Aircraft

Abstract

Main claim: An aircraft (2) having a fuselage (4) which has a nose (6), a tail (8) and a pilot seat (10) or a pilot cabin lying therebetween, having two main wings (12) which each have an inner part (18) closer the fuselage (4) and an outer part (20) further away from the fuselage (4), wherein a vertical flow channel (26) is integrated into each of the two main wings (12), in which vertical flow channel a wing propeller unit (22) is arranged, and wherein a tail unit flow channel (44) is integrated into the tail (8), a tail propeller unit (24) being integrated in the tail flow channel.

Description

[0001] Description

[0002] aircraft

[0003] The invention relates to an aircraft, in particular a person-carrying aircraft.

[0004] In the course of developing smaller aircraft for passenger transport ("air taxis"), various efforts have been undertaken, some reaching the prototype stage. These projects are based on the propulsion concept of drones or multicopters and utilize multiple rotors or propellers arranged in a single plane, pointing downwards vertically or nearly vertically, to generate lift and, by tilting the rotor plane, also propulsion. So far, none of the designs have been entirely convincing. Operational reliability, payload capacity, compactness, range, and flight duration generally leave much to be desired, especially in electrically powered versions.

[0005] The object of the invention is therefore to provide an aircraft which, in a compact design, enables high operational reliability, high payload capacity, long range and long flight duration, in particular with an environmentally friendly electric drive.

[0006] The aforementioned problem is solved according to the invention by an aircraft with the features of claim 1.

[0007] Accordingly, an aircraft is provided with a fuselage having a nose, a tail and a pilot's seat or cockpit located between them, with two main wings, each having an inner part facing the fuselage and an outer part extending away from the fuselage, wherein a vertical flow channel is integrated into each of the two main wings in which a wing-propeller unit is arranged, and wherein a tail flow channel is integrated into the tail of the fuselage in which a tail-propeller unit is arranged.The invention combines lift-generating wings and wing-like fuselage regions for forward flight with a three-point arrangement of preferably fixed propeller units, each designed as a ducted fan / shrouded propeller / impeller and integrated either into the fuselage or the wing. These units can provide lift during vertical takeoff, hovering, and landing, as well as thrust during forward flight. The preferably fixed propeller plane and the elimination of propeller blade pitch control enable a particularly simple design and operation. Instead, the flight mode is controlled by appropriately manipulating the airflow to and from each propeller unit, which can be achieved, for example, by simple flaps, vanes, or similar devices.

[0008] Advantageous configurations are the subject of the dependent claims and the following description.

[0009] A particularly favorable position for the propulsion system, with regard to the aircraft's flight characteristics, is achieved when the respective vertical airflow channel is located in the inner part of the main wing. A particularly stable construction is achieved by making the inner part of the main wing an integral part of the fuselage.

[0010] Advantageously, each vertical airflow channel has a wing air intake located on the upper surface of the associated main wing, preferably equipped with controllable closure elements, in particular in the form of pivoting flaps or louvers. This allows the volume of airflow through this channel to be regulated. Furthermore, each vertical airflow channel expediently has a wing air outlet located on the underside of the associated main wing, preferably equipped with control elements, in particular in the form of pivoting deflection flaps or louvers, that redirect the direction of the exiting airflow, in particular horizontally towards the tail when appropriately positioned. This allows for directional control of the aircraft and, if necessary, accelerated forward flight.

[0011] Advantageously, a front air intake is arranged in the nose of the aircraft, which is aerodynamically connected to the associated vertical airflow channel via a horizontal flow channel. The front air intake is preferably equipped with controllable closure elements, in particular in the form of pivoting flaps or louvers, and preferably opens into the associated vertical airflow channel upstream of the wing-propeller unit. This allows the air supply for the wing-propeller unit to be switched from the wing air intake to the front air intake (or vice versa) or distributed between both paths as needed, depending on the flight situation. Advantageously, the respective horizontal airflow channel is integrated into the fuselage and the main wing, which represents a structurally and aerodynamically favorable solution.

[0012] The tail airflow channel of the aircraft is preferably oriented at least approximately vertically (in any case, preferably more vertically than horizontally) and expediently has a tail air inlet located on the upper side of the fuselage and a tail air outlet located on the underside of the fuselage. The tail air outlet is also advantageously equipped, similar to the respective wing air outlet, with control elements, in particular in the form of pivotable deflectors or vanes, which can redirect the direction of the exiting airflow and thus enable or support directional control.

