AIRCRAFT AND METHOD FOR OPERATING AN AIRCRAFT

Abstract

The invention relates to an aircraft (1). Said aircraft (1) is characterized by a wing (2) which, viewed in section, is delimited on one side by a first profiled surface (4), which is at the bottom when the aircraft (1) is operated as intended, and on the other side by an upper second profiled surface (5), which merges at an aerofoil transition point (6) with the first profiled surface (4), wherein the first profiled surface (4) surrounds at least one air inlet opening (7), and the second profiled surface (5) surrounds at least one air outlet opening (8), and the aircraft (1) comprises a drive apparatus (12) with an air delivery apparatus (1), which is provided and designed for sucking air through the at least one air inlet opening (7) and for discharging the intake air through the at least one air outlet opening (8), wherein the at least one air outlet opening (8) is overlapped at least in part by a deflecting element (15) which, together with the second profiled surface (5), delimits an air outlet gap (16) which is flow-connected to the air outlet opening (8). The invention also relates to a method for operating an aircraft (1).

Claims

1. An aircraft (1), comprising a wing (2) which, viewed in section, is delimited on one side by a lower first profiled surface (4) when the aircraft (1) is operated as intended, and on the other side is delimited by an upper second profiled surface (5), which merges at an aerofoil transition point (6) with the first profiled surface (4), wherein the first profiled surface (4) encloses at least one air inlet opening (7) and the second profiled surface (5) has at least one air outlet opening (8) and the aircraft (1) has a drive apparatus (12) with an air delivery apparatus (1) which is provided and designed for sucking air through the at least one air inlet opening (7) and for discharging the sucked air through the at least one air outlet opening (8), wherein the at least one air outlet opening (8) is overlapped at least in part by a deflecting element (15) which, together with the second profiled surface (5) delimits an air outlet gap (16) which is flow-connected to the air outlet opening (8).

2. The aircraft according to claim 1, characterized in that the at least one air inlet opening (7) is arranged centrally in the first profiled surface (4) and/or the at least one air outlet opening (8) is arranged centrally in the second profiled surface (5).

3. The aircraft according to claim 1, characterized in that the wing (2) is ring-shaped with respect to a central longitudinal axis (3) and the profiled surfaces (4, 5) are spaced apart from one another in the axial direction at least in part.

4. The aircraft according to claim 1, characterized in that the at least one air inlet opening (7) and the at least one air outlet opening (8) are flow-connected via a flow channel (9) formed centrally in section in the wing (2), wherein in the flow channel (9) a ducted propeller (10) of the air delivery apparatus (11) is arranged to be rotatable about an axis of rotation.

5. The aircraft according to claim 1, characterized in that the air outlet opening (8) is flow-connected to the air outlet gap (16) via a connecting channel (17) which, viewed in section, is between the second profiled surface (5) and the deflecting element (15).

6. The aircraft according to claim 1, characterized in that the connecting channel (17) has a cross-section that increases or decreases in the direction of the air outlet gap (16), so that it is designed in the manner of a nozzle.

7. The aircraft according to claim 1, characterized in that the second profiled surface (5) has a first region starting from the aerofoil transition point (6) and a second region adjoining the first region and delimiting the air outlet gap (16), wherein—viewed in section—the first region is curved and the second region is curved or flat.

8. The aircraft according to claim 1, characterized in that the first profiled surface (4), viewed in section, is set back in some regions with respect to the wing transition point (6) in the direction of the second profiled surface (5), so that a vortex chamber (26) is formed which is encompassed by the aerofoil transition point (6).

9. The aircraft according to claim 1, characterized in that the first profiled surface (4) and the second profiled surface (5) in section are at least partially curved in the same direction.

10. The aircraft according to claim 1, characterized in that the second profiled surface (5) at the aerofoil transition point (6) merges into the first profiled surface (4) at an angle which with respect to a straight line (27) perpendicular to an imaginary plane continuously receiving the aerofoil transition point (6) is at least 0° and at most 60°.

11. The aircraft according to claim 1, characterized in that the deflecting element (15) can be displaced for the global and/or local change in a flow cross-sectional area of the air outlet gap (16).

12. The aircraft according to claim 1, characterized in that first control elements (18) and/or second control elements, each having a control fin (19), extend from the first profiled surface (4) and/or from the second profiled surface (5).

13. The aircraft according to claim 1, characterized in that the first control elements (18) and/or the second control elements are drive-coupled to a control drive of the aircraft (1) via a common coupling element (20).

