CN115571327B - Distributed electric propulsion ultra-short take-off and landing fixed-wing aircraft platform - Google Patents

Abstract

The application discloses distributing type electric propulsion ultrashort distance take-off and landing fixed wing aircraft platform includes: a fuselage, a left wing, a right wing; the left wing and the right wing are both provided with a plurality of inner high-lift propellers and a plurality of outer high-lift propellers from inside to outside in sequence, the ratio of the diameter of the inner high-lift propellers to the average aerodynamic chord length of the wings is 0.6-0.8, and the ratio of the diameter of the outer high-lift propellers to the average aerodynamic chord length of the wings is 0.4-0.6; the distance between the rotating axes of the outer high-lift propeller and the inner high-lift propeller and the plane of the wing chord line is 0.3 to 0.5 times of the diameter of the corresponding propeller, and the distance between the rotating planes of the outer high-lift propeller and the inner high-lift propeller and the front and back of the wing leading edge is 0.3 to 0.5 times of the diameter of the corresponding propeller. The problem that an aircraft in the related art is limited by a pneumatic structure and is difficult to achieve short-distance take-off and landing while high flight performance is kept is solved.

Description

Distributed electric propulsion ultra-short take-off and landing fixed-wing aircraft platform

Technical Field

The application relates to the technical field of aviation aircrafts, in particular to a distributed electric propulsion ultra-short take-off and landing fixed-wing aircraft platform.

Background

Electric aircraft are one of the development directions of aviation aircraft. Compared with traditional fossil fuel power, the electrokinetic technology has many unique advantages: simple structure, high reliability, small vibration, no oil pipeline, more flexible arrangement, scale independence and the like. In particular, the size independence is that a single high-power electric propulsion unit is replaced by a plurality of low-power electric propulsion units, and the power-to-weight ratio and the efficiency of the whole propulsion system are basically kept unchanged under the condition that the total power is kept the same. Therefore, the electric airplane can adopt a distributed electric propulsion power device to fully couple a power system with the overall aerodynamic design of the airplane, and some new use functions or flight performance improvement are generated.

The improvement in takeoff and landing performance of aircraft has been the direction of efforts by aircraft manufacturers. It is generally desirable that the shorter the take-off and landing distance of the aircraft, the better the flight performance. Therefore, the ultra-short takeoff and landing aircraft is also one of the research directions. The basic configuration of the fixed-wing aircraft can be maintained, and the complex structure of the vertical take-off and landing aircraft is avoided; the power plant requirements are also relatively low. Meanwhile, the take-off and landing within a range of dozens of meters are realized by some special designs, and the requirements of the take-off and landing site are basically equivalent to those of the traditional helicopter. By adopting a distributed electric propulsion technology, the ultra-short take-off and landing of the fixed-wing aircraft can be more effectively realized.

Electric short-range/vertical take-off and landing aircraft present situation and disadvantages:

1. the conventional ultra-short-distance take-off and landing aircraft improves the lift force of the aircraft and reduces the take-off and landing speed by increasing the wing area, thereby realizing ultra-short-distance take-off and landing. However, the excessive wing area brings great flight resistance and structural weight, so that the cruising speed of the airplane is low, the cruising energy consumption is high, and the load-carrying capacity is poor.

2. Chinese patent CN211468780U is a short-distance take-off and landing unmanned transport plane, and proposes a duck layout short-distance take-off and landing unmanned transport plane scheme based on a distributed propulsion technology.

The disadvantage is that the aircraft with the duck-type layout has a pneumatic focus closer to the front and far away from the main wing; in order to ensure longitudinal static stability, the center of gravity of the whole airplane is in front of the focus and is far away from the main wing, so that the lift force of the wing generates a large head-lowering moment on the center of gravity during taking off and landing, and the canard wing needs to generate a high positive lift force to balance the head-lowering moment of the wing on the center of gravity. The general canard wing aspect ratio is far smaller than that of the wing, and the lift-increasing effect of the wing lift-increasing device is far better than that of the canard wing, so that the canard wing cannot generate enough positive lift force to balance the head-lowering moment of the wing lift force to the gravity center. The canard configuration is therefore not suitable for use with short take-off and landing aircraft.

3. In the scheme of a vertical take-off and landing aircraft, a Chinese patent CN111688920A VTOL fixed wing flight platform system discloses a vertical take-off and landing aircraft which is realized by using the vertical pulling force of a horizontal propeller. The disadvantages are that: the thrust of the propeller needs to overcome the gravity of the airplane, the power requirement of a propeller power system is high, the power consumption is high, the weight is heavy, and a large amount of electric energy needs to be consumed during taking off and landing. The control, especially the flight control during the flight mode conversion, is complex, so that the effective load of the airplane is small, and the flight distance is short. Particularly, when the battery is landed, the battery is in a low energy state after long-time flight, but the battery is required to be discharged at high power for a short time when the battery finally landed, and the battery is required to have enough discharge capacity. In order to ensure safety, sufficient battery power is generally reserved for landing, which results in further reduction in the endurance of the aircraft.