[0013] In an advantageous embodiment, each wing propeller unit has two counter-rotating propellers arranged one above the other on a single axis. The same preferably applies to the tail propeller unit. By assigning each propeller its own drive, particularly in the form of an electric motor, a high level of reliability is ensured. The counter-rotating arrangement of the propeller pairs prevents imbalances.

[0014] A particularly efficient drive system is achieved when each propeller is a bionic propeller, comprising a stationary, ring-shaped outer part and a rotating inner part within the outer part, with a plurality of curved or bent propeller blades. Preferably, the propeller blades are saw-blade shaped and connected at their outer ends to form a ring structure.

[0015] Preferably, no further aircraft propulsion systems are provided other than the two wing propeller units and the tail propeller unit.

[0016] Furthermore, it is advantageous if smaller auxiliary wings are arranged behind the main wings, which also serve as landing and parking supports.

[0017] The aircraft is preferably designed as a VTOL, especially as an eVTOL, with a hoverbike design being particularly easy and cost-effective to implement.

[0018] The invention also relates to a method for operating an aircraft of the type mentioned, wherein each of the two wing propeller units and the tail propeller unit provide lift during a vertical takeoff or vertical landing or during a hovering flight and thereby lift or keep the aircraft in the air, and wherein each of the two wing propeller units and the tail propeller unit provide thrust during a horizontal flight, while in this case the main wings in particular provide lift.

[0019] An embodiment of the invention is explained in more detail below with reference to the accompanying drawings. It shows:

[0020] FIG. 1 a front view of an aircraft according to the invention, FIG. 2 a top view of the aircraft,

[0021] FIG. 3 a perspective view of the aircraft from a front oblique angle,

[0022] FIG. 4 another perspective view of the aircraft from a frontal oblique angle, here from an elevated viewpoint,

[0023] FIG. 5 a side view of the aircraft,

[0024] FIG. 6 shows a highly simplified section through the aircraft in the area of ​​a wing-propeller unit,

[0025] FIG. 7 a top view of the tail of the aircraft with a tail propeller unit,

[0026] FIG. 8 shows a section through the propeller unit,

[0027] FIG. 9 shows a bionic propeller in top view, and

[0028] FIG. 10 shows the bionic propeller in an exploded perspective view.

[0029] Identical parts in the figures are marked with the same reference symbols.

[0030] The aircraft 2, shown in various perspective views in FIGS. 1 to 5, is designed as a so-called hoverbike with an open seat for one person, the pilot. However, the aerodynamic and propulsion principles described below can also be applied to multi-person aircraft and / or those with an enclosed pilot and / or passenger cabin. Aircraft 2 is designed as a so-called VTOL (Vertical Take-Off and Landing) for vertical take-offs and landings, as well as, if necessary, controlled hovering. Due to its wings and other lift-generating elements, it also possesses the capability for aerodynamic forward flight and, if necessary, gliding.

[0031] The aircraft 2 has a generally teardrop-shaped fuselage 4 with a nose 6 and a tail 8. A pilot's seat 10 is located in a central region between the nose 6 and the tail 8. Between the nose 6 and the pilot's seat 10 are the two main wings 12 (for simplicity sometimes referred to simply as wings), which extend laterally from the fuselage 4 in a symmetrical arrangement, here with a slight negative dihedral angle (viewed from the front). In a rear region behind the pilot's seat 10 are two smaller, horizontal stabilizer-like tail wings 14, here with a slight dihedral angle. In the area of ​​the pilot's seat 10, below the seat and behind the main wings 12, there are also comparatively small auxiliary wings 16, here with a strong negative dihedral angle, whose downward-pointing ends also serve as landing and support legs. Preferably, the auxiliary wings 16, also referred to as landing wings, are resiliently mounted on the fuselage 4 for this purpose.This eliminates the need for complex retractable landing gear or similar devices. An additional landing / parking support is integrated into the underside of the fuselage fairing. Finally, landing / parking supports can also be located on the underside of the wings.

[0032] Each main wing 12 has an inner section 18 (inner wing) with a comparatively thick airfoil and an outer section 20 (outer wing) with a thinner airfoil. The inner section 18 is directly connected to the fuselage 4. In particular, the inner section 18 can form a lateral extension of the fuselage 4, for example, in a one-piece, integral design. The inner section 18 of the wing can thus also be considered a fuselage or body element. The airfoil thickness of the inner section 20 advantageously decreases from the inside out (away from the fuselage 4) to approximate the airfoil thickness of the outer section 20. The outer section 20 of the main wing 12 is connected to the inner section 18 on the outside and can be designed from several mutually adjustable segments, similar to adjustable leading-edge slats (front wing) or aerodynamic flaps.In particular, it can be provided that one or more leading-edge slats of the main wing 12, especially on its outer section 20, can be adjusted via an integrated pivoting mechanism into a highly angled, preferably nearly vertical position or orientation, in which a high aerodynamic braking effect is achieved during forward flight due to the increased drag. This can initiate or support a transition from horizontal forward flight to a vertical landing approach.

