A system and method for seamless mode conversion of a civil aircraft with a two-way flying wing layout

Abstract

The present invention provides a system and method for seamless mode conversion of a civil aircraft with a two-way flying wing layout. The system includes an airframe, a cabin, a rotating mechanism, and a power device; the geometric center inside the airframe rotatably mounts the cabin; the rotating mechanism is used to drive the cabin to rotate around the vertical axis of the airframe; the power device is arranged above the airframe, and the power device is fixed to the top of the cabin. Aiming at the problems that pilots and passengers bear large centrifugal overloads and the sense of direction of the pilot is interfered due to the rapid 90-degree rotation of the fuselage during the subsonic / supersonic flight mode conversion of a two-way flying wing layout supersonic civil aircraft, the present invention can ensure that the direction of the cabin remains unchanged during the aircraft mode conversion, thereby realizing seamless flight mode conversion, greatly improving the passenger comfort and reducing the control difficulty of the pilot.

Description

Technical Field

[0001] The present invention belongs to the technical field of aerospace, and particularly relates to a system and method for seamless mode conversion of a civil aircraft with a bi-directional flying wing layout. Background Art

[0002] The bi-directional flying wing layout aircraft was proposed around 2009. The aircraft has a diamond-like shape and can fly at supersonic speed. When in the low-speed mode (subsonic), the aircraft flies with a large aspect ratio shape. When accelerating to the mode conversion speed, the aircraft body rotates 90 degrees around the vertical axis and flies in the high-speed mode (supersonic) with a small aspect ratio. Due to the unique aerodynamic shape and flight mode of the bi-directional flying wing layout, it has good takeoff and landing performance at low speed (subsonic) and good low-drag and low-boom characteristics at high speed (supersonic).

[0003] Traditional supersonic civil aircraft need to be designed with a supersonic aerodynamic shape of small aspect ratio and large sweep angle to meet the requirements of supersonic cruise. This makes supersonic civil aircraft often have poor takeoff and landing performance and low-speed flight performance. This not only greatly increases the requirements for airport runways but also threatens the safety of the aircraft during takeoff and landing. The aerodynamic layout of the bi-directional flying wing that can convert between low-speed and high-speed modes just takes into account the low-speed takeoff and landing performance and the high-speed low-drag and low-boom characteristics, so it has the potential to be applied to supersonic civil aircraft.

[0004] However, if a bi-directional flying wing layout civil aircraft is designed according to the cabin layout method of traditional airliners, the following problems exist during flight mode conversion: During flight mode conversion, the aircraft body needs to rotate 90 degrees around the vertical axis located at the geometric center of the body. To minimize the influence of unsteady aerodynamic forces during the flight mode conversion process, the mode conversion of the aircraft needs to be completed in a very short time (2 - 3 seconds), which makes the rotation angular velocity of the body very large. If designed in the way that the body is fixedly connected to the cabin in traditional airliners, passengers far from the rotation center in the cabin will bear a large centrifugal overload due to the large rotation radius, which greatly reduces the comfort of passengers during the flight. In addition, since the body rotates 90 degrees during mode conversion, the pilot will change from facing the flight direction to facing the side of the flight direction, which changes the sense of direction for the pilot, interferes with the pilot's control awareness, increases the control difficulty, and affects flight safety.

[0005] Therefore, it is necessary to solve the above problems existing in the flight mode conversion process of bi-directional flying wing layout civil aircraft. Summary of the Invention

[0006] Aiming at the defects existing in the prior art, the present invention provides a system and method for seamless mode conversion of a bi-directional flying wing layout civil aircraft, which can effectively solve the above problems.

[0007] The technical solution adopted by the present invention is as follows:

[0008] The present invention provides a seamless modal conversion system for a civil aircraft with a two-way flying wing layout, including: a fuselage (1), a cabin (2), a rotating mechanism (3) and a power device (4);

[0009] The geometric center inside the fuselage (1) rotatably mounts the cabin (2); the rotating mechanism (3) is used to drive the cabin (2) to rotate around the vertical axis of the fuselage (1); the power device (4) is arranged above the fuselage (1), and the power device (4) is fixed to the top of the cabin (2).

[0010] Preferably, the fuselage (1) is a flat two-way flying wing layout structure with a large aspect ratio flying wing in the low-speed modal flight direction and a small aspect ratio flying wing in the high-speed modal flight direction;

[0011] The fuselage (1) includes a fuselage longitudinal beam (101), a low-speed wing rib (102) and a high-speed wing rib (103); the low-speed wing rib (102) is a subsonic airfoil, arranged in parallel in the low-speed modal flight direction, and connected by the fuselage longitudinal beam (101) to form an integral body; the high-speed wing rib (103) is a supersonic airfoil, arranged in parallel in the high-speed modal flight direction, and distributed on both sides of the fuselage longitudinal beam (101), and cross-arranged and orthogonally fixed with several of the low-speed wing ribs (102) in the middle area.