Therefore, it is difficult for the aircraft platforms in the related art to achieve ultra-short take-off and landing while maintaining high flight performance.

Disclosure of Invention

The application mainly aims to provide a distributed electric propulsion ultra-short take-off and landing fixed-wing aircraft platform to solve the problem that an aircraft in the related art is difficult to realize ultra-short take-off and landing while keeping high flight performance due to the limitation of a pneumatic structure.

In order to achieve the above object, the present application provides a distributed electrically-propelled ultra-short take-off and landing fixed-wing aircraft platform, comprising: a fuselage, a left wing, a right wing;

a plurality of inner high-lift propellers and a plurality of outer high-lift propellers are sequentially arranged on the left wing and the right wing from inside to outside;

the wingtip of the left wing and the wingtip of the right wing are both provided with cruise propellers, and the tail of the fuselage is provided with a tail thrust propeller;

the diameter of the outer high-lift propeller is smaller than that of the inner high-lift propeller, the ratio of the diameter of the inner high-lift propeller to the average aerodynamic chord length of the wing is 0.6-0.8, and the ratio of the diameter of the outer high-lift propeller to the average aerodynamic chord length of the wing is 0.4-0.6;

the distance from the rotating axis of the outer high-lift propeller and the rotating axis of the inner high-lift propeller to the top and bottom of the wing chord line plane is 0.3 to 0.5 times of the diameter of the corresponding propeller, and the distance from the rotating plane of the outer high-lift propeller and the rotating plane of the inner high-lift propeller to the front and back of the wing leading edge is 0.3 to 0.5 times of the diameter of the corresponding propeller.

Further, the ratio of the diameter of the cruise propeller to the corresponding wing tip chord length is between 1 and 2.

Further, in a front view, the rotation direction of the cruise propeller positioned on the left wing is clockwise, and the rotation direction of the cruise propeller positioned on the right wing is counterclockwise.

Further, the machine body is in a laminar flow shape and integrally forms a rotating body, and the maximum thickness position of the machine body is 50% -60% of the length direction of the machine body; the slenderness ratio of the airplane body is 3-4, and the outer surface of the front part of the airplane body except the joint of the nose landing gear is a smooth surface.

Furthermore, the outer side high-lift propeller and the inner side high-lift propeller are set to be foldable propellers which can be attached to the propeller nacelle after being folded.

Further, the distance between the adjacent blade tips of the outer high-lift propeller and the inner high-lift propeller is 5-10cm.

Furthermore, wingtip winglets are further arranged on the outer sides of the left wing and the right wing, and the wingtip winglets have upward bending radians.

The left wing and the right wing are respectively connected with the middle wing;

the trailing edge of the left wing is provided with a left flap and a left flaperon, and the trailing edge of the right wing is provided with a right flap and a right flaperon;

the left flap and the right flap are retreating double-slit flaps, and the left flaperon and the right flaperon are single-slit flaperons with an airfoil spoiler.

Further, the deflection angle of the left flap and the right flap is 30-50 degrees in a take-off state and 55-75 degrees in a landing state;

the left flaperon and the right flaperon are in a cruising state, the left flaperon, the right flaperon and the corresponding wing spoilers are in a neutral position, and the wing spoilers are abutted against the corresponding flaperon;

when the wing flap is used as a wing flap, the left flaperon and the right flaperon can deflect downwards and drive the corresponding wing spoilers to deflect downwards; when the wing spoiler is used as an aileron, the left and right flaperons can deflect upwards and drive the corresponding wing spoilers to deflect upwards, and the wing spoilers are abutted against the corresponding flaperons.

Furthermore, the elevator also comprises a left tail stay tube, a right tail stay tube, a left vertical tail, a right vertical tail, a left rudder, a right rudder, a horizontal tail and an elevator;

the left tail supporting pipe and the right tail supporting pipe are respectively connected with the middle wing, the left vertical tail wing is connected to the left tail supporting pipe, and the rear edge of the left vertical tail wing is provided with a left rudder;

the right vertical tail wing is connected to the right tail stay tube, and the rear edge of the right vertical tail wing is provided with a right rudder;

the horizontal tail is connected to the left vertical tail and the right vertical tail, and an elevator is arranged on the rear edge of the horizontal tail.