[0033] For lift and propulsion, the aircraft 2 has three propeller units 22, 24. One wing-mounted propeller unit 22 is integrated into the inner part 18 of the corresponding main wing 12, and one tail-mounted propeller unit 24 is located at the rear 8 of the fuselage 4 between the two tail wings 14. The two wing-mounted propeller units 22 are arranged symmetrically and are identically dimensioned and designed. Each of the three propeller units 22, 24 has an axis of rotation that is approximately vertically oriented or slightly inclined relative to the vertical (corresponding to an approximately horizontal or slightly inclined propeller plane), relative to the aircraft's normal flight attitude. Thus, in a neutral position of the associated deflection flaps (see below), a substantially downward airflow can be achieved, which can lift the aircraft 2 vertically in the opposite direction according to the reaction principle.The propeller units 22, 24, located (in top view) at the corners of an isosceles triangle, ensure a pitch- and roll-stable take-off and landing orientation.

[0034] More precisely, the respective wing-propeller unit 22 is integrated into the inner part 18 of the associated main wing 12 in the manner of a ducted fan. This means that a substantially vertically oriented vertical flow channel 26, in which the wing-propeller unit 22 is installed in the orientation described above, penetrates the main wing 12 from top to bottom in this area. This means that air is drawn in from above through the inlet opening 28 on the upper surface of the wing, also referred to as the wing air inlet, guided through the flow channel, and expelled by the propeller thrust through the outlet opening 30 on the underside of the wing or the lift-generating fuselage extension.

[0035] The term vertical flow channel 26 here refers to a flow channel oriented vertically or approximately vertically (in any case, more vertically than horizontally) relative to the aircraft's normal flight attitude. The term horizontal flow channel is defined analogously.

[0036] However, this is only one possible flow configuration, which can be modified in a controlled manner during flight by various means. These include the arrangement of a front air intake 32 in the nose 6 of the aircraft 2, which is aerodynamically connected via a two-part horizontal flow channel 34, branching to the left and right and preferably routed within the fuselage fairing, to the respective vertical flow channel 26 containing the propeller unit in the inner part 18 of the main wing 12. The horizontal flow channel 34 preferably opens into the vertical flow channel 26 upstream of the propeller unit 22. This means that a flow connection exists from the front air intake 32 via the wing-propeller unit 22 to the wing air outlet 30 on the underside of the wing.Preferably, this flow connection narrows in cross-section within the horizontal flow channel 34 in the direction of the propeller unit 22 in order to accelerate the airflow.

[0037] Both the front air intake 32 and the wing air intake 28 on the upper surface of the wing are advantageously provided with controllable closure elements 36, in particular in the form of pivotable closure flaps or louvers. Depending on the position of these closure elements 36, an airflow can be supplied to the propeller unit 22 either through the front air intake 32 or through the wing air intake 28 or via both paths (preferably with an adjustable airflow ratio) and expelled through the wing air outlet 30. Furthermore, the vertical flow channel 26 containing the wing propeller unit 22 has control elements 38 in the area of ​​the wing air outlet 30, in particular in the form of pivotable deflection flaps or louvers, by means of which the direction of the expelled airflow can be controlled.In particular, the expelled airflow can be deflected from a vertical to a horizontal direction, specifically rearward towards tail 8, to effect or assist the propulsion of the aircraft 2.

[0038] The tail propeller unit 24 is preferably integrated into a tail section of the fuselage 4 in the manner of a ducted fan, so that air is drawn in from above through an inlet opening on the upper surface of the fuselage 4, also referred to as the tail air inlet 42, guided through a substantially vertically oriented tail airflow channel 44, and expelled through an outlet opening on the underside of the fuselage 4, also referred to as the tail air outlet 46, as a result of the propeller thrust. The tail airflow channel 44 is preferably designed as a vertical airflow channel as specified above. On the inlet side, controllable closure elements, in particular in the form of pivotable flaps or louvers, can be provided. On the outlet side, control elements 48, in particular in the form of pivotable deflector flaps or louvers, can be provided by means of which the direction of the expelled airflow can be controlled.

