DE102019204970A1 - Functional wing design - Google Patents

Abstract

The present application relates to an aircraft (10) with a fuselage (12) for accommodating at least one person (14) and / or cargo, a wing (16.1, 16.2) to the left and right of a central longitudinal axis (18) running through the fuselage (12) ), which is mirror-symmetrical with respect to the central longitudinal axis (18), and several engines (20.1 ... 20.6) which can be pivoted about a horizontal axis and which can be switched between a horizontal forward flight position and a vertical hover position. A wing leading edge (21.1, 21.2) of the wing (16.1, 16.2) has an acute-angled kink (22.1, 22.2) and an obtuse-angled kink (24.1, 24.2), at which an angle formed by the wing leading edge (21.1, 21.2 ) with the central longitudinal axis (18), changes so that the wing (16.1, 16.2) has a negative sweep of the wing leading edge (21.1, 21.2) between the fuselage (12) and the acute-angled kink (22.1, 22.2) and a positive sweep of the The leading edge of the wing (21.1, 21.2) between the acute-angled kink (22.1, 22.2) and the obtuse-angled kink (24.1, 24.2) and between the obtuse-angled kink (24.1, 24.2) and a wing end (26.1, 26.2), with a trailing edge (23.1, 23.2) of the wing (16.1, 16.2) in the top view has a kink (28.1, 28.2) at which an angle that the wing trailing edge (23.1, 23.2) encloses with the central longitudinal axis (18) changes.

Description

TECHNICAL AREA

The present invention relates to an aircraft with a fuselage for accommodating at least one person and / or cargo, a wing to the left and right of a central longitudinal axis running through the fuselage, which is mirror-symmetrical with respect to the central longitudinal axis, and several engines that can be pivoted about a horizontal axis (transverse axis) which can be switched between a horizontal forward flight position and a vertical hover flight position.

BACKGROUND

Aircraft in the above technical field belong to the group of VTOL aircraft, which can take off and land vertically, but are based on the basic principle of a fixed-wing aircraft. The advantages of these aircraft, in addition to the fact that they do not need a long runway for take-off and landing, and are therefore basically also suitable for use in urban areas, are a more efficient cruise configuration compared to helicopters, using the lift of the wing instead of the engines.

Examples of such aircraft are mainly known from the military sector: Bell Boeing V-22, AgustaWestland AW609, Hawker Siddeley Harrier, McDonnell Douglas AV-8, Jakowlew Jak-38, Boeing X-32 and Lockheed Martin F-35.

The aircraft known from the prior art have several disadvantages. In particular, it is relatively complex to maintain a stable hover attitude. Various concepts are being pursued for this purpose, on the one hand, as in the example of the V-22, large rotors similar to those of helicopters can be used, on the other hand, as in the example of the jet aircraft, sophisticated electronic thrust vector controls are used.

The concepts known from the state of the art are not very useful for use as “air taxis” due to their enormous effort.

DISCLOSURE OF THE INVENTION

Against this background, one object of the present invention is to provide an aircraft in the above technical field that can take off and land vertically, adopt an efficient cruise configuration and is designed as efficiently as possible in order to minimize the control effort and the size of the aircraft so that it is particularly suitable for use as an air taxi in urban environments.

This object is achieved by an aircraft according to claim 1. Advantageous embodiments of the invention emerge from the subclaims.

The aircraft according to the invention initially has a fuselage for accommodating at least one person and / or cargo, a wing to the left and right of a central longitudinal axis running through the fuselage, which is mirror-symmetrical with respect to the central longitudinal axis, and several engines which can each be pivoted about a horizontal axis, which can be switched between a horizontal forward flight position and a vertical hover position.

In connection with the present invention, the horizontal forward flight position means an essentially horizontal alignment of the engine, so that the thrust generated by the engine is aligned essentially horizontally. For aerodynamic reasons, this position can be exactly horizontal (in relation to a horizontal flight position of the aircraft) or also inclined at an angle to the longitudinal axis and / or to the vertical axis. This also applies analogously to the vertical hover position, in which an alignment of the thrust generated by the engine that deviates from an exactly vertical alignment (again based on a horizontal flight position of the aircraft) may be necessary, for example in order to adjust the extent of the required control movements while hovering to limit.

