thickened wall surface 16 of the fuel tank 1 is a conformal wall surface, and the shape is made to be the same as the cross section of the fuel tank, and the ultra-thin wall surface 15 is a shrink wall surface.

[0032] The inlet of the boost air bleed pipe 2 points to the incoming flow direction. When the aircraft is flying, the outside air enters the boost air bleed pipe 2 from the incoming flow direction. According to the Bernoulli equation, the boost air bleed pipe 2 will produce The ram pressure (P is pressure, ρ is air density, and V is airspeed) inflates and pressurizes the airbag 12, and the airbag 12 squeezes the oil bag 11, pressurizes the fuel and supplies it to the engine 4.

[0033] The thickened wall of the fuel tank is the four walls on both sides of the oil bag 11 and the side of the air bag 12 (vertical direction). Its shape is not fixed and can be adjusted according to the cross-sectional shape of the oil tank during design. A nozzle 14 is set at the center of the oil bag 11 for filling fuel into the oil bag 11, and the oil bag 11 supplies fuel to the engine. The nozzle 13 is located at the center of the contraction surface of the oil bag 11, and its position does not change with the expansion / contraction of the oil bag 11 during the use of the fuel tank. An air nozzle 21 is set on each side of the two air bags 12, which is used to exhaust the air bags 12 when filling fuel, draw air and pressurize the air bags 12 when supplying fuel, and provide pressure from the air bags 12 to the oil bags 11. The air nozzle 21 is located on the end faces of both sides of the air bags 12, and its position does not change with the expansion / contraction of the air bags 12.

[0034] Combination Figure 4-5 When fuel is added, the airbag 12 is connected to the atmosphere, and the fuel pump adds fuel to the oil bag 11. At this time, the oil bag 11 expands to both sides, and the oil bag 11 squeezes the airbag 12 to discharge the air in the airbag 12. When the oil bag 11 is fully expanded, the airbag 12 is fully compressed, and the air is completely discharged, it appears Figure 3 The fuel filling is completed.

[0035] Combination Figure 6-7 When the fuel is supplied to the engine, the airbag 12 is pressurized by the ram air, and the fuel bag 11 is squeezed by the airbag 12, the fuel pressure in the fuel bag 11 increases, and the fuel is supplied to the engine 4. At this time, the fuel bag 11 shrinks toward the center, and the airbag 12 continuously squeezes the fuel bag 11. When the fuel bag 11 is completely contracted and the airbag 12 is completely expanded, the fuel is exhausted. Figure 4 Fuel exhaustion state. At this time, the fuel is completely exhausted.

[0036] During the fuel consumption process, the oil bladder 11 is squeezed by the air bladder 12 and fixed by the buckle 13, and its center is always fixed at the center of the fuel tank to ensure that the center of mass of the fuel does not change; at the same time, the oil bladder 11 is squeezed by the air bladder 12 to keep the fuel pressure in the oil bladder 11 consistent with the bleed air boost pressure; furthermore, the oil bladder 11 is isolated from the air, and no matter what flight maneuvers the aircraft adopts, it will not affect the stable supply of fuel from the fuel tank to the engine 4.

[0037] The contact surface and end surface of the oil bag 11 and the air bag 12 of the present invention adopt thickened TPU wall surface to maintain the shape, and the shrink wall surface adopts ultra-thin TPU wall surface to realize the shrinkable deformation function of the oil bag 11 and the air bag 12, and can be made into different shapes according to the cabin structure. The oil tank always keeps the entire oil tank full during the whole use process.

[0038] TPU film material, with the following parameters:

[0039] Hardness: 85±2

[0040] Specific gravity: 1.23

[0041] 300% coefficient tension (unit: kg / cm): 95 in transverse direction, 80 in longitudinal direction

[0042] Tensile strength (unit: kg / cm): 410 in transverse direction, 385 in longitudinal direction

[0043] Elongation (unit: %): 460 in transverse direction, 455 in longitudinal direction

[0044] Tear strength (unit: kg / cm): transverse 95, longitudinal 105

[0045] Yellowing resistance (unit: level): 4

[0046] Bending resistance (unit: times): 100000↑

[0047] Melting temperature (unit: ℃): 170-195

[0048] Test piece thickness (unit: mm): 0.15.