[0012] Preferably, the cabin (2) is a flat-round hemispherical closed structure, including a cabin lower wall plate (208) and a cabin upper wall plate (211); the cabin lower wall plate (208) and the cabin upper wall plate (211) enclose a flat-round hemispherical closed sphere;

[0013] The fuselage (1) further includes an X-shaped support (104), a disc-shaped rotating shaft (105) and a fuselage frame (106); the number of the fuselage frames (106) is two, sleeved outside the cabin (2), and fixed to the inner wall of the fuselage (1); the X-shaped support (104) is fixedly installed between the bottoms of the two fuselage frames (106); the top surface of the disc-shaped rotating shaft (105) is fixed to the cabin lower wall plate (208), and the top surface of the disc-shaped rotating shaft (105) is rotatably installed inside the X-shaped support (104). Therefore, the cabin (2) can rotate relative to the fuselage (1) through the disc-shaped rotating shaft (105).

[0014] Preferably, the cabin (2) further includes an emergency escape exit (201), an inner cabin partition (202), a galley bar (203), a cockpit seat (204), a cabin seat (205), a cabin door (206), a partition door (207), a crew rest sofa (209), and a toilet (210);

[0015] The cockpit seat (204) is located in the cockpit at the front end inside the cabin (2); the cabin seat (205) is located in the center of the cabin (2); the toilet (210) is located at the rear of the cabin (2); both sides of the cabin (2) are crew rest areas, where the crew rest sofa (209) is provided and separated from the passenger area by the inner cabin partitions (202) on both sides; two partition doors (207) are provided on each inner cabin partition (202); the cabin door (206) is located at the left rear of the cockpit. When the cabin door (206) is opened, passengers enter and exit the aircraft through the escalator; four emergency escape exits (201) are provided around the cabin (2), and the emergency escape exits (201) are communicated with four openings at the outer skin.

[0016] Preferably, the cockpit in the cabin (2) adopts a vision enhancement system, that is, cameras and sensors are installed on various parts of the outer surface of the aircraft, and liquid crystal displays are arranged inside the cockpit. The on-board computer enhances the image information of the outside of the aircraft captured by the cameras and sensors and projects it onto the liquid crystal display in front of the pilot to improve the pilot's situational awareness of the environment around the aircraft.

[0017] Preferably, the number of the rotating mechanisms (3) is two, and they are symmetrically installed on both sides of the cabin (2);

[0018] Each rotating mechanism (3) includes a motor (301), a gear (302), a reducer housing (303), and a rack (304); the rack (304) is fixedly installed along the arc edge of the cabin (2); the reducer housing (303) is connected between the two fuselage frames (106), and a motor (301) and a reduction mechanism are arranged inside the reducer housing (303); the gear (302) is arranged at the center of the upper part of the reducer housing (303), and the gear (302) meshes with the rack (304); the output end of the motor (301) is connected to the gear (302) through the reduction mechanism to drive the gear (302) to rotate, thereby driving the rack (304) to rotate, and finally driving the cabin (2) to rotate.

[0019] Preferably, each of the rotation mechanisms (3) further includes a support wheel (305); the support wheel (305) is installed on the surface of the reducer housing (303), and the support wheel (305) contacts the lower surface of the passenger cabin (2) to support the passenger cabin (2) and increase the stability of the passenger cabin (2) during rotation.

[0020] Preferably, the power device (4) includes an engine (401) and an engine support (402); the top of the engine support (402) is fixedly connected to the engine (401); the bottom of the engine support (402) passes through the central bearing installed in the airframe (1) and is then fixedly connected to the passenger cabin (2); wherein, the outer ring of the central bearing is fixed to the airframe (1), and the inner ring of the central bearing is fixed to the engine support (402) so that the engine (401) can rotate relative to the airframe (1).

[0021] The present invention also provides a conversion method for a seamless mode conversion system based on a bi-directional flying wing layout civil aircraft, including the following steps:

[0022] The airframe (1) flies along the oncoming flow direction with a high aspect ratio wing in the low-speed mode and flies along the oncoming flow direction with a low aspect ratio wing in the high-speed mode; when converting from the low-speed mode to the high-speed mode, the airframe (1) rotates 90 degrees relative to the oncoming flow direction, while the directions of the engine (401) and the passenger cabin (2) remain unchanged and always point to the flight direction.

[0023] Preferably, it includes:

[0024] The airframe (1) is provided with drag rudders in both the low-speed mode and the high-speed mode. When mode conversion is required, the drag rudders on the airframe (1) are asymmetrically opened to generate a yaw moment, so that the airframe (1) rotates around the vertical axis;

[0025] During the rotation of the airframe (1) around the vertical axis, since the passenger cabin (2) and the engine (401) are fixed, by using the conservation of angular momentum characteristics of the internal rotor of the engine (401), the directions of the passenger cabin (2) and the engine (401) are kept basically pointing to the flight direction, and then the rotation mechanism (3) is started for auxiliary fine-tuning, that is: the rotation mechanism (3) drives the whole of the passenger cabin (2) and the engine (401) to rotate in the opposite direction relative to the airframe (1), so as to accurately ensure that the directions of the passenger cabin (2) and the engine (401) always remain unchanged and point to the flight direction during mode conversion; after the airframe (1) completes a 90-degree rotation, the locking mechanism of the rotation mechanism (3) is locked to prevent relative rotation between the passenger cabin (2) and the airframe (1).