It is further characterized in that a wing leading edge of the wing in a plan view has an acute-angled kink and an obtuse-angled kink, at which an angle that the wing leading edge includes with the central longitudinal axis changes, so that the wing has a negative sweep of the wing leading edge between the Fuselage and the acute-angled kink and a positive sweep of the leading edge of the wing between the acute-angled kink and the obtuse-angled kink and between the obtuse-angled kink and a wing tip, with a trailing edge of the wing in the top view having a kink at which an angle formed by the trailing edge of the wing with the central longitudinal axis, changes.

The wing thus has an outer contour which, in a plan view starting from the fuselage at a first angle to the central longitudinal axis of the fuselage forwards and outwards to a front bend, then at a second angle to the central longitudinal axis from the front bend backwards and outwards to a central bend , then at a third angle different from the second angle from the middle bend backwards and outwards to the Wing tip, then at a fourth angle from the wing tip forward and inward to a rear crease and then from the rear crease backward and inward.

The wing shape that can be defined in this way makes it possible on the one hand to arrange a total of six engines, one per bend, on the wing in such a way that they are uniformly positioned in the form of a hexagon around the aircraft's center of gravity. This enables a great simplification of the control of the aircraft in the hover flight because the individual engines have an easily predeterminable and differentiable effect on the flight attitude in the hover flight. In particular, the power required for hovering can be evenly distributed to all six engines. The arrangement of the engines along the outer contour of the wing increases the respective lever arm of the engine in relation to the center of gravity, which is essentially located in a center point between the engines. Thus, the wing shape according to the invention is advantageous in the hover configuration.

Above all, the acute-angled kink and the associated negative sweep of the leading edge of the wing between the fuselage and the acute angle means that the effective wing area is relatively far forward compared to the fuselage, because the leading edge of the wing initially runs forward from the wing root on the fuselage. The local aerodynamic pressure point of the wing, i.e. the point at which the lift force of the wing is summarized analogously to the center of gravity is around 25% of the mean aerodynamic wing depth (MAC). Due to the wing shape according to the invention, the aerodynamic pressure point of the wing can be positioned overall along the central longitudinal axis in such a way that it essentially coincides with the center of gravity of the aircraft or is at least very close to it. This results in a particularly efficient cruise configuration of the aircraft because the aerodynamic pressure point and center of gravity do not have to be brought together, or at least not very far, by aerodynamic measures such as horizontal stabilizers and the like. This saves energy in the cruise configuration or enables a higher cruise speed with the same energy consumption. Thus, the wing shape according to the invention is also advantageous in the cruise configuration.

The negative sweep of the leading edge of the wing between the fuselage and the acute angle also makes it possible for the occupants to be restricted in their downward visibility, particularly during take-off and landing, to be comparatively minor. This is possible because the negative sweep of the leading edge of the wing also results in an arrangement of the wing root that is relatively far to the rear, at which the wing contacts the fuselage. In this way, the cabin glazing in the front area of the aircraft can be pulled far back and down and reveal the view downwards similar to that of helicopters. This is especially important for a manual approach while hovering.

Finally, the negative sweep of the leading edge of the wing between the fuselage and the acute angle enables easy entry into the fuselage from the front, because the wing root, which is far back, allows a large fuselage opening in the area of the aircraft nose.

In a preferred embodiment, the aircraft has six of the engines, one engine being arranged on the wing at each of the bends.

This configuration of the aircraft leads to the advantageous effect that the engines are very well distributed over the outer contours of the wing and thus enable particularly efficient and easy control of the hovering state. The arrangement of the engines at the kinks also allows the engines to take in and expel air very freely without being restricted by the wing, fuselage or other parts of the aircraft. Among other things, this results from the fact that the kinks each allow a large amount of free space at the edge of the wing or a stable attachment of the corresponding engine to the wing. In particular, switching between the horizontal forward flight position and the vertical hovering position of the engines is particularly unproblematic in this preferred embodiment, as this enables the air jet generated by the engines to flow freely in any orientation or at least in all relevant orientations of the engines.

As an alternative to this, the engines can also be arranged at locations other than the bends of the wing.

In a preferred embodiment, the engines are arranged in such a way that they define corners of an imaginary hexagon in the plan view, the geometric center of gravity of the hexagon coinciding with the center of gravity of the aircraft. This arrangement of the engines makes it possible to simplify the control of the aircraft particularly well when it is hovering. Alternatively, more or fewer engines can be used and the geometric center of gravity of the polygon formed by the engines in the top view can also lie outside the center of gravity, so that different power settings of different engines keep the aircraft safely in the hover position.

