DE102020007836A1 - Aircraft with wings and operating procedures - Google Patents

Abstract

Aircraft (2), comprising a fuselage (6) and at least two main rotors (8, 10) peripherally attached thereto, which enable the aircraft (2) to take off and land vertically, with two at least partially foldable rotors attached to the side of the fuselage (6). wings (34).

Description

The invention relates to an aircraft comprising a fuselage and at least two main rotors attached peripherally thereto, which enable the aircraft to take off and land vertically. It also relates to an operating procedure.

The birth of electric vertical take-off and landing (eVTOL) aircraft has led to a variety of new concepts in urban transportation and traffic. Appropriate rotors or propellers are essential for providing the functionalities of vertical take-off and landing.

The size, number and position of the rotors or propellers of an eVTOL have a major impact on the safety, energy efficiency and noise reduction of the aircraft and are the decisive factors in obtaining certification from aviation safety authorities such as EASA and FAA. There are currently various concepts for this.

For example, four rotors can be arranged in the four corner areas of an eVTOL, which provide the necessary lift and propulsion in different flight scenarios. The disadvantage of this concept is that in the event of a malfunction or failure of one of the corner rotors, it is not possible to take off or land safely or accurately.

In other versions, the eVTOL has a large main rotor located in the center of the fuselage and essentially at the center of gravity of the aircraft, with four small propellers located at the ends of the wings or winglets. The main rotor essentially provides the lift when taking off and landing the aircraft, while the four small rotors are mainly used to balance the aircraft. The disadvantage here is that if the main rotor fails, it is not possible to take off or land safely or accurately.

Conventional aircraft do not have vertical thrust rotors. The wings serve to generate lift so that the aircraft can reach and maintain a desired altitude.

In contrast, in the eVTOL industry, wings are optional parts since lift can be achieved with the help of rotors. In addition, the combination of rotors and wings is difficult, since it must be prevented that the wings negatively influence the airflow through the wings, or vice versa, that the rotors negatively influence the airflow along the wings, whereby the maximum possible lift through the wings is not achieved .

There are different technologies available for the rotors. They can be attached to different positions on the eVTOL resulting in many different designs for eVTOL.

A first group of eVTOL have no wings, only rotors. These are generally less efficient and unsafe than winged eVTOLs, and if the rotors malfunction, they cannot land safely. A second group of eVTOLs have wings. The rotors are not attached to the wings, and the entire wings are used to generate lift.

Aircraft such as eVTOL are mainly to be used in cities where landing and take-off sites have to be provided in a confined space. Known concepts of eVTOL have long wings with attached rotors, so that a large take-off or landing area is required and the efficiency of the wings is also reduced.

From the WO 2020/141513 A2 a vertically taking off and landing aircraft is known which has rotors which are arranged on the fuselage or the wings.

the DE 10 2015 001 704 B5 describes a vertical takeoff capable aircraft with a support structure that includes a fuselage and two pylons.

The invention is based on the object of providing an aircraft which can land more safely in the event of a malfunction of the rotors and which has a longer range and reduced energy consumption. Furthermore, a corresponding operating method is to be provided.

With regard to the aircraft, this object is achieved according to the invention in that the aircraft has two wings attached laterally to the fuselage.

Advantageous configurations of the invention are the subject matter of the dependent claims.

The invention is based on the consideration that high safety, range and high energy efficiency are important for the acceptance and use of aircraft in urban air traffic. At the same time, the space available for landing and take-off sites in the urban environment is very limited.

As has now been recognized, these requirements can be met simultaneously by the aircraft has wings attached to its sides. By using wings, additional lift can be generated during flight operations, so that this does not have to be provided exclusively by the rotors or propellers. If one or more of the rotors fails, the aircraft essentially still has the flight characteristics of an airplane and can land safely.

It is essential for the invention that the main rotors are attached directly to the fuselage and allow the aircraft or eVTOL to take off and land vertically. It differs from known aircraft in which one or more rotors are attached to the wings or in which vertical take-off and landing is not possible, since the rotors function essentially as propellers.

The respective wing can preferably be folded up at least partially. The wings are not strictly needed for vertical takeoff and landing maneuvers, so they can be folded for those operations, reducing the space required.

