Engine for a missile, method for operating an engine for a missile, and missile with at least one engine

Description

[0001] The invention relates to an engine for a missile according to claim 1. The invention further relates to a method for operating an engine for a missile according to claim 13 and a

[0002] Missile having at least one engine according to claim 14.

[0003] For example, the prior art document DE 20 2018 104 722 U1 is known. This document describes an aircraft with a frame structure and several lifting rotors arranged on the frame structure, by means of which a vertically upwardly directed primary lift and propulsive forces can be generated. In addition, a jet turbine is provided, the thrust jet of which can be aligned such that a secondary lift directed essentially parallel to the primary lift can be generated, which can be superimposed on the primary lift. Furthermore, the document US 5,203,521 shows an aircraft with an annular body defining a central passage, with an upper deflector, with a lower collector, and with a fluid drive in the passage. Air is accelerated by means of a drive and circulated around the annular body.The collector divides the circulating air, directing part of the air into the passage and part of the air beneath the aircraft to provide thrust. Further aircraft are known from US Pat. Nos. 3,747,726 and 2,997,254. US Pat. No. 3,215,218 also shows a vehicle device for increasing traction.

[0004] US 3 397 853 defines an annular hull defined by a hollow annular frame, the upper inclined outer surface portion of which is capable of receiving a controlled amount of a laminated liquid film to guide the vehicle movement in a predetermined manner.

[0005] The object of the invention is to propose an engine which has advantages over known engines, in particular with regard to the thrust it provides, is widely scalable and also enables particularly efficient operation.

[0006] This is achieved according to the invention with an engine for a missile having the features of claim 1. It is provided that the vortex guide element is present as a rotary body which is formed by rotation of a closed curve having a continuous course at least on its radially outer side around a rotation axis, and that the air inlet opening opens directly into an external environment of the engine, so that when the engine is operated as intended, air is conveyed from the side of the engine facing away from the air deflection element through the air inlet opening into the intake duct.

[0007] The engine is designed and constructed to power the missile. It can therefore also be referred to as an aviation engine. Of course, the engine can also be separate from the missile. The missile powered or propellable by the engine can, in principle, take any form; for example, it can be an unnamed aircraft, such as a drone, or—preferably—an aircraft. An aircraft is a vehicle that flies within the Earth's atmosphere. It represents a mobile means of transport used to transport people, goods, or the like. The aircraft is therefore designed and constructed for passenger transport and / or freight transport.

[0008] The aircraft is preferably heavier than air and has a propulsion system or a power drive, so that the aircraft as a whole can be referred to as an aircraft. Generally speaking, an aircraft is a vehicle that is heavier than air and generates the dynamic lift necessary for its flight using non-rotating lifting surfaces. The aircraft, in particular the engine, can also be lighter than air overall. For this purpose, the aircraft or the engine, for example, has lift-generating means.

[0009] The flying object can, of course, also have a different design, for example, it can be in the form of an airworthy motor vehicle. Such a motor vehicle is, for example, intended and designed to be moved at least temporarily on the ground or in contact with the ground, in particular on the wheels of the motor vehicle, and to fly temporarily at a distance from the ground, namely powered by the engine. The engine is thus used to propel the motor vehicle, at least during flight operation. However, it can also be used to generate propulsion while the motor vehicle rests on its wheels on the ground.

[0010] The engine has the vortex guide element and the air deflection element as essential elements. The vortex guide element and the air deflection element work together to generate thrust, which serves to propel the missile and is directed in a specific direction. Preferably, the thrust of the engine is aligned, at least temporarily, in such a way that it creates lift for the missile. For this purpose, the thrust is usually directed geodetically downwards, i.e. emanating from the missile towards a subsurface or ground. It should be emphasized at this point as being particularly important that the engine extracts or draws in air from the environment from the same side of the engine on which the thrust or a thrust jet generated by the engine is subsequently present.In other words, when the engine is operating as intended, the air is preferably sucked in from geodetically below the engine or the missile.