The wing is preferably designed in such a way that the center of gravity of the aircraft is arranged at the pressure point of the aircraft and in particular at 25% of the average aerodynamic wing depth (MAC) of the wing. In this way, a particularly efficient cruise configuration of the aircraft can be adopted because the aerodynamic pressure point of the wing can essentially coincide with the center of gravity of the aircraft, which makes resistance-generating compensation means such as horizontal stabilizer, elevator, trim, baffles, etc. at least partially unnecessary.

Alternatively, however, a different design of the wing or other parts of the aircraft can also be provided, which for example lead to effects which in individual cases can be more important than an efficient cruise configuration.

In a preferred embodiment, the engines are arranged in different vertical positions relative to the wing, so that at least one of the engines is arranged above the center of gravity of the aircraft and at least one other of the engines is arranged below the center of gravity of the aircraft. As an alternative to the wing, other parts of the aircraft, for example the fuselage, can also serve as a reference for the vertical position of the individual engines. The preferred embodiment of the invention achieves advantageous dynamic properties in the horizontal acceleration. In addition, this arrangement allows the engines to be used during the transition between cruise and hovering and also during cruise to stabilize the aircraft about the transverse axis.

Particularly preferably, the same number of engines are arranged above and below the center of gravity of the aircraft. It is further preferred that the propulsive force of the overall engines arranged above and the engines arranged overall below is dimensioned to be the same. In this way, the engines can bring their full potential propulsive power to bear without significant compensation forces being required to maintain the flight attitude.

Alternatively, most or all of the engines can be arranged below, to the side or above the center of gravity of the aircraft. Strong changes in performance in the cruise configuration, in which the engines are aligned horizontally, may then have to be compensated for by control surfaces or the like so as not to produce a significant change in flight attitude, which is known from the prior art of fixed-wing aircraft.

The fuselage advantageously has a transparent dome in its front area in the direction of flight, which extends backwards and downwards to the left and right of the central longitudinal axis at least as far as a wing root at which the wing contacts the fuselage. In this way, the occupants can see largely unrestrictedly not only forwards, but also at a wide angle to the sides and downwards, without the technical help of cameras etc., which is of great help in particular when manually approaching a landing field.

In a preferred embodiment, the engines are electric engines. This makes it possible to use a large number of compact engines without very complex mechanical power transmission devices.

In a preferred embodiment, the fuselage has an entry opening in the fuselage nose so that the at least one person or cargo can enter the fuselage from the front or be loaded into the fuselage. Entry from the front or loading from the front has the advantage of largely undisturbed access to the fuselage of the aircraft. So it is not necessary to climb over the wing, which would be necessary in the case of a fundamentally possible side entry.

The measures described above provide an aircraft that can take off and land vertically, adopt an efficient cruise configuration and is efficiently designed to keep the control effort and the size of the aircraft as low as possible, so that it is particularly suitable for use as a Air taxi is suitable in urban environments.

Further advantages and developments of the invention emerge from the following description of the figures and the entirety of the claims.

Figure list

• 1 Figure 3 shows a side view of a preferred embodiment.
• 2 FIG. 14 shows a bottom view of the preferred embodiment of FIG 1 .

WAYS OF CARRYING OUT THE INVENTION

In the following description, the same reference numerals are used for the same or corresponding elements and a repetitive description is largely avoided.

1 shows a side view of a preferred embodiment of an aircraft 10 with a trunk 12 and a left wing 16.2 . The in 2 shown right wing 16.1 is in 1 Not shown. At one end of a wing 26.2 shows the wing 16.2 a winglet 34.2 on, being another winglet 34.1 at an opposite wing tip 26.1 in 1 not, but in 2 is shown. There is a vertical tail unit at the end of the fuselage 32 and in the front area of the fuselage in the direction of flight 12 there is a see-through dome 30th , in the 1 is shown in the closed position and from the in 1 an open position is also indicated. In a departure from the embodiment shown, it is also possible to use only one vertical stabilizer without winglets or only winglets at the wing ends without a vertical stabilizer.