The respective wing advantageously has at least one joint on which a part of the respective wing can be folded upwards.

An electric motor for folding up part of the wing is preferably provided on each wing.

The shape of the respective wing is advantageously designed in such a way that it does not overlap with the respectively adjacent rotor in a plan view. This ensures that the blades do not block the air that is supposed to reach and flow through the rotors. In this configuration, the vanes reduce the efficiency of the rotors very little.

The respective wing is advantageously arranged under the respective adjacent rotor in a vertical direction of the fuselage. As a result, the wind, which should flow through the rotors or flow over and under the wings, is separated very well in the cruising phase, so that the rotors and wings each achieve their maximum efficiency.

The respective wing preferably has at least one aileron and/or at least one take-off and loading flap. As with conventional aircraft, these control surfaces and/or flaps can be used to reduce speed, change altitude, and turn the aircraft left or right, depending on the combination and configuration.

In a preferred embodiment, the respective wing has exactly two take-off and landing flaps. In a further preferred embodiment, each wing has an aileron and a take-off and landing flap. The respective wing preferably has a winglet.

The wing width at the fuselage mounted position is advantageously between 65% and 140% of the nearest horizontal distance (parallel to a longitudinal axis of the fuselage) between the rotors on one side, i.e. the peripheral distance between the outer regions of the rotors. This width advantageously changes to 48% and 110%, in a line parallel to the line of closest spacing, at a spacing of the fuselage just below a peripheral spacing between the rotors.

In the vertical direction, the distance between the wings and the main rotors is preferably between 51% and 100% of the height of the fuselage of the aircraft or eVTOL.

With regard to the method, the above-mentioned object is achieved according to the invention in that the wings are folded in to start the aircraft, and the wings are moved into a fully unfolded position after the aircraft has taken off.

Preferably, the wings are folded up prior to landing, reducing the length of the overall wings and minimizing air pressure on them. Advantageously, the wings are folded when the aircraft needs to fly in a narrow airway or when space is at a premium, such as when flying between buildings.

The advantages of the invention are, in particular, that when the wings are opened or unfolded and the rotors malfunction, the aircraft or eVTOL can still fly like a normal aircraft and land in a safe place. Therefore, the wings increase the safety of the eVTOL and thus the chance of receiving certification from the organizations responsible for safe flights.

Further advantages of the invention are that energy consumption can be reduced by using the wings. As a result, longer distances can be achieved and charging frequencies can be reduced. This keeps the cost of a flight low.

The aircraft described combines the advantages of vertically taking off and landing aircraft (small space required for takeoff and landing) and due to the wings the advantages of conventional aircraft. By folding up the wings, the space required for take-off and landing is no greater than for eVTOLs without wings.

• 1 ein Fluggerät mit eingeklappten Flügeln in einer seitlichen Ansicht;
• 2 das Fluggerät gemäß 1 in einer Vorderansicht;
• 3 das Fluggerät gemäß 1 in einer perspektivischen Ansicht von oben;
• 4 das Fluggerät gemäß 1 mit ausgeklappten Flügeln in einer Draufsicht;
• 5 das Fluggerät gemäß 1 mit ausgeklappten Flügeln in einer Vorderansicht;
• 6 das Fluggerät gemäß 1 mit ausgeklappten Flügeln in einer perspektivischen Ansicht von oben; und
• 7 das Fluggerät gemäß 1 mit ausgeklappten Flügeln und angewinkelten Heckrotoren in einer perspektivischen Ansicht von oben. perspektivischen Ansicht von oben.

An embodiment of the invention is explained in more detail with reference to a drawing. It shows in a highly schematic representation:

• 1 an aircraft with folded wings in a side view;
• 2 the aircraft according to 1 in a front view;
• 3 the aircraft according to 1 in a perspective view from above;
• 4 the aircraft according to 1 with unfolded wings in a plan view;
• 5 the aircraft according to 1 with unfolded wings in a front view;
• 6 the aircraft according to 1 with unfolded wings in a perspective view from above; and
• 7 the aircraft according to 1 with folded wings and angled tail rotors in a perspective view from above. perspective view from above.