[0026] The non-perceptible mode conversion system and method for a civil aircraft with a bidirectional flying wing layout provided by the present invention have the following advantages:

[0027] Aiming at the problems that during the subsonic / supersonic flight mode conversion of a civil aircraft with a bidirectional flying wing layout, the pilot and passengers bear a large centrifugal overload due to the rapid 90-degree rotation of the fuselage and the driving direction sense of the pilot is interfered, the present invention can ensure that the direction of the cabin remains unchanged during the aircraft mode conversion, so as to achieve non-perceptible flight mode conversion, greatly improving the passenger comfort and reducing the control difficulty of the pilot. Brief Description of the Drawings

[0028] Figure 1 It is a schematic diagram of the supersonic mode structure of the civil aircraft with a bidirectional flying wing layout provided by the present invention;

[0029] Figure 2 It is a schematic diagram of the transition mode structure of the civil aircraft with a bidirectional flying wing layout provided by the present invention;

[0030] Figure 3 It is a schematic diagram of the subsonic mode structure of the civil aircraft with a bidirectional flying wing layout provided by the present invention;

[0031] Figure 4 It is a front view of the civil aircraft with a bidirectional flying wing layout provided by the present invention;

[0032] Figure 5 It is a top view of the civil aircraft with a bidirectional flying wing layout provided by the present invention;

[0033] Figure 6 It is a schematic diagram of the structure of the cabin provided by the present invention;

[0034] Figure 7 It is a top view of the cabin provided by the present invention;

[0035] Figure 8 It is a bottom view of the cabin provided by the present invention;

[0036] Figure 9 It is a partial enlarged view of the rotating mechanism provided by the present invention;

[0037] Figure 10 It is a partial enlarged view of the engine and the cabin provided by the present invention.

[0038] Wherein:

[0039] Airframe 1, fuselage longitudinal beam 101, low-speed wing rib 102, high-speed wing rib 103, X-shaped support 104, disk-shaped rotating shaft 105, fuselage frame 106;

[0040] Cabin 2, emergency escape exit 201, cabin inner partition 202, galley bar 203, cockpit seat 204, cabin seat 205, cabin door 206, partition door 207, lower cabin wall panel 208, crew rest sofa 209, toilet 210, upper cabin wall panel 211;

[0041] Rotating mechanism 3, motor 301, gear 302, reducer housing 303, rack 304, support wheel 305;

[0042] Power device 4, engine 401, engine mount 402. Detailed implementation

[0043] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention clearer, the present invention will be further described in detail below with reference to 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 used to limit the present invention.

[0044] The present invention provides a system and method for seamless modal conversion of a civil aircraft with a bi-directional flying wing layout, which can effectively solve problems such as large centrifugal overload on passengers and interference with the pilot's operating awareness during modal conversion.

[0045] Please refer to Figures 1 - 10 , the present invention provides a seamless modal conversion system for a civil aircraft with a bi-directional flying wing layout, including: fuselage 1, cabin 2, rotating mechanism 3 and power device 4; the geometric center inside the fuselage 1 rotatably mounts the cabin 2; the rotating mechanism 3 is used to drive the cabin 2 to rotate around the vertical axis of the fuselage 1; the power device 4 is arranged above the fuselage 1, and the power device 4 is fixed to the top of the cabin 2.

[0046] The following will introduce the fuselage 1, cabin 2, rotating mechanism 3 and power device 4 in detail respectively:

[0047] (1) Fuselage 1

[0048] The fuselage 1 is a flat bi-directional flying wing layout structure with a large aspect ratio flying wing in the low-speed modal flight direction and a small aspect ratio flying wing in the high-speed modal flight direction; as a specific embodiment, in the present invention, the low-speed mode can be a subsonic mode; the high-speed mode can be a supersonic mode.

[0049] The airframe 1 includes a fuselage longitudinal beam 101, a low-speed wing rib 102, and a high-speed wing rib 103; the low-speed wing rib 102 is of a subsonic airfoil, arranged in parallel in the flight direction of the low-speed mode, and connected by the fuselage longitudinal beam 101 to form an integral body; the high-speed wing rib 103 is of a supersonic airfoil, arranged in parallel in the flight direction of the high-speed mode, and distributed on both sides of the fuselage longitudinal beam 101, and intersects and orthogonally fixes with several low-speed wing ribs 102 in the middle region. Therefore, in the present invention, the high-speed wing rib 103 and the low-speed wing rib 102 are arranged in a cross pattern and orthogonally fixed before and after the middle of the airframe 1.