In 1 is a person 14th depicted in the position of a pilot or passenger and it is a line of sight 15th illustrated up to which the person 14th through the transparent dome 30th can see down without obscuring parts of the fuselage 12 or the dome 30th to be disabled.

1 further shows three engines 20.4 , 20.5 , 20.6 who are on the left wing 16.2 each via an engine nacelle 38.6 , 38.5 , 38.4 are attached. The rest, in 2 shown three engines 20.1 , 20.2 , 20.3 each have an engine nacelle 38.1 , 38.2 and 38.3 on the right wing 16.1 appropriate. In the two front in 1 recognizable engine nacelles 38.6 , 38.5 as well as the in 2 shown, symmetrically with respect to the central longitudinal axis 18th opposite engine nacelles 38.1 , 38.2 are also support legs 40.1 , 40.2 , 40.5 , 40.6 arranged in 1 shown in the extended landing configuration and located in or on the engine nacelles 38.1 , 38.2 , 38.5 , 38.6 let it work.

In 1 it can be seen that the front left engine 20.6 opposite the left wing 16.1 is located low, the middle left engine 20.5 opposite the left wing 16.1 as deep as the front left engine 20.6 is arranged, but the rear left engine 20.4 opposite the left wing 16.1 is arranged high. The right engines 20.1 ... 20.3 are arranged mirror-symmetrically. This allows the thrust vector of the rear engines 20.3 , 20.4 in the cruise configuration (not shown), in which the engines are oriented horizontally and their recoil backwards (in 1 to the right) above the in 2 shown focus SP (in 1 not shown) of the aircraft while the thrust vector of the center and front engines 20.1 , 20.2 , 20.5 , 20.6 below the center of gravity SP attacks. Depending on the lever arm, ie vertical distance from the center of gravity SP can use the thrust vectors of the engines 20.1 ... 20.6 be very large without creating a large upward or downward pitching moment, which otherwise would have to be compensated for by control surfaces or baffles, weight shifting or the like, in order to maintain the flight attitude as far as possible in the event of strong changes in engine power.

2 Figure 10 shows a bottom view of the aircraft 10 and clearly illustrates a preferred outer contour of the wing 16.1 , 16.2 . A wing leading edge runs after this 21.1 , 21.2 of the wing 16.1 , 16.2 first from the trunk 12 and the central longitudinal axis 18th at a first angle to the central longitudinal axis 18th forward and outward to a front, acute-angled kink 22.1 , 22.2 , then at a second angle to the central longitudinal axis 18th from the front acute angled kink 22.1 , 22.2 backwards and outwards to a central obtuse-angled kink 24.1 , 24.2 , then at a third angle different from the second angle from the middle obtuse-angled kink 24.1 , 24.2 backwards and outwards to the wing tip 26.1 , 26.2 . A wing trailing edge 23.1 , 23.2 runs at a fourth angle from the wing tip 26.1 , 26.2 forward and inward to a rear obtuse-angled kink 28.1 , 28.2 and then from the rear obtuse-angled kink 28.1 , 28.2 backwards and inwards to get into the torso 12 and the rudder 32 to pass over.

At the front acute angled crease 22.1 , 22.2 are the engine nacelles 38.1 , 38.6 of the two front engines 20.1 , 20.6 appropriate. By positioning them at the front acute-angled bend 22.1 , 22.2 they are way ahead of the center of gravity SP of the aircraft 10 positioned and can be used together with the at the rear obtuse-angled kink 28.1 , 28.2 about their engine nacelles 28.3 , 38.4 attached engines 20.3 , 20.4 that are way behind the center of gravity SP of the aircraft 10 are positioned the aircraft 10 well its by its center of gravity SP Balance the running transverse axis.

The middle obtuse-angled kink 24.1 , 24.2 is along the central longitudinal axis 18th at a point that is roughly the position of the center of gravity SP of the aircraft 10 corresponds. This means they can use their engine nacelles 38.2 , 38.5 at this obtuse-angled kink 24.1 , 24.2 on the wing 16.1 , 16.2 attached engines 20.2 , 20.5 The plane 10 well its by its center of gravity SP Balance the running longitudinal axis. Thus, the hover attitude of the aircraft 10 through the six engines 20.1 ... 20.6 can be controlled well and without great technical control effort. This is possible despite the relatively compact size of the engines 20.1 ... 20.6 and empower the plane 10 thus especially for use as an air taxi or the like in an urban environment.