In the embodiment of the application, the airplane body, the left wing and the right wing are arranged; a plurality of inner high-lift propellers and a plurality of outer high-lift propellers are sequentially arranged on the left wing and the right wing from inside to outside; the wingtip of the left wing and the wingtip of the right wing are both provided with cruise propellers, and the tail of the fuselage is provided with a tail thrust propeller; the diameter of the outer high-lift propeller is smaller than that of the inner high-lift propeller, the ratio of the diameter of the inner high-lift propeller to the average aerodynamic chord length of the wing is 0.6-0.8, and the ratio of the diameter of the outer high-lift propeller to the average aerodynamic chord length of the wing is 0.4-0.6; the vertical distance between the rotating axes of the outer high-lift propeller and the inner high-lift propeller and the plane of the wing chord line is 0.3-0.5 times of the diameter of the corresponding propeller, and the front-back distance between the rotating planes of the outer high-lift propeller and the inner high-lift propeller and the front edge of the wing is 0.3-0.5 times of the diameter of the corresponding propeller, so that the purpose of combining a distributed electric propulsion technology and an efficient overall aerodynamic design technology of an airplane and improving the maximum lift coefficient of the wing by adjusting the diameters of the outer high-lift propeller and the inner high-lift propeller on the left wing and the right wing is achieved, the lift-increasing effect of the wing is improved, the electric fixed wing airplane can achieve ultra-short-distance lift, the electric fixed wing airplane has higher flight performance and meets the technical effect of transportation requirements of cargo personnel, and the problem that the short-distance lift of the airplane in the related art is difficult to achieve short-distance lift while maintaining high flight performance due to the limitation of the aerodynamic structure is solved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, serve to provide a further understanding of the application and to enable other features, objects, and advantages of the application to be more apparent. The drawings and the description of the exemplary embodiments of the present application are provided for explaining the present application and do not constitute an undue limitation on the present application. In the drawings:

FIG. 1 is a schematic diagram of an axial structure of an aircraft platform according to an embodiment of the present disclosure;

FIG. 2 is a schematic illustration of a forward-looking configuration of an aircraft platform according to an embodiment of the present application;

FIG. 3 is a side view schematic illustration of an aircraft platform according to an embodiment of the present application;

FIG. 4 is a schematic top view of an aircraft platform according to an embodiment of the present application;

FIG. 5 is a schematic illustration of an aft-axis configuration of a high-lift propeller in an aircraft platform, after folding, in accordance with an embodiment of the present application;

FIG. 6 is a schematic front view of a high lift propeller according to an embodiment of the present application after deployment;

FIG. 7 is a schematic front view of a folded high lift propeller according to an embodiment of the present application;

FIG. 8 is a schematic diagram of an axial structure of a high lift propeller after deployment according to an embodiment of the present application;

FIG. 9 is a schematic view of an axial view of a folded high lift propeller according to an embodiment of the present disclosure;

FIG. 10 is a schematic illustration of the configuration of a cruise flap according to an embodiment of the present application;

FIG. 11 is a schematic view of the configuration of a flap in a take-off state according to an embodiment of the present application;

FIG. 12 is a schematic view of the configuration of a landing flap according to an embodiment of the present application;

FIG. 13 is a schematic view of the neutral position of the flaperon according to an embodiment of the present application;

FIG. 14 is a schematic view of the structure of the flaperon underlisting position according to an embodiment of the present application;

FIG. 15 is a schematic view of the structure of the flaperon in an offset position according to an embodiment of the present application;

fig. 16 is a schematic structural view of the neutral position of the elevator according to the embodiment of the present application;

fig. 17 is a schematic view of the structure of the lower offset position of the elevator according to the embodiment of the present application;

fig. 18 is a schematic view of the structure of the upper offset position of the elevator according to the embodiment of the present application;

the aircraft comprises a wingtip winglet 1, cruise propellers 2, right flaperon 3, outside high-lift propellers 4, inside high-lift propellers 5, right wing flap 6, right wing 7, fuselage 8, nose landing gear 9, middle wing 10, right tail support tube 11, rear cabin door 12, left tail support tube 13, tail-push propellers 14, left wing 15, left main landing gear 16, left flaperon 21, left wing flap 22, left vertical tail 23, left rudder 24, right vertical tail 25, horizontal tail 27, elevator 28, right main landing gear 29, wing spoilers 30 and tail spoilers 31.

Detailed Description

In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only partial embodiments of the present application, but not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without making any creative effort shall fall within the protection scope of the present application.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It should be understood that the data so used may be interchanged under appropriate circumstances in order to facilitate the description of the embodiments of the application herein.

In the present application, the terms "upper", "lower", "inner", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings. These terms are used primarily to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to a particular orientation or to be constructed and operated in a particular orientation.

Moreover, some of the above terms may be used to indicate other meanings besides the orientation or positional relationship, for example, the term "on" may also be used to indicate some kind of attachment or connection relationship in some cases. The specific meaning of these terms in this application will be understood by those of ordinary skill in the art as appropriate.