[0050] (2) The passenger cabin 2

[0051] The passenger cabin 2 is a flat and round hemispherical closed structure, located at the geometric center of the airframe 1, and includes a passenger cabin lower wall panel 208 and a passenger cabin upper wall panel 211; the passenger cabin lower wall panel 208 and the passenger cabin upper wall panel 211 enclose a flat and round hemispherical closed sphere;

[0052] The airframe 1 further includes an X-shaped support 104, a disc-shaped rotating shaft 105, and a fuselage frame 106; the number of the fuselage frames 106 is two, sleeved outside the passenger cabin 2 and fixed to the inner wall of the airframe 1; the X-shaped support 104 is fixedly installed between the bottoms of the two fuselage frames 106; the top surface of the disc-shaped rotating shaft 105 is fixed to the passenger cabin lower wall panel 208, and the top surface of the disc-shaped rotating shaft 105 is rotatably installed inside the X-shaped support 104. Therefore, the passenger cabin 2 can rotate relative to the airframe 1 through the disc-shaped rotating shaft 105. For example, the passenger cabin lower wall panel 209 is fixedly connected to the upper surface of the disc-shaped rotating shaft 105 and contacts the support wheel 305 located on the reducer housing 303, and the passenger cabin 2 can rotate 90 degrees around the disc-shaped rotating shaft 105; the passenger cabin upper wall panel 211 is used for fixedly connecting to the bottom of the engine support 402. There is a rack 304 at the edge of the passenger cabin lower wall panel 209, distributed at the one-quarter arc length of the center symmetry of the passenger cabin lower wall panel 209, and the rack 304 meshes with the gear 302 on the reducer housing 303.

[0053] The cabin 2 also includes an emergency escape exit 201, an internal partition 202 in the cabin, a kitchen bar 203, cockpit seats 204, cabin seats 205, a cabin door 206, a partition door 207, a crew rest sofa 209 and a toilet 210; the cockpit seats 204 are located in the cockpit at the front end inside the cabin 2, and the number of the cockpit seats 204 is two; the cabin seats 205 are located in the center of the cabin 2; the toilet 210 is located at the rear of the cabin 2; both sides of the cabin 2 are crew rest areas, where crew rest sofas 209 are provided and separated from the passenger area by the internal partitions 202 on both sides; there are two partition doors 207 on each internal partition 202 in the cabin; the cabin door 206 is located at the left rear of the cockpit, and when the cabin door 206 is opened, passengers enter and exit the aircraft through the escalator under the fuselage; there are four emergency escape exits 201 arranged around the cabin 2, and the emergency escape exits 201 are communicated with four openings at the outer skin.

[0054] The cockpit in the cabin 2 adopts a vision enhancement system, that is, cameras and sensors are installed on various parts of the outer surface of the aircraft, and liquid crystal displays are arranged inside the cockpit. The airborne computer enhances the image information outside the aircraft captured by the cameras and sensors and projects it onto the liquid crystal display in front of the pilot, which can greatly improve the pilot's situational awareness of the environment around the aircraft.

[0055] (Three) Rotating mechanism 3

[0056] The number of the rotating mechanisms 3 is two, symmetrically installed on both sides of the cabin 2, and specifically can be installed at the front and rear between two fuselage frames 106 in the middle of the fuselage; each rotating mechanism 3 includes a motor 301, a gear 302, a reducer housing 303 and a rack 304; the rotating mechanism 3 is a mechanical mechanism located at the front and rear of the cabin 2, driven by the motor 301 to drive the reducer and then drive the gear 302 to rotate; the rack 304 is fixedly installed along the arc edge of the cabin 2; the reducer housing 303 is connected between two fuselage frames 106, and a motor 301 and a reduction mechanism are arranged inside the reducer housing 303; a gear 302 is arranged at the center of the upper part of the reducer housing 303, and the gear 302 meshes with the rack 304 at the edge of the cabin; the output end of the motor 301 is connected to the gear 302 through the reduction mechanism, used to drive the gear 302 to rotate, and then drive the rack 304 to rotate, and finally drive the cabin 2 to rotate.

[0057] Each rotating mechanism 3 also includes a support wheel 305; the support wheel 305 is installed on the surface of the reducer housing 303, and the support wheel 305 contacts the lower surface of the cabin 2, used to support the cabin 2 and increase the stability when the cabin 2 rotates.

[0058] (Four) Power device 4

[0059] The power plant 4 includes an engine 401 and an engine mount 402; the engine mount 402 can adopt a T-shaped engine mount. The top of the engine mount 402 is fixedly connected to the engine 401; the bottom of the engine mount 402 passes through the central bearing installed on the fuselage 1 and is then fixedly connected to the passenger cabin 2; wherein, the outer ring of the central bearing is fixed to the fuselage 1, and the inner ring of the central bearing is fixed to the engine mount 402, so that the engine 401 can rotate relative to the fuselage 1.

[0060] As an embodiment, the engine 401 is connected to the fuselage 1 through the engine mount 402. The engine mount 402 can rotate 90 degrees relative to the fuselage 1. The engine mount 402 is fixed downward to the passenger cabin 2 to ensure that the direction of the engine 401 is consistent with the facing direction of the pilot and passengers in the passenger cabin. The engine 401 adopts two variable cycle engines located in the upper center of the fuselage 1, with oblique cut intake ducts and serrated tail nozzles.