Identical parts are provided with the same reference symbols in all figures.

one in the 1-7 The aircraft 2 shown has a fuselage 6 on which four main rotors, namely two front rotors 8 and two rear rotors 10, are attached peripherally, in particular at its imaginary corners. The fuselage 6 has a tail fin 14 at its rear, to which a rudder 16 is attached. The aircraft 2 has a landing gear 20 with rollers 24 . Seen in a longitudinal direction 30 between the rotors 8, 10, wings 34 are attached to the sides of the fuselage 6, with an outer wing part 44 being able to be folded up at a joint 40 in each case. As in 2 recognizable, the outer wing parts 44 have winglets 50 .

The two rear rotors 10 can each be rotated forwards and advantageously also backwards about an axis perpendicular to the longitudinal axis. In the preferred embodiment of the aircraft 2 shown here, only the rear rotors 10 and not the front rotors 8 can be rotated. In other preferred embodiments, the front rotors 8 can also be rotatable.

The main rotors 8, 10 are each preferably attached to the fuselage by a shaft. The rotors 8, 10 are rotated as the shafts are rotated by electric motors, respectively. The relative angles between the rotors 8, 10 and the fuselage 6 and also the forward or backward rotating speed of the rotors 8, 10 are controlled by the electric motors rotating the respective shafts.

As in 3 As can be seen, the aircraft 2 has at least one additional rotor 60 arranged on the fuselage 6 . In the present exemplary embodiment, exactly one additional rotor 60 is provided. In an alternative, preferred embodiment, two additional rotors 60 arranged coaxially and at a vertical distance from one another can be provided. The additional rotor 60 is arranged essentially at the center of gravity of the aircraft 2 so that when it is actuated it exerts little or no torque on the aircraft 2 .

The aircraft 2 has a control and/or regulation unit 66 for controlling and/or regulating the rotors 8, 10 and 60. The use of the additional rotor 60 in various flight dynamic situations is described in more detail below. When the aircraft 2 takes off or lands, the additional rotor 60 is activated and its speed is increased in the process, so that it provides a desired lift for the aircraft 2 .

When using exactly one additional rotor 60 with a radius of approx. 70% of the radius of the main rotors, i.e. the front rotors 8 and the rear rotors 10, and a rotational or angular speed that is approx. 100-150% faster than that of the main rotors, can be reduced about 5% to 12% of the load on the main rotors. If the radius is about 100% of the radius of the main rotors, it can reduce about 20% of the load on the main rotors at the same rotation speed. When using two additional rotors 60, depending on their vertical distance, these above values approximately double. Of course, the specific values depend, among other things, on the specific radii and the shape of the rotors 8, 10, 60, the electric motors used and the total weight of the aircraft 2.

Likewise, when landing, the additional rotor 60 is activated in order to generate lift. In both cases, the rotational speed of the main rotors 8, 10 can be reduced compared to the case without an additional rotor 60, so that noise from the aircraft 2 can be reduced.

The additional rotor 60 can be used to stabilize the aircraft 2 in a fallback level of the aircraft 2 in which one or more of the main rotors 8, 10 are no longer performing their proper function. For this purpose, the control and/or regulating unit 66 controls the additional rotor 60 in such a way that the aircraft 2 can be held at the altitude desired by the pilot during a landing, so that the still functioning Rotors 8, 10 can be used to stabilize the attitude of the aircraft 2 and to maneuver to a safe landing site. Likewise, if the main rotors 8, 10 fail during the vertical take-off process, the additional rotor 60 can be used to avoid altitude stabilization of the aircraft 2 or unstable sagging, so that a safe emergency landing can be initiated.

In flight operation after vertical take-off in the transition to a forward-directed flight, the rear rotors 10 are rotated so that they generate propulsion as well as lift. In order to prevent unwanted sagging in eVTOL aircraft without an additional rotor 60, the rotational speed of the rotors must be increased in this case, which can lead to an unstable flight situation and an increased noise level. Since the respective additional rotor 60 reduces the load on the other rotors 8, 10, the rear rotors 10 can rotate forwards or backwards more quickly and easily, which enables a quick transition from lift to propulsion and from cruising to landing. Energy can also be saved with the help of the additional rotor 60, since the angle and the time of this transition (takeoff after flying or flying after landing) can be reduced. In the case of the aircraft 2 presented here, the additional lift can take place with the aid of the additional rotor 60, as a result of which a stable transition from a hover situation to a flight situation that is pleasant for the passengers is created.