Furthermore, the terms "disposed," "provided," "connected," "secured," and the like are to be construed broadly. For example, "connected" may be a fixed connection, a detachable connection, or a unitary construction; can be a mechanical connection, or an electrical connection; may be directly connected, or indirectly connected through intervening media, or may be in internal communication between two devices, elements or components. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In addition, the term "plurality" shall mean two as well as more than two.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.

Electric aircraft are not only simply powered by a conventional internal combustion engine, but also by an electric motor. The electrification of the airplane can improve the performance of the airplane platform and realize the functions which cannot be realized by the traditional fuel oil power airplane. Especially, the electric propulsion technology has scale independence, and distributed electric power propulsion can be used for replacing centralized electric power propulsion. The distributed electric propulsion technology is combined with the overall aerodynamic design of the airplane, so that the advantages of the electric propulsion technology can be further exerted, and the performance of the airplane platform is improved. The general concept of the application is to combine the distributed electric propulsion technology with the airplane high-efficiency general pneumatic technology to solve the problem that the aircraft in the related technology is difficult to maintain high flight performance and simultaneously takes off and land at an ultra-short distance. Therefore, consideration is mainly given to the distributed electric propulsion technology and the high-lift weight-reduction drag reduction of the airplane.

In the distributed electric propulsion technology, the high lift effect of the wing is increased through the improvement of the propeller, so that the aircraft can take off and land at a short distance. To this end, as shown in fig. 1 to 4, an embodiment of the present application provides a distributed electrically-propelled ultra-short take-off and landing fixed-wing aircraft platform, including: fuselage 8, left wing 15, right wing 7;

a plurality of inner high-lift propellers 5 and a plurality of outer high-lift propellers 4 are sequentially arranged on the left wing 15 and the right wing 7 from inside to outside;

the wingtip of the left wing 15 and the wingtip of the right wing 7 are both provided with cruise propellers 2, and the tail part of the fuselage 8 is provided with a tail thrust propeller 14;

the diameter of the outer high-lift propeller 4 is smaller than that of the inner high-lift propeller 5, the ratio of the diameter of the inner high-lift propeller 5 to the average aerodynamic chord length of the wing is 0.6-0.8, and the ratio of the diameter of the outer high-lift propeller 4 to the average aerodynamic chord length of the wing is 0.4-0.6;

the vertical distance between the rotating axes of the outer high-lift propeller 4 and the inner high-lift propeller 5 and the plane of the wing chord line is 0.3 to 0.5 times of the diameter of the corresponding propeller, and the front-back distance between the rotating planes of the outer high-lift propeller 4 and the inner high-lift propeller 5 and the front edge of the wing is 0.3 to 0.5 times of the diameter of the corresponding propeller.

In this embodiment, the aircraft platform mainly comprises a fuselage 8, a left wing 15, a right wing 7, and propellers mounted on the left wing 15 and the right wing 7, the left wing 15 and the right wing 7 adopt a high aspect ratio straight wing configuration, and the wing profile is a high-lift laminar flow wing profile. The left wing 15 and the right wing 7 have the same propeller position and structure, and are respectively an inner high-lift propeller 5 and an outer high-lift propeller 4 which are sequentially distributed from inside to outside. The outer high-lift propeller 4 and the inner high-lift propeller 5 can be arranged into N sets, the value of N is between 2 and 5, and N is 3 in the embodiment.

In order to enable the wing to have a good high-lift effect under the action of the high-lift propellers, the diameters of the high-lift propellers on the inner side and the outer side and the installation position of the high-lift propellers on the wing are adjusted in the embodiment.

Specifically, as shown in fig. 1, the diameter of the propeller is larger in the present embodiment for the inside high-lift propeller 5, and the diameter of the outside high-lift propeller 4 is smaller. The specific diameters of the inner and outer high-lift propellers further affect the lift-increasing effect, so that the diameter of the inner high-lift propeller 5 is limited to 0.6-0.8 times of the average aerodynamic chord length of the wing (the left wing 15 or the right wing 7), and the diameter of the outer high-lift propeller 4 is limited to 0.4-0.6 times of the average aerodynamic chord length of the wing, so that the wing in the embodiment can have a better lift-increasing effect.