[0061] The present invention also provides a conversion method for a seamless mode conversion system based on a civil aircraft with a bidirectional flying wing layout, including the following steps:

[0062] When the fuselage 1 is in the low-speed mode, it flies along the oncoming flow direction with a high aspect ratio wing, and when in the high-speed mode, it flies along the oncoming flow direction with a low aspect ratio wing; when converting from the low-speed mode to the high-speed mode, the fuselage 1 rotates 90 degrees relative to the oncoming flow direction, while the directions of the engine 401 and the passenger cabin 2 remain unchanged and always point to the flight direction.

[0063] Specifically, the fuselage 1 is provided with drag rudders in both the low-speed mode and the high-speed mode. When mode conversion is required, the drag rudders on the fuselage 1 are asymmetrically opened to generate a yaw moment, so that the fuselage 1 rotates around the vertical axis.

[0064] During the rotation of the fuselage 1 around the vertical axis, since the passenger cabin 2 and the engine 401 are fixed, by utilizing the conservation of angular momentum of the internal rotor of the engine 401, the directions of the passenger cabin 2 and the engine 401 are kept basically pointing to the flight direction. Then, the rotation mechanism 3 is started for auxiliary fine-tuning, that is: the rotation mechanism 3 drives the whole of the passenger cabin 2 and the engine 401 to rotate in the opposite direction relative to the fuselage 1, so as to accurately ensure that the directions of the passenger cabin 2 and the engine 401 always remain unchanged and point to the flight direction during mode conversion; after the fuselage 1 completes a 90-degree rotation, the locking mechanism of the rotation mechanism 3 is locked to prevent relative rotation between the passenger cabin 2 and the fuselage 1.

[0065] The following introduces a specific embodiment:

[0066] Figures 1 - 5In it, the airframe 1 is a high aspect ratio and small sweep angle flying wing in the subsonic direction, ensuring that the aircraft has a high lift-drag ratio at subsonic speeds. In the supersonic direction, it is a small aspect ratio and large sweep angle flying wing, ensuring good low drag and low sonic boom characteristics at supersonic speeds. The interior of the airframe includes high-speed wing ribs 103, low-speed wing ribs 102, and fuselage stringers 101. The high-speed wing ribs 103 are of supersonic airfoil type, which can achieve small shock wave resistance during supersonic cruise; the low-speed wing ribs 102 are of subsonic airfoil type and are arranged in parallel in the low-speed flight mode direction; the high-speed wing ribs 103 and the low-speed wing ribs 102 are orthogonally fixed before and after in the middle of the fuselage and form a box structure with the external skin, which can increase the stiffness and stability of the structure. The low-speed wing ribs 102 are connected by the fuselage stringers 101. Since the overall aircraft has a wing-body blended flying wing layout, lift can be generated at each part along the span of the subsonic wing, which is beneficial to reducing the wing root bending moment. At the same time, the two-way flying wing has a larger thickness at the symmetry plane, which can bring a larger moment of inertia and increase the bending stiffness coefficient of the structure from the perspective of structural mechanics, reduce stress concentration, and reduce the structural weight. The airframe 1 is provided with drag rudders in both the low-speed mode and the high-speed mode. When mode conversion is required, the drag rudders on the airframe 1 are asymmetrically opened to generate a yaw moment, so that the airframe 1 rotates around the central vertical axis.

[0067] Figures 6 - 8In it, the passenger cabin 2 is a flat and round hemispherical closed structure, located at the geometric center of the airframe 1, and is connected to the fuselage frame 106 through a disc-shaped rotating shaft 105 at the lower wall panel 208 of the passenger cabin. The upper wall panel 211 of the passenger cabin is fixed to the bottom of the "T"-shaped engine support 402; the passenger cabin 2 includes an emergency escape exit 201, an internal partition 202 of the passenger cabin, a kitchen bar 203, a cockpit seat 204, a passenger seat 205, a passenger cabin door 206, a partition door 207, a lower wall panel 208 of the passenger cabin, a crew rest sofa 209, a toilet 210, and an upper wall panel 211 of the passenger cabin. The overall passenger cabin 2 is flat and round hemispherical, located at the geometric center of the airframe 1, where the lower wall panel 208 of the passenger cabin is fixedly connected to the upper surface of the disc-shaped rotating shaft 105 and contacts the support wheel 305 located on the reducer housing 303, enabling the passenger cabin to rotate 90 degrees around the disc-shaped rotating shaft 105. The rotating shaft at the bottom of the lower wall panel 208 of the passenger cabin is designed as a disc shape to increase the contact area, reduce stress concentration, and at the same time, two support wheels 305 located on the reducer housing 303 contact the lower surface of the passenger cabin to increase the stability of the passenger cabin. The disc-shaped rotating shaft 105 is provided with an X-shaped support 104 at its bottom, and the X-shaped support 104 is fixed to the fuselage frame 106; inside the passenger cabin 2, it is necessary to make full use of the disc-shaped passenger cabin space and ensure sufficient activity space for the driver and passengers. Two cockpit seats 204 are located in the cockpit at the front end inside the passenger cabin to ensure separation between the driver and passengers. The passenger seats 205 are located in the center of the passenger cabin, designed in a total of 5 rows, with 4 seats in each row, separated by a corridor in the middle. The toilet 210 is located at the rear of the passenger cabin, and both sides of the passenger cabin are crew rest areas, equipped with crew rest sofas 209, separated from the passenger area by the internal partitions 202 on both sides. Two partition doors 207 are provided on each internal partition 202 of the passenger cabin to ensure the entry and exit of passengers and the crew; the passenger cabin door 206 is located on the lower wall panel 208 of the passenger cabin at the left rear of the cockpit. When the passenger cabin door 206 is opened, passengers enter and exit the aircraft through the escalator under the fuselage. At the same time, four emergency escape exits 201 are provided around the upper wall panel 211 of the passenger cabin, and the emergency escape exits 201 are connected to four openings at the outer skin, ensuring that passengers can escape through the four emergency escape exits 201 in the shortest time regardless of whether the aircraft is in a low-speed mode or a high-speed mode. There are racks 304 at the edge of the lower wall panel 208 of the passenger cabin, distributed at the quarter arc positions that are centrally symmetric on the circular lower wall panel. Distributing the racks 304 at the edge of the lower wall panel 208 of the passenger cabin can maximize the force arm generated by the gear on the passenger cabin, so that the motor 301 does not need to generate a large torque to drive the rotation of the passenger cabin 2, reducing the load on the motor 301.