[0039] The entirety of the controllable closure elements 36 and control elements 38, 48 allows for the targeted control of various operating states. During vertical takeoff (and landing) of the aircraft 2, a flow pattern is preferred in which air is predominantly drawn in through the wing air intake 28 on the upper surface of the wing 12, accelerated by the wing propeller unit 22, and expelled vertically downwards through the wing air outlet 30 on the underside of the wing 12. Simultaneously, the tail propeller unit 24 draws in air from above through the tail air intake 42 and expels it vertically downwards through the tail air outlet 46 on the underside of the rear fuselage. This results in full upward lift.During forward flight, the air for the respective wing-propeller unit 22 is drawn in predominantly or completely through the front air intake 32 with the wing air intake 28 closed, and expelled to the rear through the wing air outlet 30 by means of appropriately adjusted control elements 38. The control elements 48 of the tail air duct 44 with the tail propeller unit 24 are set analogously to achieve maximum thrust. Intermediate states for transitions between vertical takeoff and landing and forward flight are also possible. By appropriately adjusting the control elements 38, 48, lateral air discharge for directional control in all directions during controlled hovering is also preferably possible.

[0040] Each of the three propeller units 22, 24 of the aircraft 2 preferably has two propellers 50 arranged one above the other on a common axis and designed for counter-rotating motion. This is shown schematically in the schematic diagram of FIG. 6, which depicts a section through a wing-propeller unit 22. The two propellers 50 of a propeller unit 22, 24 are preferably each driven by their own drive, in particular their own electric motor, thereby achieving high reliability. The aircraft 2 thus preferably has a total of 2 x 2 = 4 propellers in the main wings 12 and two propellers in the tail, for a total of 6 propellers and the same number of electric motors. A number of associated electrical energy storage devices (e.g., accumulators) or energy generators (e.g., fuel cells) 52 are preferably housed in the fuselage 4 of the aircraft 6, where the motor control unit is also expediently located.Such an electrically powered aircraft 2 is also referred to as an eVTOL.

[0041] The propeller 50 in question is advantageously a so-called bionic propeller, shown in a top view in FIG. 9 and in a perspective exploded view in FIG. 10. The bionic propeller 50 has a rotating inner part 54 with a plurality (e.g., 3 or 4) of slightly bent or curved, saw-like propeller blades 58 within the plane of the propeller, which transition at their outer ends into an interconnected ring-shaped structure. The inner part 54 runs within a stationary outer part 56, which is designed as a ring, with a narrow gap between the ring-shaped structure of the inner part 54 and the ring of the outer part 56. The ring of the outer part 56 is corrugated around its circumference at its lower end (the air outlet side).Due to the described features, the bionic Propeller 50 is exceptionally efficient in converting rotary motion into thrust, across a wide range of rotational speeds. With the same drive power as before, up to 20% higher thrust or lift performance is achieved.

[0042] A front windscreen 60 positioned in front of the pilot's seat 10 and a back protection fairing 62 positioned behind the pilot's seat 10 support the aerodynamic teardrop shape of the fuselage 4 through their design. There is also space under the back protection fairing 62 for a parachute pack, which the pilot carries on his back for his safety.

[0043] Reference symbol list

[0044] 2 aircraft

[0045] 4 Hull

[0046] 6 Bug

[0047] 8 Rear

[0048] 10 pilot seats

[0049] 12 Main wing

[0050] 14 Tail wing

[0051] 16 Auxiliary wing

[0052] 18 Inner part

[0053] 20 Outdoor part

[0054] 22 Wing propeller unit

[0055] 24 Rear propeller unit

[0056] 26 Vertical flow channel

[0057] 28 Wing air intake

[0058] 30 Wing air outlet

[0059] 32 Front air intake

[0060] 34 Horizontal flow channel

[0061] 36 locking element

[0062] 38 Control element

[0063] 42 Rear air intake

[0064] 44 Rear Flow Channel

[0065] 46 Rear air outlet

[0066] 48 Control element

[0067] 50 propellers

[0068] 52 Energy storage / energy generators

[0069] 54 Inner part

[0070] 56 Outdoor part

[0071] 58 propeller blades

[0072] 60 Windscreen

[0073] 62 Back protection panel

Claims

Claims 1. Aircraft (2) with a fuselage (4) having a nose (6), a tail (8) and a pilot's seat (10) or a pilot's cabin located between them, with two main wings (12) each having an inner part (18) facing the fuselage (4) and an outer part (20) extending away from the fuselage (4), wherein a vertical flow channel (26) is integrated into each of the two main wings (12) in which a wing propeller unit (22) is arranged, and wherein a tail flow channel (44) is integrated into the tail (8) in which a tail propeller unit (24) is arranged.