The propeller installation position mainly considers the adjustment of the propeller in the vertical position and the horizontal position, so in the vertical position, the up-and-down distance between the rotating shaft line of the outer high-lift propeller 4 and the plane of the wing chord line is limited to be 0.3-0.5 times of the diameter of the high-lift propeller, and the up-and-down distance between the rotating shaft line of the inner high-lift propeller 5 and the plane of the wing chord line is limited to be 0.3-0.5 times of the diameter of the inner high-lift propeller 5. In the horizontal position, in this embodiment, the front-back distance between the rotation plane of the outer high-lift propeller 4 and the leading edge of the wing is limited to be 0.3-0.5 times of the diameter of the outer high-lift propeller 4, and the front-back distance between the rotation plane of the inner high-lift propeller 5 and the leading edge of the wing is limited to be 0.3-0.5 times of the diameter of the inner high-lift propeller 5.

Different types of high-lift propellers have different high-lift effects in the arrangement in the embodiment, and the distance between adjacent blade tips of the high-lift propellers is set to be 5-10cm in the embodiment so as to adapt to the wing structure in the application.

The embodiment can effectively improve the air flow speed on the surface of the wing, delay the air flow separation and greatly improve the maximum lift coefficient of the wing by pertinently improving the diameter, the vertical installation position and the horizontal installation position of each high-lift propeller. The cruise propellers 2 arranged at the wingtips of the left wing 15 and the right wing 7 can better ensure the cruise performance of the flight platform, and the ratio of the diameter of each cruise propeller 2 to the chord length of the corresponding wingtip is 1-2. The tail-pushing propellers 14 arranged at the tail part of the airplane body 8 can better provide thrust for the flight platform, so that the flight performance of the airplane platform is improved by combining wing structures and all high-lift propellers on the wings, and by utilizing the slipstream lift-increasing effect of the distributed electric propulsion propellers, the ultra-short-distance take-off and landing of the fixed-wing airplane can be realized, and the site adaptability of the airplane similar to vertical take-off and landing is realized. Simultaneously the aircraft platform in this application cruises propeller 2 and tail and pushes away propeller 14 homoenergetic and produce thrust at the in-process that cruises, also can push away the stable flight of thrust that propeller 14 produced through the tail when cruises propeller 2 trouble.

This application has reached and has combined together distributed electric push technique and the high-efficient overall aerodynamic design technique of aircraft, the adjustment is located the outside high lift screw 4 and the inboard high lift screw 5's on left wing 15 and the right wing 7 diameter improves the purpose of the maximum lift coefficient of wing, thereby the lift effect that increases of improvement wing has been realized, make electronic fixed wing aircraft can realize ultrashort distance take off and land, and have higher flight performance, satisfy the technological effect of cargo personnel transportation demand, and then the problem that the aircraft among the correlation technique received the restriction of aerodynamic structure to be difficult to realize the short distance take off and land when keeping high flight performance has been solved.

Further, the cruise propeller 2 on the left wing 15 rotates in the opposite direction to the cruise propeller 2 on the right wing 7. Specifically, the rotation direction (forward view) of the left cruise propeller 2 is clockwise, and the rotation direction (forward view) of the right cruise propeller 2 is counterclockwise. The rotation direction of the wake vortex of the cruise propeller 2 is opposite to the rotation direction of the wing tip vortex of the wing, so that the strength of the wing tip vortex of the wing can be restrained, the induced resistance of the wing is reduced, and the flying efficiency is improved. Meanwhile, the wingtip vortex of the wing can weaken the rotation speed of the propeller wake vortex, and the propelling efficiency of the propeller is improved.

The outer high-lift propeller 4 and the inner high-lift propeller 5 are unfolded to work when the aircraft platform is taking off and landing, so in order to reduce the resistance generated by the high-lift propellers in a cruising state, as shown in fig. 5 to 9, the embodiment sets the inner high-lift propeller 5 and the outer high-lift propeller 4 as foldable propellers, so that the inner high-lift propeller and the outer high-lift propeller can be well folded backwards and attached to the propeller nacelle to reduce the flight resistance when the inner high-lift propeller and the outer high-lift propeller are out of operation.

The above-described embodiments improve the high lift effect of the wing by modifying the direction of the high lift propellers, on the basis of which further aerodynamic design of the fuselage 8 structure is required to enable the aircraft platform to have a high load while maintaining excellent flight performance. Structural weight reduction and aerodynamic drag reduction are constant pursuits of aircraft design, particularly for electric aircraft, in fuselage construction. The available energy of the electric airplane is less due to the limitation of the energy storage performance of the battery, and the loading energy and the flight performance are greatly restricted. In order to improve the performance of electric aircraft, measures must be taken to reduce the weight of the structure and the aerodynamic drag.