[0068] Figures 6 - 8In [description], the cockpit in the passenger cabin 2 adopts a vision enhancement system. That is, cameras and sensors are installed on various parts of the outer surface of the aircraft, and liquid crystal displays are arranged inside the cockpit. The airborne computer enhances the image information of the outside of the aircraft captured by the cameras and sensors and projects it onto the liquid crystal display in front of the pilot, which can greatly improve the pilot's situational awareness of the aircraft's surrounding environment, thus facilitating the pilot's operation of the aircraft and improving flight safety.

[0069] Figure 9 and Figure 10 In [description], the rotating mechanism 3 is arranged on the fuselage frames 106 on both sides of the passenger cabin outside. The motor 301 drives the reducer and drives the gear 302 to rotate. The gear 302 meshes with the rack 304 on the edge of the fixed-wing circular passenger cabin to drive the passenger cabin 2 to rotate; the rotating mechanism includes a motor 301, a gear 302, a reducer housing 303, and a rack 304; the reducer housing 303 is connected to the bottom of the two fuselage frames 106. The inside of the reducer housing 303 contains a motor 301 and a reduction mechanism. There is a gear 302 in the center of the upper part of the reducer housing 303, which meshes with the rack 304 on the edge of the passenger cabin to drive the passenger cabin 2 to rotate. When the aircraft performs a mode conversion, the fuselage 1 rotates 90 degrees around the vertical axis. At the same time, the motor 301 inside the rotating mechanism starts to operate, driving the passenger cabin 2 to rotate in the opposite direction relative to the fuselage, ensuring that the directions of the passenger cabin 2 and the engine 401 always remain unchanged and point to the flight direction during the mode conversion. After the fuselage 1 completes a 90-degree rotation, the locking mechanism in the reducer housing 303 is locked to prevent relative rotation between the passenger cabin 2 and the fuselage 1. By the above method, the problem that passengers in a civil aircraft with a bidirectional flying wing layout have to bear a large centrifugal overload during mode conversion, which affects the riding comfort, is solved. On the other hand, it also solves the problem that the pilot's sense of direction is confused due to the pilot changing from facing the flight direction to facing the side of the flight direction when the fuselage rotates 90 degrees, which affects the operation safety, thereby improving the riding comfort of passengers and the operation safety of pilots. Among them, there are two sets of reduction mechanisms, which are respectively located in the front and rear between the two fuselage frames in the middle of the fuselage. Both sets of rotating mechanisms can work independently to complete the rotation of the passenger cabin relative to the fuselage during mode conversion. When one system fails, the other can continue to work to meet the redundancy design requirements in airworthiness regulations, thus enhancing the safety during mode conversion. In addition, the motor of the rotating mechanism can work independently. When the aircraft is being repaired on the ground, it can also control the rotation of the passenger cabin and the engine relative to the fuselage, facilitating fault detection and parts replacement on the ground.

[0070] Table 1 compares the centrifugal overload at different radii from the axis of rotation during the mode conversion between the traditional cabin layout (the cabin is fixed to the fuselage) and the cabin layout with a rotating mechanism. The mode conversion time is 2 seconds. It can be clearly seen from Table 1 that compared with the cabin layout of traditional biplane-wing civil aircraft, the present invention can greatly reduce the centrifugal overload during mode conversion, reduce the discomfort of passengers, and improve the riding comfort.