14. A method for operating an aircraft (1), in particular an aircraft (1) according to claim 1, characterized in that the aircraft (1) comprises a wing (2) which, viewed in section, is delimited on one side by a lower first profiled surface (4) when the aircraft (1) is operated as intended, and on the other side by an upper second profiled surface (5) which is delimited merges at an aerofoil transition point (6) with the first profiled surface (4), wherein the first profiled surface (4) surrounds at least one air inlet opening (7) and the second profiled surface (5) surrounds at least one air outlet opening (8) and the aircraft (1) comprises a drive apparatus (12) with an air delivery apparatus (11), which is used to suck air through the at least one air inlet opening (7) and to discharge the intake air through the at least one air outlet opening (8), wherein the at least one air outlet opening (8) is overlapped at least in part by a deflecting element (15) which, with the second profiled surface (5), delimits an air outlet gap (16) in flow connection with the air outlet opening (8), so that the air is discharged parallel to the second profiled surface (5).

15. The method according to claim 14, characterized in that by means of the drive apparatus (12), air is sucked in in the form of an intake air stream (21) in a suction direction through the air inlet opening (7) and discharged through the air outlet gap (16) in an exit direction angled with respect to the suction direction such that at the aerofoil transition point (6) the air forms a free jet air flow (23) in a free jet direction, so that a support vortex (24) is formed between the intake air flow (21) and the free jet air flow (23), which is at least partially under the first profiled surface (4).

Description

[0049] The invention is explained in more detail below with reference to the embodiments shown in the drawing, without restricting the invention. This shows:

[0050] FIG. 1 is a schematic representation of a first embodiment of an aircraft in longitudinal section with respect to a longitudinal center axis,

[0051] FIG. 2 is a simplified schematic representation of the aircraft in a second embodiment, and

[0052] FIG. 3 is a schematic representation of the aircraft in a third embodiment.

[0053] FIG. 1 shows a schematic representation of an aircraft 1 in a first embodiment, which has at least one wing 2 which is round or ring-shaped in cross-section with respect to a longitudinal center axis 3 of the wing 2. The support surface 2 is delimited in the axial direction with respect to the longitudinal center axis 3 in a first direction by a first profiled surface 4 and in a second direction by a second profiled surface 5. Each of the profiled surfaces 4 and 5 is itself ring-shaped. The two profiled surfaces 4 and 5 merge at an aerofoil transition point 6, wherein the transition between the profiled surfaces 4 and 5 preferably is discontinuous at this point when viewed in section. The profiled surfaces 4 and 5 therefore preferably jointly form an edge at the aerofoil transition point 6. For this purpose, the aerofoil transition point 6 is in the form of a geometric circle, into which the first profiled surface 4 opens at a first angle and the second profiled surface 5 opens at a second angle different from the first angle.

[0054] The first profiled surface 4 surrounds an air inlet opening 7 and the second profiled surface 5 an air outlet opening 8. The air inlet opening 7 and the air outlet opening 8 are flow-connected to one another via a flow channel 9, wherein a ducted propeller 10 of an air delivery apparatus 11 is rotatably mounted in the flow channel 9. The air delivery apparatus 11 is part of a drive apparatus 12 of the aircraft 1. It can be clearly seen that the first profiled surface 4 is present on a side of the aircraft 1 facing a floor 13, whereas the second profiled surface 5 faces away from the ground 13. The aircraft 1 is shown here during normal and intended flight operation.

[0055] The air inlet opening 7 and the air outlet opening 8 are located centrally with respect to the longitudinal center axis 3 and are surrounded by the first profile surface 4 and the second profile surface 5, respectively, on an inner side 14 of the wing in the radial direction. The flow channel 9, which fluidically connects the air inlet opening 7 and the air outlet opening 8, is, for example, in the form of a cylinder, in particular a circular cylinder and particularly preferably in the form of a straight circular cylinder. The air inlet opening 7 and the air outlet opening 8 particularly preferably have the same flow cross-section. The air inlet opening 7 is arranged on an underside and the air outlet opening 8 on an upper side of the aircraft 1. The air outlet opening 8 is overlapped at least in part, completely in the embodiment shown here, by a deflecting element 15 which, together with the second profiled surface 5, delimits an air outlet gap 16. The air outlet gap 16 is therefore between the deflecting element 15 and the second profiled surface 5 when viewed in longitudinal section.

[0056] The air outlet gap 16 is flow-connected to the air outlet opening 8 via a connection channel 17, wherein the connection channel 17 also is at least partially delimited by the deflecting element 15 and the second profiled surface 5. In the embodiment shown here, both the air outlet gap 16 and the connecting channel 17 are formed continuously in the circumferential direction with respect to the longitudinal center axis 3 and each completely encompass the longitudinal center axis 3. According to the illustrated embodiment, a flow cross-section of the connecting channel 17 is reduced in the direction of the air outlet gap 16, so that the connecting channel 17 is in the form of a nozzle and the air outlet gap 16 represents an orifice of this nozzle.