Specifically, as shown in fig. 1, in the present embodiment, the fuselage 8 has a laminar flow shape, and the whole fuselage is a rotation body, so that compared with the conventional fuselage 8, the fuselage 8 has a higher internal volume ratio, a smaller surface area under the same volume, and a lighter structure. The maximum thickness position of the fuselage 8 is 50% -60% of the length direction of the fuselage 8; the fuselage 8 has a slenderness ratio of 3-4, preferably 3.1, whereas the slenderness ratio of a conventional fuselage 8 is greater than 6. In order to reduce the drag of the fuselage 8, the outer surface of the front part of the fuselage 8 in this embodiment is a flat surface, specifically, the front 50% of the surface of the fuselage 8 except for the mounting interface of the nose landing gear 9 is not provided with any flap or protrusion, so as to maintain laminar boundary layer flow as much as possible and reduce the flight drag of the fuselage 8 by more than 50%.

For use as a transport vehicle, a rear hatch 12 is mounted to the rear of the fuselage 8 for cargo handling or personnel ingress and egress. While a tail thrust propeller 14 is also mounted on the rear hatch 12. When carrying goods, the aircraft adopts the design of whole packing box. The aircraft landing gear is installed to the lower extreme of fuselage 8, and the aircraft landing gear is fixed three nose undercarriage, including nose undercarriage 9, left main undercarriage 16, right main undercarriage 29. The main landing gear is made of a composite material plate spring landing gear, and the nose landing gear 9 is a free deflection pendulum-reducing nose landing gear 9.

In order to further reduce the wing induced resistance, as shown in fig. 1, in this embodiment, wingtip winglets 1 are further arranged on the outer sides of the left wing 15 and the right wing 7, and the wingtip winglets 1 have upward bending arcs.

As shown in fig. 1 to 4, the aircraft platform in this embodiment further includes a middle wing 10, the middle wing 10 is connected with the fuselage 8 as a whole, and the left wing 15 and the right wing 7 are respectively connected with the middle wing 10;

the trailing edge of the left wing 15 is provided with a left flap 22 and a left flaperon 21, and the trailing edge of the right wing 7 is provided with a right flap 6 and a right flaperon 3;

the left flap 22 and the right flap 6 are retreating double-slit flaps, the maximum deflection angle is large, and the high lift effect is good. As shown in FIGS. 11 and 12, the flaps are deflected by different angles during take-off and landing of the aircraft, with the flaps deflected by about 30-50, preferably 40, during take-off and about 55-75, preferably 65, during landing.

The left flaperon 21 and the right flaperon 3 adopt single-slit flaperons with wing spoilers 30, and the wing spoilers 30 are arranged in front of the flaperons. The wing spoilers 30 can be connected to the corresponding flaperons by links so that they can deflect in coordination with the flaperons to maximize the flaperon efficiency. As shown in fig. 10 and 13, during cruising flight, the left and right flaperons 21, 3 and the corresponding wing spoilers 30 are in a neutral position, so that the cruise drag is minimal. The wing spoilers 30 now ride on the respective flaperons. As shown in fig. 14, when the flaperons are deflected downward, the corresponding wing spoilers 30 are deflected downward to form appropriate gaps with the corresponding flaperons, so as to guide the airflow to flow, increase the lift force of the flaperons and delay the airflow separation. As shown in fig. 15, when the flaperon is deflected up, the corresponding wing spoiler 30 is deflected up, riding on the flaperon.

As shown in fig. 1, the aircraft platform in this embodiment further includes a left tail stay tube 13, a right tail stay tube 11, a left vertical tail 23, a right vertical tail 25, a left rudder 24, a right rudder, a horizontal tail 27, and an elevator 28;

the left tail brace pipe 13 and the right tail brace pipe 11 are respectively connected with the middle wing 10, the left vertical tail wing 23 is connected on the left tail brace pipe 13, and the rear edge of the left vertical tail wing 23 is provided with a left rudder 24;

the right vertical tail 25 is connected to the right tail stay tube 11, and the rear edge of the right vertical tail 25 is provided with a right rudder;

a horizontal rear wing 27 is attached to the left and right vertical rear wings 23 and 25, and an elevator 28 is disposed at the rear edge of the horizontal rear wing 27.

In this embodiment the trailing edge of the vertical tail is arranged with a rudder for the course steering of the aircraft. Because the thrust differential of the wingtip propeller can produce course control effect, a smaller vertical tail wing design can be used, the structural weight is reduced, and the flight resistance is reduced. The rear edge of the horizontal rear wing 27 is provided with an elevator 28 for pitching and trimming the aircraft. Elevator 28 employs a single hinge rudder design with deflectable spoilers. A tail spoiler 31 is arranged in front of the elevator 28. The tail spoiler 31 may deflect in coordination with the elevator 28 to maximize elevator 28 efficiency. As shown in fig. 16, during cruising flight, the elevator 28 and the empennage spoiler 31 are in a neutral position so as to minimize the cruising drag. The tail spoiler 31 now rests on the elevator 28. As shown in fig. 18, when the elevator 28 is deflected upward, the spoiler 31 is deflected upward to form a proper gap with the elevator 28, so as to guide the airflow, increase the lift force of the elevator 28, and delay the airflow separation. As shown in fig. 17, when the elevator 28 is deflected downward, the tail spoiler 31 is deflected downward to abut on the elevator 28.