[0071] Table 1 Centrifugal Overload during Mode Conversion of Different Cabin Layouts

[0072]

[0073] Figure 10 In it, the power plant 4 is two variable-cycle engines 401 with oblique-cut intake ducts and serrated tail nozzles located at the upper part of the center of the fuselage, fixed on the "T"-shaped engine support 402. The "T"-shaped engine support 402 is fixed on the central bearing of the upper fuselage frame, enabling it to rotate 90 degrees relative to the fuselage 1. And the engine support 402 is fixed to the cabin 2 downward to ensure that the direction of the engine 401 is consistent with the faces of the pilots and passengers in the cabin. The main rotation torque during the rotation of the fuselage is provided by the asymmetric cracking of the drag rudder. The advantage of fixing the cabin to the engine support is that the cabin can maintain its direction basically unchanged by using the conservation of angular momentum of the internal rotor of the engine. The gear-rack meshing mechanism of the rotating mechanism mainly plays an auxiliary role in fine-tuning and locking, which makes the rotation torque required by the rotating mechanism very small, and the contact stress between the gear and the rack is very small, thus reducing the load on the motor and further reducing the structural weight of the rotating mechanism.

[0074] The non-perceptible mode conversion system and method for a biplane-wing civil aircraft provided by the present invention have the following advantages:

[0075] (1) When the aircraft performs mode conversion, the fuselage rotates 90 degrees around the vertical axis. At the same time, the motors inside the rotating mechanisms on both sides of the cabin start to operate, driving the cabin to rotate in the opposite direction relative to the fuselage through the gear-rack meshing, ensuring that the directions of the cabin and the engine remain unchanged during mode conversion and pointing to the flight direction. After the fuselage rotates 90 degrees, the locking mechanism in the reducer housing is locked to prevent the relative rotation of the cabin and the fuselage. By the above method, the problem that passengers of biplane-wing civil aircraft suffer from large centrifugal overload during mode conversion, which affects the riding comfort, is solved. On the other hand, the problem that the sense of direction is confused due to the pilot changing from facing the flight direction to facing the side of the flight direction when the fuselage rotates 90 degrees, which affects the operation safety, is also solved, thereby improving the riding comfort of passengers and the operation safety of pilots.

[0076] (2) The two engines are fixed to the cabin through engine mounts passing through the fuselage bulkhead. The main rotational torque during the rotation of the airframe is provided by the asymmetric cracking of the drag rudder. The advantage of fixing the cabin to the engine mounts is that the cabin can maintain a basically constant direction by utilizing the conservation of angular momentum of the internal rotor of the engine. The rack and pinion meshing mechanism of the rotating mechanism mainly plays the role of assisting in fine adjustment and locking, which enables the rotating mechanism to require a very small rotational torque and the contact stress between the rack and pinion to be very small, thereby reducing the load on the motor and further reducing the structural weight of the rotating mechanism.

[0077] (3) Design a dual set of rotating mechanisms. The two sets of rotating mechanisms can work independently. When one set of rotating mechanisms fails, the other set can continue to work, meeting the redundancy design requirements in airworthiness regulations, thus enhancing the safety during the mode conversion process.

[0078] (4) The motors of the rotating mechanism can work independently. When the aircraft is under maintenance on the ground, the cabin and the engine can also be controlled to rotate relative to the airframe, facilitating the troubleshooting and component replacement of the aircraft on the ground.

[0079] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as within the protection scope of the present invention.

Claims

1. A seamless modal conversion system for a civil aircraft with a two-way flying wing layout, characterized in that Comprising: An airframe (1), a cabin (2), a rotating mechanism (3) and a power plant (4); The geometric center inside the airframe (1) rotatably mounts the cabin (2); the rotating mechanism (3) is used to drive the cabin (2) to rotate around the vertical axis of the airframe (1); the power plant (4) is arranged above the airframe (1), and the power plant (4) is fixed to the top of the cabin (2); The cabin (2) is a flat semi-spherical closed structure, including a cabin lower wall panel (208) and a cabin upper wall panel (211); the cabin lower wall panel (208) and the cabin upper wall panel (211) enclose a flat semi-spherical closed sphere; The airframe (1) further includes an X-shaped support (104), a disc-shaped rotating shaft (105) and a fuselage frame (106); the number of the fuselage frames (106) is two, sleeved outside the cabin (2) and fixed to the inner wall of the airframe (1); the X-shaped support (104) is fixedly installed between the bottoms of the two fuselage frames (106); the top surface of the disc-shaped rotating shaft (105) is fixed to the cabin lower wall panel (208), and the top surface of the disc-shaped rotating shaft (105) is rotatably installed inside the X-shaped support (104). Therefore, the cabin (2) can rotate relative to the airframe (1) through the disc-shaped rotating shaft (105).

2. The seamless mode conversion system of a civil aircraft with a bidirectional flying wing layout according to claim 1, characterized in that The airframe (1) is a flat two-way flying wing layout structure with a large aspect ratio flying wing in the low-speed flight mode and a small aspect ratio flying wing in the high-speed flight mode; The airframe (1) includes a fuselage longitudinal beam (101), a low-speed wing rib (102) and a high-speed wing rib (103); the low-speed wing rib (102) is a subsonic airfoil, arranged in parallel in the low-speed flight mode and connected into a whole through the fuselage longitudinal beam (101); the high-speed wing rib (103) is a supersonic airfoil, arranged in parallel in the high-speed flight mode, distributed on both sides of the fuselage longitudinal beam (101), and cross-arranged and orthogonally fixed with several of the low-speed wing ribs (102) located in the middle area.