[0057] The deflecting element 15 can be displaced in such a way that a flow cross-sectional area of the air outlet gap 16 can be changed locally and/or globally. For this purpose, the deflecting element 15 is coupled in terms of drive technology, for example, to a control drive, not shown here, of the aircraft 1. Additionally or alternatively, several first control elements 18 are connected to the control drive in terms of drive technology. In addition or as an alternative to the first control elements 18, second control elements (not shown here) can be present. The first control elements 18 are based on the first profiled surface 4; the second control elements from the second profiled surface 5. The control elements 18 each have a control fin 19 and are each drive-connected via a lever arm, not shown here, and a ball joint, also not shown, with a coupling element 20, which is present, for example, as a control ring. The coupling element 20 is used for the drive connection of the control elements 18 to the control drive, in particular to several actuating drives of the control drive, which are not shown here.

[0058] During flight operation of the aircraft 1, the drive device 12 is operated in such a way that air is conveyed from the underside of the aircraft 1 in the direction of its upper side or in such a way that air is sucked in the form of an intake air stream 21 in an intake direction through the air inlet opening 7 and is delivered through the flow channel 9 in the direction of the air outlet opening 8. The delivered air is discharged through the air outlet opening 8 and fed through the connecting channel 17 to the air outlet gap 16. The air is discharged through the air outlet gap 16 in an outlet direction in the form of an air film 22 in such a way that the air film 22 rests against the second profile surface 5. For this purpose, the air film 22 is preferably applied to the air outlet gap 16 parallel to the second profiled surface 5.

[0059] Due to the Coanda effect, the air film 22 runs along the second profiled surface 5 up to the aerofoil transition point 6. There the air film 22 detaches from the wing 2 and flows as a free jet air stream 23 in turn onto the underside of the aircraft 1, namely in a free jet direction. Here, the free jet air flow 23 stimulates a support vortex 24 which provides at least part of the lift for the aircraft 1. The support vortex 24 is reinforced by the intake air flow 21. It can be seen that both the free jet air flow 23 and the intake air flow 21 are each tangential to the support vortex 24. Due to the annular shape of the wing 2, the support vortex 24 formed has a toroidal shape. For the sake of clarity, the support vortex 24 is shown only on one side of the wing 2. Of course, however, the support vortex 24 preferably completely and continuously surrounds the longitudinal center axis 3 in the circumferential direction. Due to the high speed of the air film 22, it causes a suction effect on the surrounding air. This means that further air is supplied to the air film 22 as it flows over the second profiled surface 5. This is indicated by the arrows 25.

[0060] In order to achieve precise positioning of the support vortex 24 below the wing 2, a vortex chamber 26 is formed on the wing 2, which is delimited in the radial direction outward by the aerofoil transition point 6. The vortex chamber 26 is formed, for example, by a curvature or a recess of the first profiled surface 4. In order to achieve a particularly advantageous flow around the second profile surface 5 through the air film 22, the second profiled surface 5 merges at the aerofoil transition point 6 at an angle α into the first profile surface 4, which is determined with respect to a straight line 27 which parallel to the longitudinal center axis 3 runs through the aerofoil transition point 6. The straight line 27 is in particular perpendicular to an imaginary straight line which continuously receives the aerofoil transition point 6.

[0061] It should be pointed out that the configuration of the wing 2 described here as an annular wing 2 merely represents an advantageous embodiment. The wing 2 can also be basically straight and in this case have, for example, the cross-section shown. The advantages described can in principle also be achieved with such a configuration.

[0062] FIG. 2 shows schematically and in a simplified manner a second embodiment of the aircraft 1, wherein some elements are being shown for reasons of clarity. In principle, the second embodiment corresponds to the first embodiment, so that reference is made to the corresponding statements and only the differences are discussed below. On the one hand, these are due to the fact that the angle α is negative or greater than 180°. For example, the angle α is at least 270° and is less than 360°. Alternatively, it is at least 300° and at most 345° or at most 330°. This means that the second profiled surface 5 approaches the longitudinal center axis 3 again, starting from an outer side of the wing, on which it is at the greatest distance from the longitudinal center axis 3, before it merges into the first profiled surface 4 at the aerofoil transition point 6.

[0063] Another difference is that the air inlet opening 7 is clearly spaced in the axial direction with respect to the longitudinal center axis 3 from an imaginary plane which continuously accommodates the aerofoil transition point 6. For example, the distance is at least 20%, at least 30%, at least 40% or at least 50% of an axial distance between the plane and a point of the second profiled surface 5 or the air outlet opening that is furthest from the plane when viewed in the axial direction. As a result, the air inlet opening 7 is arranged away from the plane by the corresponding distance, so that the formation of the support vortex is facilitated.