Meanwhile, on the basis that the thrust differential of the cruise propellers can generate a yaw control effect, the left vertical tail wing and the right vertical tail wing can be smaller, the structural weight can be effectively reduced, and the flight resistance is reduced.

All propellers of the whole aircraft of the aircraft platform are driven by the motor, and the power source of the motor is an onboard power battery, or a fuel cell, or a fuel generator and the like.

The main structural parts of the whole machine comprise skins, frames, beams, stringers, pipes and the like which are all made of composite materials, and part of connecting pieces are made of metal materials at a certain price.

The use process of the airplane platform comprises the following steps:

when the airplane takes off, the flap is in a take-off configuration, and the flaperon is in a take-off configuration. All propellers rotate at maximum rotational speed. The aircraft is pushed to slide away in an accelerating way, the lift force of the wings is increased, the airspeed required for leaving the ground is reduced, and the aircraft can reach the speed of flying away the ground within a short distance. During the period, the ground running deviation correction of the airplane is realized through the differential braking of the main landing gear and the deflection function of the nose landing gear, and the takeoff running distance is less than 50m.

After the airplane takes off, the flaps are gradually retracted to the cruising configuration, and the flaperons are gradually retracted to the cruising configuration. The high-lift propeller stops rotating gradually and is folded, retracted and attached to the propeller nacelle. The aircraft transitions to cruise flight mode. In the cruising flight process, if one side cruising propeller 2 is invalid, the rotating speed of the other side cruising propeller 2 is reduced, the yawing moment of the whole aircraft is reduced, the rotating speed of the tail thrust propeller 14 is increased, and the flight thrust is provided mainly by the tail thrust propeller 14.

During landing, the flaps are in a landing configuration and the flaperons are in a landing configuration. The tail thrust propeller 14 is in a low speed state. The cruise propeller 2 and the inner and outer high-lift propellers are in a landing state (middle rotating speed), the wing lift is increased, and the aircraft ground speed is reduced. After the aircraft is grounded, the cruise propeller 2 and the tail thrust propeller 14 are rapidly reversed to provide a backward deceleration thrust. The high-lift propellers on the inner side and the outer side stop rapidly, and forward thrust and wing lift are reduced. The landing gear wheel brakes are opened rapidly, so that the aircraft decelerates and stops in a short distance, and ultra-short distance landing is realized. The landing and running distance is less than 50m.

This application is through the beneficial effect that above-mentioned institutional advancement obtained:

1. the wing leading edge is distributed to propel the propeller, so that the wing lift force is increased, the full thrust-weight ratio is increased, and the ultra-short distance takeoff and landing of the fixed wing aircraft are realized. Meanwhile, when taking off and landing, under the influence of the slipstream of the propeller, the airflow of the wing is less prone to separation and stalling, and the safety is good.

2. The design of the cruise propeller reduces the induced resistance of the wings, improves the flight efficiency and is more suitable for the use requirement of the electric airplane.

3. The laminar flow fuselage design reduces fuselage resistance (more than 50% of drag reduction) by a wide margin, reduces structure weight, improves aircraft efficiency of cruising, makes it more be fit for the electric aircraft demand.

4. Meanwhile, the laminar flow machine body is small in slenderness ratio, small in specific surface area and large in internal space, and is more suitable for large-volume cargo transportation or improves the riding comfort of people.

5. Distributed electric propulsion improves the redundant safety of the aircraft power system.

6. The thrust differential of the cruise propellers can produce a yaw control effect, so that a smaller vertical tail wing design can be used, the structural weight is reduced, and the flight resistance is reduced.

7. When cruising and flying, the flaperon is under the influence of the slip flow of the wingtip propeller, so that the wingtip stall is not easy to occur, and the maneuverability and the safety are better.

8. The thrust differential of the cruise propeller can generate a yaw control effect, and when the airplane is in a stall and tail spin state, even if the vertical tail is in a failure state, the airplane can be stopped and changed out by the wingtip propeller, so that the safety is better.

9. The electric propulsion power has higher reliability of a power system, smaller vibration, no oil and gas pipeline inside, better maintainability, lower flight cost and smaller vibration and noise. The method is more suitable for the application environment of civil general aircrafts applied in large scale.