In 2 are also designed as elevon control surfaces 36.1 , 36.2 pictured with which the aircraft 10 in the cruise configuration where the lift is mainly due to the wing 16.1 , 16.2 can be controlled.

List of reference symbols

10

plane

12

hull

14th

person

15th

Line of sight

16.1, 16.2

wing

18th

Central longitudinal axis

20.1 ... 20.6

Engine

21.1, 21.2

Wing leading edge

22.1, 22.2

acute angled kink

23.1, 23.2

Trailing edge of the wing

24.1, 24.2

obtuse angled kink

26.1, 26.2

Wingtip

28.1, 28.2

obtuse angled kink

30th

dome

32

Vertical stabilizer

34.1, 34.2

Winglet

36.1, 36.2

Control surface

38.1 ... 38.6

Engine nacelle

40.1, 40.2, 40.5, 40.6

Support leg

SP

main emphasis

Claims (8)

Airplane (10) with a fuselage (12) for accommodating at least one person (14) and / or cargo, a wing (16.1, 16.2) on the left and right of a central longitudinal axis (18) running through the fuselage (12), which with respect to the The central longitudinal axis (18) is mirror-symmetrical, and several engines (20.1 ... 20.6) which can be pivoted about a horizontal axis and which can be switched between a horizontal forward flight position and a vertical hovering flight position, characterized in that a leading edge (21.1, 21.2) of the wing (16.1 , 16.2) has an acute-angled kink (22.1, 22.2) and an obtuse-angled kink (24.1, 24.2) in a top view, at which an angle that the wing leading edge (21.1, 21.2) includes with the central longitudinal axis (18) changes, see above that the wing (16.1, 16.2) has a negative sweep of the wing leading edge (21.1, 21.2) between the fuselage (12) and the acute-angled bend (22.1, 22.2) and a positive sweeping of the wing leading edge (21.1, 21.2) between The acute-angled kink (22.1, 22.2) and the obtuse-angled kink (24.1, 24.2) and between the obtuse-angled kink (24.1, 24.2) and a wing end (26.1, 26.2), with a wing trailing edge (23.1, 23.2) of the wing (16.1 , 16.2) has a kink (28.1, 28.2) in the top view, at which an angle that the wing trailing edge (23.1, 23.2) includes with the central longitudinal axis (18) changes. Airplane (10) after Claim 1 , wherein the aircraft (10) has six of the engines (20.1 ... 20.6) and where each of the kinks (22.1, 22.2, 24.1, 24.2, 28.1, 28.2) has one engine (20.1 ... 20.6) on the wing ( 16.1, 16.2) is arranged. Airplane (10) after Claim 1 or 2 , wherein the engines (20.1 ... 20.6) are arranged such that they define corners of an imaginary hexagon in plan view, a geometric center of gravity of the hexagon coinciding with a center of gravity (SP) of the aircraft (10). Aircraft (10) according to one of the preceding claims, wherein the wing (16.1, 16.2) is designed such that the center of gravity (SP) of the aircraft (10) is arranged at 25% of an average aerodynamic wing depth of the wing (16.1, 16.2). Aircraft (10) according to one of the preceding claims, wherein the engines (20.1 ... 20.6) are arranged in different vertical positions relative to the wing (16.1, 16.2), so that at least one of the engines (20.1 ... 20.6) is above the Center of gravity (SP) of the aircraft (10) is arranged and at least one other of the engines (20.1 ... 20.6) is arranged below the center of gravity (SP) of the aircraft (10), preferably the same number of engines (20.1 ... 20.6) are arranged above and below the center of gravity (SP) of the aircraft (10). Aircraft (10) according to one of the preceding claims, wherein the fuselage (12) has a transparent dome (30) in its front area in the direction of flight, which extends to the left and right of the central longitudinal axis (18) at least up to a wing root on which the wing (16.1, 16.2) contacts the fuselage (12), extends backwards and downwards. Aircraft (10) according to one of the preceding claims, wherein the engines (20.1 ... 20.6) are electric engines. Aircraft (10) according to one of the preceding claims, wherein the fuselage (12) has an entry opening in the fuselage nose so that the at least one person (14) or cargo can enter the fuselage (12) from the front or be loaded into the fuselage (12).

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