3. The seamless mode conversion system for a civil aircraft with a bidirectional flying wing layout according to claim 1, characterized in that The cabin (2) further includes an emergency escape exit (201), an inner cabin partition (202), a kitchen bar (203), a cockpit seat (204), a cabin seat (205), a cabin door (206), a partition door (207), a crew rest sofa (209) and a toilet (210); The cockpit seat (204) is located in the cockpit at the front end inside the cabin (2); the cabin seats (205) are located in the center of the cabin (2); the toilet (210) is located at the rear of the cabin (2); on both sides of the cabin (2) are crew rest areas, provided with crew rest sofas (209), separated from the passenger area by the cabin inner partitions (202) on both sides; each of the cabin inner partitions (202) is provided with two partition doors (207); the cabin door (206) is located at the left rear of the cockpit. When the cabin door (206) is opened, passengers enter and exit the aircraft through the escalator; four emergency escape exits (201) are provided around the cabin (2), and the emergency escape exits (201) are communicated with four openings at the outer skin.

4. The seamless mode conversion system for a civil aircraft with a bidirectional flying wing layout according to claim 1, characterized in that, The cockpit in the cabin (2) adopts a vision enhancement system, that is, cameras and sensors are installed on various parts of the outer surface of the aircraft, and liquid crystal displays are arranged inside the cockpit. The airborne computer enhances the image information of the outside of the aircraft captured by the cameras and sensors and projects it onto the liquid crystal display in front of the pilot to improve the pilot's situational awareness of the environment around the aircraft.

5. The non-perceptible mode conversion system of a civil aircraft with a two-way flying wing layout according to claim 1, characterized in that, The number of the rotating mechanisms (3) is two, symmetrically installed on both sides of the cabin (2); Each of the rotating mechanisms (3) includes a motor (301), a gear (302), a reducer housing (303) and a rack (304); the rack (304) is fixedly installed along the arc edge of the cabin (2); the reducer housing (303) is connected between the two fuselage frames (106), and a motor (301) and a reduction mechanism are arranged inside the reducer housing (303); the gear (302) is arranged at the center of the upper part of the reducer housing (303), and the gear (302) meshes with the rack (304); the output end of the motor (301) is connected to the gear (302) through the reduction mechanism, used to drive the gear (302) to rotate, and then drive the rack (304) to rotate, and finally drive the cabin (2) to rotate.

6. The imperceptible mode conversion system of a civil aircraft with a two-way flying wing layout according to claim 5, characterized in that, Each of the rotating mechanisms (3) further includes a support wheel (305); the support wheel (305) is installed on the surface of the reducer housing (303), and the support wheel (305) contacts the lower surface of the cabin (2), used to support the cabin (2) and increase the stability of the cabin (2) during rotation.

7. The non-perceptible mode conversion system of a civil aircraft with a two-way flying wing layout according to claim 1, characterized in that The power device (4) includes an engine (401) and an engine support (402); the top of the engine support (402) is fixedly connected to the engine (401); the bottom of the engine support (402) passes through the central bearing installed on the fuselage (1) and is fixedly connected to the cabin (2); wherein, the outer ring of the central bearing is fixed to the fuselage (1), and the inner ring of the central bearing is fixed to the engine support (402) so that the engine (401) can rotate relative to the fuselage (1).

8. A conversion method for a seamless modal conversion system of a civil aircraft with a two-way flying wing layout according to any one of claims 1-7, characterized in that, Including the following steps: The airframe (1) flies along the oncoming flow direction with a wing of high aspect ratio in the low-speed mode, and flies along the oncoming flow direction with a wing of low aspect ratio in the high-speed mode; when converting from the low-speed mode to the high-speed mode, the airframe (1) rotates 90 degrees relative to the oncoming flow direction, while the directions of the engine (401) and the passenger cabin (2) remain unchanged and always point to the flight direction.

9. The conversion method of a seamless modal conversion system for a civil aircraft based on a two-way flying wing layout according to claim 8, characterized in that, It includes: The airframe (1) is provided with drag rudders in both the low-speed mode and the high-speed mode. When mode conversion is required, the drag rudders on the airframe (1) are asymmetrically opened to generate a yaw moment, so that the airframe (1) rotates around the vertical axis; During the rotation of the airframe (1) around the vertical axis, since the passenger cabin (2) and the engine (401) are fixed, by utilizing the conservation of angular momentum of the internal rotor of the engine (401), the directions of the passenger cabin (2) and the engine (401) are kept basically pointing to the flight direction. Then, the rotation mechanism (3) is started for auxiliary fine adjustment, that is: the rotation mechanism (3) drives the whole of the passenger cabin (2) and the engine (401) to rotate in the opposite direction relative to the airframe (1), thereby accurately ensuring that the directions of the passenger cabin (2) and the engine (401) always remain unchanged and point to the flight direction during mode conversion; after the airframe (1) completes a 90-degree rotation, the locking mechanism of the rotation mechanism (3) is locked to prevent relative rotation between the passenger cabin (2) and the airframe (1).

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