10. The plane adopts electric propulsion, is economic and environment-friendly, and does not depend on fossil energy.

11. The whole airplane adopts the conventional layout design, the technology is mature, the reliability is high, and the manufacturing cost is low.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims (9)

1. A distributed electric propulsion ultra-short take-off and landing fixed-wing aircraft platform is characterized by comprising: fuselage, left wing, right wing;

the left wing and the right wing are in a high-aspect-ratio straight wing structure, the wing profile is a high-lift laminar flow wing profile, and a plurality of inner high-lift propellers and a plurality of outer high-lift propellers are sequentially arranged on the left wing and the right wing from inside to outside;

the wingtip of the left wing and the wingtip of the right wing are both provided with cruise propellers, and the tail of the fuselage is provided with a tail thrust propeller;

the diameter of the outer high-lift propeller is smaller than that of the inner high-lift propeller, the ratio of the diameter of the inner high-lift propeller to the average aerodynamic chord length of the wing is 0.6-0.8, and the ratio of the diameter of the outer high-lift propeller to the average aerodynamic chord length of the wing is 0.4-0.6;

the upper and lower distances from the rotating axes of the outer high-lift propellers and the inner high-lift propellers to the plane of the wing chord line are 0.3 to 0.5 times of the diameter of the corresponding propeller, and the front and rear distances from the rotating planes of the outer high-lift propellers and the inner high-lift propellers to the front edge of the wing are 0.3 to 0.5 times of the diameter of the corresponding propeller;

the machine body is in a laminar flow shape and integrally formed into a rotating body, and the maximum thickness position of the machine body is 50-60% of the length direction of the machine body; the slenderness ratio of the airplane body is 3-4, and the outer surface of the front part of the airplane body except the joint of the front part of the airplane body and the nose landing gear is a smooth surface.

2. The distributed electrically-propelled ultra-short take-off and landing fixed-wing aircraft platform of claim 1, wherein: the ratio of the diameter of the cruise propeller to the chord length of the corresponding wingtip is 1-2.

3. The distributed electrically-propelled ultrashort-take-off and landing fixed-wing aircraft platform of claim 2, wherein: in a front view, the rotation direction of the cruise propeller positioned on the left wing is clockwise, and the rotation direction of the cruise propeller positioned on the right wing is anticlockwise.

4. A distributed electrically-propelled ultra-short take-off and landing fixed-wing aircraft platform according to any of claims 1 to 3, wherein: the outside high lift screw with inboard high lift screw sets up to collapsible screw, can laminate on the screw nacelle after folding.

5. The distributed electrically-propelled ultra-short take-off and landing fixed-wing aircraft platform of claim 4, wherein: the distance between the adjacent tips of the outer high-lift propeller and the inner high-lift propeller is 5-10cm.

6. The distributed electrically-propelled ultrashort-takeoff and landing fixed-wing aircraft platform of claim 5, wherein: and wingtip winglets are further arranged on the outer sides of the left wing and the right wing and have upward bending radians.

7. The distributed electrically-propelled ultra-short take-off and landing fixed-wing aircraft platform of claim 6, wherein: the aircraft body is connected with the left wing and the right wing through a connecting piece;

the rear edge of the left wing is provided with a left flap and a left flaperon, and the rear edge of the right wing is provided with a right flap and a right flaperon;

the left flap and the right flap are retreating double-slit flaps, and the left flaperon and the right flaperon are single-slit flaperons with wing spoilers.

8. The distributed electrically-propelled ultrashort-take-off and landing fixed-wing aircraft platform of claim 7, wherein: the deflection angle of the left flap and the right flap in the take-off state is 30-50 degrees, and the deflection angle in the landing state is 55-75 degrees;

the left flaperon and the right flaperon are in a cruising state, the left flaperon, the right flaperon and the corresponding wing spoilers are in a neutral position, and the wing spoilers are lapped against the corresponding flaperons;

when the wing flap is used as a wing flap, the left flaperon and the right flaperon can deflect downwards and drive the corresponding wing spoilers to deflect downwards; when the wing spoiler is used as the aileron, the left and right flaperons can deflect upwards and drive the corresponding wing spoilers to deflect upwards, and the wing spoilers are abutted against the corresponding flaperons.

9. The distributed electrically-propelled ultrashort-take-off and landing fixed-wing aircraft platform of claim 8, wherein: the left tail stay tube, the right tail stay tube, the left vertical tail wing, the right vertical tail wing, the left rudder, the right rudder, the horizontal tail wing and the elevator are also included;

the left tail supporting pipe and the right tail supporting pipe are respectively connected with the middle wing, the left vertical tail wing is connected to the left tail supporting pipe, and the rear edge of the left vertical tail wing is provided with a left rudder;

the right vertical tail wing is connected to the right tail stay tube, and the rear edge of the right vertical tail wing is provided with a right rudder;

the horizontal tail is connected to the left vertical tail and the right vertical tail, and an elevator is arranged on the rear edge of the horizontal tail.

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