If an evasive maneuver is necessary, the additional rotor 60 is controlled by the control and/or regulating unit 66 in order to bring the aircraft 2 to a desired altitude or to hold it there.

As in 4 As can be seen, seen from above, the wings 34 do not overlap with the propellers or rotors 8, 10. This ensures that the air flowing through the respective rotor 8, 10 is not obstructed or deflected by the wing. Because the wings are attached to the bottom of the fuselage 6, the air flowing over and under the wings 34 is not impeded by the rotors 8,10. The lift provided by the wings 34 is thus not reduced or adversely affected by the rotors.

In the preferred embodiment shown, the respective wing 34 has two take-off and landing flaps 70 (flaps). In other preferred embodiments, only one take-off and landing flap 70 can be provided on each of the two wings 34 . In a further preferred embodiment, the respective wing 34 has a take-off and landing flap 70 and an aileron.

The wing width at the fuselage mounted position is advantageously between 65% and 140% of the nearest horizontal distance (parallel to a longitudinal axis of the fuselage) between the rotors on one side, i.e. the peripheral distance between the outer regions of the rotors. This width advantageously changes to 48% and 110%, in a line parallel to the line of closest spacing, at a spacing of the fuselage just below a peripheral spacing between the rotors.

In a vertical direction 32 or height direction, see for example 5 , the distance between the wings and the main rotors is preferably between 51% and 100% of the height of the fuselage of the aircraft 2 or eVTOL. The hull 6 is preferably made essentially of carbon fiber reinforced plastic. Typical dimensions of the hull 6 are approximately 2m x 2m x 8m.

The wings 34 are at least partially folded up for take-off and landing, with a wing part 44 adjoining a winglet 50 preferably being folded up. Since the aircraft 2 takes off and lands vertically, lift from the wings is not required. By folding up the wings 34, the space required for the aircraft 2 is reduced. This is particularly beneficial in urban areas where space for airport hubs is limited.

The wings 34 are deployed after a launch phase at or before the start of forward flight. They generate lift when flying forward, so that less lift has to be generated by the main rotors 8, 10, which means that energy can be saved.

The wings 34 are also folded out if a malfunction of one or more of the main rotors 8,10 occurs. In this case, the aircraft 2 can land like an ordinary airplane. As a result, the safety of the occupants of the aircraft 2 is increased. The aircraft 2 described thus combines the advantages of an aircraft taking off and landing vertically and those of a normal aircraft, since it can use the wings 34 as required.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• WO 2020/141513 A2 [0011]
• DE 102015001704 B5 [0012]

Claims (10)

Aircraft (2), comprising a fuselage (6) and at least two main rotors (8, 10) attached peripherally thereto, which enable the aircraft (2) to take off and land vertically, characterized by two wings ( 34). Aircraft (2) to claim 1 , wherein the respective wing (34) has at least one joint (40) on which a part (44) of the respective wing (34) can be folded up. Aircraft (2) to claim 2 , wherein on each wing (34) in each case an electric motor for folding up a part of the wing (34) is provided. Aircraft (2) according to one of the preceding claims, wherein the respective wing (34) is designed in shape such that it does not overlap with the respective adjacent rotor (8, 10) in a plan view. Aircraft (2) according to one of the preceding claims, wherein the respective wing (34) is arranged under the respective adjacent rotor (8, 10) in a vertical direction (32) of the fuselage (6). Aircraft (2) according to one of the preceding claims, wherein the respective wing (34) has at least one aileron and/or at least one take-off and loading flap (70). Aircraft (2) to claim 6 , wherein the respective wing (34) has exactly two takeoff and landing flaps (70). Aircraft (2) according to one of the preceding claims, wherein the respective wing (34) has a winglet (50). Method for operating an aircraft (2). claim 2 or 3 , wherein the wings (34) are folded in to start the aircraft (2), and the wings (34) are moved into a fully unfolded position after the aircraft (2) has taken off. procedure after claim 9 , wherein the wings (34) are folded up before landing.

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