2. Aircraft (2) according to claim 1, wherein the respective vertical flow channel (26) is arranged in the inner part (18) of the main wing (12).

3. Aircraft (2) according to claim 1 or 2, wherein the respective inner part (18) of the main wing (12) forms an integral part of the fuselage (4).

4. Aircraft (2) according to one of the preceding claims, wherein the respective vertical flow channel (26) has a wing air inlet (28) arranged on the upper side of the associated main wing (12).

5. Aircraft (2) according to claim 4, wherein the respective wing air inlet (28) is provided with controllable closure elements (36), in particular in the form of pivotable closure flaps or louvers.

6. Aircraft (2) according to one of the preceding claims, wherein the respective vertical flow channel (26) has a wing air outlet (30) arranged on the underside of the associated main wing (12).

7. Aircraft (2) according to claim 6, wherein the respective wing air outlet (30) is provided with control elements (38), in particular in the form of pivotable deflection flaps or louvers, which control the direction of the exiting air can deflect airflow, especially horizontally towards the rear (8) when in the appropriate position.

8. Aircraft (2) according to one of the preceding claims, wherein a front air inlet (32) is arranged in the nose (6) which is fluidically connected to the associated vertical flow channel (26) via a horizontal flow channel (34).

9. Aircraft (2) according to claim 8, wherein the front air inlet (32) is provided with controllable closure elements, in particular in the form of pivotable closure flaps or louvers.

10. Aircraft (2) according to claim 8 or 9, wherein the respective horizontal flow channel (34) is integrated into the fuselage (4) and into the main wing (12).

11. Aircraft (2) according to one of claims 8 to 10, wherein the respective horizontal flow channel (34) opens upstream of the wing propeller unit (22) into the associated vertical flow channel (26).

12. Aircraft (2) according to one of the preceding claims, wherein the tail flow channel (44) is oriented at least approximately vertically.

13. Aircraft (2) according to one of the preceding claims, wherein the tail flow channel (44) has a tail air inlet (42) arranged on the upper side of the fuselage (4).

14. Aircraft (2) according to one of the preceding claims, wherein the tail flow channel (44) has a tail air outlet (46) arranged on the underside of the fuselage (4).

15. Aircraft (2) according to claim 14, wherein the rear air outlet (46) is equipped with control elements (48), in particular in the form of pivotable deflecting flaps. pen or louvers, which are equipped to redirect the direction of the outgoing airflow.

16. Aircraft (2) according to one of the preceding claims, wherein the respective wing propeller unit (22) has two counter-rotating propellers (50) arranged one above the other on an axis.

17. Aircraft (2) according to one of the preceding claims, wherein the tail propeller unit (24) has two counter-rotating propellers (50) arranged one above the other on an axis.

18. Aircraft (2) according to claim 16 or 17, wherein each propeller (50) is assigned its own drive, in particular in the form of an electric motor.

19. Aircraft (2) according to any one of claims 16 to 18, wherein each propeller (50) is a bionic propeller comprising a stationary annular outer part (56) and an inner part (54) rotating within the outer part (56) with a plurality of curved or bent propeller blades (58).

20. Aircraft (2) according to claim 19, wherein the propeller blades (58) are designed in a saw-blade shape and are connected at the outer ends to form a ring structure.

21. Aircraft (2) according to one of the preceding claims, wherein no further flight propulsion systems are provided other than the two wing propeller units (22) and the tail propeller unit (24).

22. Aircraft (2) according to one of the preceding claims, wherein smaller auxiliary wings (16) are arranged behind the main wings (12), which also serve as landing and parking supports.

23. Aircraft (2) according to any of the preceding claims, which is designed as a VTOL, in particular as an eVTOL.

24. Aircraft (2) according to any of the preceding claims, which is designed as a hoverbike. 25 Aircraft (2) according to one of the preceding claims, wherein each of the two wing propeller units (22) and the tail propeller unit (24) provide lift during a vertical takeoff or vertical landing or during a hover flight and thereby lift or keep the aircraft (2) in the air.

26. Aircraft according to any of the preceding claims, wherein each of the two wing propeller units (22) and the tail propeller unit (24) provide thrust during horizontal flight, while the main wings (12) provide lift.

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