[0064] Another difference can be seen in the fact that the second profile surface 5 is not continuously curved, but rather is composed of a first region 28 and a second region 29. The first region 28, seen in section, extends starting from the aerofoil transition point 6 to directly to the second region 29. It is preferably continuously curved when viewed in section. The second region 29, however, is planar when viewed in section or has a different curvature from the first region 28. For example, the transition between the first region 28 and the second region 29 is discontinuous when viewed in section. Alternatively, however, it can also be designed continuously.

[0065] It should be noted that each of the differences mentioned is applicable to the first embodiment. It is therefore not necessary that the differences always occur in combination with one another.

[0066] FIG. 3 shows a schematic representation of the fluid body 1 in a third embodiment. Basically, reference is again made to the above statements and only the difference from the first embodiment and the second embodiment is discussed below. The difference lies essentially in the fact that the deflecting element 15 completely overlaps the wing 2 when viewed in section, so that, starting from the longitudinal center axis 3 of the wing 2, it extends in the radial direction to beyond the outer side of the wing. The air inlet opening 7 and the air outlet opening 8 are preferably located in imaginary planes which are spaced apart parallel to one another and are perpendicular to the longitudinal center axis 3 and bear against the wing 2 from opposite sides. The plane in which the air inlet opening 7 is present is arranged on an underside and the plane in which the air outlet opening 8 is present on an upper side of the wing 2.

[0067] The air outlet gap 16 is in the form of an annular gap and is completely accommodated in an imaginary plane that is perpendicular to the longitudinal center axis 3. This imaginary plane is preferably located between the planes of the air inlet opening 7 and the air outlet opening 8, in particular closer to the former. However, it can also be present on the side of the air inlet opening facing away from the air outlet opening 8. The embodiment described enables particularly effective guidance of the air from the outlet opening 8 to the air outlet gap 16, in particular without utilizing the Coanda effect. The connecting channel 17, which fluidically connects the air outlet opening 8 and the air outlet gap 16, has, viewed in section, a flow cross-section that is continuously decreasing at least in sections, in particular continuously, wherein the flow cross-section in the air outlet gap 16 is smaller than at the air outlet opening 8. It can be provided, purely optionally, that the deflecting element 15 has a plurality of air guide webs. The air guide webs start from a base body of the deflecting element 15 and protrude into the connecting channel 17. The air guide webs extend in the radial direction and are preferably evenly distributed in the circumferential direction with respect to the longitudinal center axis 3. The air guide webs serve to guide the air entering the connecting channel 17 from the air outlet opening 8. They reduce a swirl in the air which it possibly has due to the air delivery apparatus 11, not shown here. In addition, in the embodiment shown here, the air delivery apparatus 11 is preferably fastened to the deflecting element 15 and, in particular, is only fastened to the supporting surface 2 via this.

[0068] The control of the aircraft 1 also takes place in the third embodiment preferably with the first control elements 18 and/or the second control elements, not shown here. The first control elements 18 and the second control elements can be configured in accordance with the above explanations. In the case of the second control elements, a mounting can be implemented particularly preferably on both the wing 2 and on the deflecting element 15. The second control elements are therefore rotatably mounted on the one hand on the wing 2 and on the other hand on the deflecting element 15. Alternatively, however, a mounting can also only take place on the wing 2 or the deflecting element 15, so that the control element or a shaft used for bearing the control element is spaced apart from the deflecting element 15 or the wing 2.

[0069] It can also be provided, purely optionally, that, in comparison to the first embodiment, the first control elements 18 and/or the second control elements are omitted. The aircraft 1 is controlled, for example, by displacing and/or deforming control elements which form part of the wing 2 and start from a base body of the wing 2. The control elements are arranged and/or articulated to the base body on a side of the base body lying on the outside in the radial direction. By displacing and/or rotating the control elements with respect to the base body, the air exiting through the air outlet gap 16 can be deflected and thus the aircraft 1 can be controlled. The control elements can preferably be displaced and/or rotated independently of one another. However, they can also be coupled to one another so that the displacement and/or rotation takes place, for example, by means of a common actuator.

[0070] It should be pointed out that the explanations relating to the third embodiment can also be used for the first embodiment and the second embodiment. It can therefore also be provided, for example, that according to the difference described, the deflecting element 15 completely overlaps the wing 2, but instead of the control elements, the optional control elements of the third embodiment are present. The deflecting elements can of course also be present, but the deflecting element 15 only partially overlaps the wing 2. To this extent, the deflecting elements can also be used in the context of the first embodiment or the second embodiment.

[0071] The aircraft 1 described has the advantage in all embodiments that it works extremely energy-efficiently due to the use of the support vortex 24 to provide at least part of the lift. In addition, the aircraft 1 can be controlled extremely precisely by means of the displaceable deflecting element 15 and/or the control elements 18. In particular, the aircraft 1 can hover in the air analogously to a helicopter. Nevertheless, it can achieve very high speeds because, in contrast to the helicopter, it is not limited by a maximum flow speed at the blade tips of a rotor.