[0049] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A controllable mass center ramjet fuel system for a small large maneuverable aircraft, characterized in that: The invention comprises a pressurized vacuum fuel tank (1), a pressurized air bleed pipeline (2), a fuel supply pipeline (3) and a fixing unit. The pressurized vacuum fuel tank (1) comprises an oil bag (11) and a plurality of air bags (12). Each air bag (12) is connected to the oil bag (11) but not in communication with the oil bag. The pressurized air bleed pipeline (2) is in communication with each air bag (12), the oil bag (11) is connected to the engine (4) via the oil supply pipeline (3), and the fixing unit is used to fix the pressurized vacuum fuel tank (1) and prevent the center of gravity of the pressurized vacuum fuel tank (1) from shifting.

2. The controllable mass center ramjet fuel system for a small large maneuverable aircraft according to claim 1, characterized in that: The oil bag (11) is connected to the fuel pipeline (3) through an oil nozzle (14) and supplies fuel to the engine (4), and the air bag (12) is connected to the boost air pipeline (2) through an air nozzle (21).

3. The controllable mass center ramjet fuel system for a small large maneuverable aircraft according to claim 2, characterized in that: The interface between the oil sac (11) and the air sac (12) and the outer end surface of the air sac (12) are thickened wall surfaces (16) using a thickened TPU film of a first thickness, and the contraction surfaces of the oil sac (11) and the air sac (12) are ultra-thin wall surfaces (15) using a flexible TPU film of a second thickness, wherein the first thickness is greater than the second thickness.

4. The controllable mass center ramjet fuel system for a small large maneuverable aircraft according to claim 3, characterized in that: The oil nozzle (14) is located at the center of the contraction surface of the oil bag (11), and the air nozzle (21) is located on the thickened wall surface (16) at the outer end of the air bag (12).

5. The controllable mass center ramjet fuel system for a small large maneuverable aircraft according to claim 3 or 4, characterized in that: It also comprises a refueling pipeline (31) and a pipeline tee (32), wherein the pipeline tee (32) is arranged on the oil supply pipeline (3), and the refueling pipeline (31) is connected to the oil supply pipeline (3) through the pipeline tee (32).

6. The controllable mass center ramjet fuel system for a small large maneuverable aircraft according to claim 5, characterized in that: The fixing unit comprises a plurality of buckles (13), and the plurality of buckles (13) are located outside the center of the contraction surface of the oil bag (11) and are fixedly connected to the inner bulkhead of the aircraft.

7. The controllable mass center ramjet fuel system for a small large maneuverable aircraft according to claim 6, characterized in that: The first thickness is 1-2 mm, and the second thickness is 0.3-0.8 mm.

8. The controllable mass center ramjet fuel system for a small large maneuverable aircraft according to claim 6, characterized in that: There are two air bags (12), which are symmetrically arranged on both sides of the oil bag (11).

9. The controllable mass center ramjet fuel system for a small large maneuverable aircraft according to claim 6, characterized in that: The pressurizable vacuum fuel tank (1) completely fits into the fuel tank bulkhead and occupies the fuel tank space of the aircraft.

10. A method for using the controllable mass center ramjet fuel system for a small large maneuverable aircraft according to any one of claims 5 to 9, characterized in that: When refueling, the airbag (12) is connected to the atmosphere, and the fuel pump refuels the oil bag (11) through the refueling pipeline (31). At this time, the oil bag (11) expands to both sides, and the oil bag (11) squeezes the airbag (12) to discharge the air in the airbag (12). When the oil bag (11) is fully expanded, the airbag (12) is fully compressed, and the air is fully discharged, the fuel refueling is completed. When supplying fuel to the engine, the airbag (12) is pressurized by the ram air through the pressurized air bleed pipe (2), the oil bag (11) is squeezed by the airbag (12), the fuel pressure in the oil bag (11) increases, and the fuel is supplied to the engine (4) through the fuel supply pipe (3). At this time, the oil bag (11) contracts toward the center, and the airbag (12) continuously squeezes the oil bag (11). When the oil bag (11) is completely contracted and the airbag (12) is completely expanded, the fuel is completely exhausted.

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