[0011] The vortex guide element is generally ring-shaped and completely and continuously encompasses the longitudinal center axis of the engine in the circumferential direction. A longitudinal center axis of the vortex guide element preferably corresponds to the longitudinal center axis of the engine. For example, the vortex guide element is rotationally symmetrical with respect to an axis of symmetry. In this case, the axis of symmetry preferably coincides with the longitudinal center axis of the engine. The above-mentioned section is to be understood in particular as a longitudinal section with respect to the longitudinal center axis of the vortex guide element or with respect to the longitudinal center axis of the engine. The thrust provided by the engine is preferably parallel to the longitudinal center axis of the engine and / or the longitudinal center axis of the vortex guide element. In other words, a thrust vector of the engine is parallel to one of the aforementioned longitudinal center axes.This applies at least in at least one position of the vortex guide element and the air deflection element relative to each other, if these can be displaced relative to each other.

[0012] The vortex guide element preferably has a continuous outer circumference when viewed in section or half-section. This means that - again in section, in particular in longitudinal section with respect to the longitudinal center axis of the vortex guide element - the outer circumference of the vortex guide element has no discontinuities or jumps, but runs evenly. For example, the vortex guide element is oval, in particular circular or elliptical, when viewed in half-section. A half-section is understood to be a section through a sectional plane in which only one side of a further plane perpendicular to the sectional plane is considered. For example, both the sectional plane and the further plane include the longitudinal center axis of the vortex guide element. In other words, only one half of the actual section is used in the half-section.

[0013] It is intended that the vortex guide element is in the form of a rotating body. A rotating body is understood to be a body formed by rotating a closed curve around a rotation axis or figure axis. The rotation axis corresponds to the longitudinal center axis of the vortex guide element. It preferably coincides with the longitudinal center axis of the engine and / or a longitudinal center axis of the missile. In at least one position of the vortex guide element and air deflection element, it can also coincide with the longitudinal center axis of the air deflection element. The curve is particularly preferably continuously spaced from the rotation axis in order to form the intake duct, which is then centrally located with respect to the rotation axis. The curve has a continuous profile, at least on its side lying radially outward with respect to the rotation axis.This means that there are no edges, especially no marginal edges, on the radially outer side of the vortex guide element, but rather that discontinuities are avoided. This results in particularly low flow losses.

[0014] For example, the continuous course of the curve extends in the radial direction inwards, in particular as seen in a section or half-section through the engine, over at least 10%, at least 15%, at least 20% or at least 25% of the extension of the curve in the radial direction, starting from an outermost point of the curve in the radial direction. The curve runs radially inwards on both sides of the outermost point, so that a first profile surface and a second profile surface of the vortex guide element are formed, which delimit the vortex guide element in the axial direction on opposite sides. On both sides of the outermost point, the curve runs continuously in the radial direction, namely in each case over one of the aforementioned portions of the curve. Particularly preferably, the curve has two regions which lie on opposite sides of an imaginary plane which lies parallel to the axis of rotation and intersects the curve.

[0015] A first of the regions lies on the outside in the radial direction and a second of the regions lies on the inside in the radial direction. Relative to a distance in the radial direction between the outermost point in the radial direction and an innermost point of the curve in the radial direction, the plane is, for example, at least 10%, at least 20%, at least 30%, at least 40% or at least 50% away from the outermost point. However, it is particularly preferably at least 60%, at least 70%, at least 80% or at least 90% away from it. Values ​​of at least 80% and more are particularly preferred. In the first region, the curve is continuously continuous. In the second region, it can also be continuous or, alternatively, be discontinuous at least in some regions. Particularly preferably, the first region directly borders on at least one discontinuity, in particular directly on several discontinuities, of the curve that are present in the second region.However, it can also be provided that the curve has a region on its radially inner side with respect to the axis of rotation in which it is discontinuous. Aside from this region, which can also be referred to as the discontinuity region, the curve is continuous. For example, in the discontinuity region the curve has a straight section from which the curve emanates on at least one side, forming a point of discontinuity. The straight section extends, for example, between the air inlet opening and the air outlet opening and to this extent delimits the intake duct in the radially outward direction. Preferably, the straight section extends from the air inlet opening to the air outlet opening.

[0016] For example, it is intended that the vortex guide element, viewed in half-section in the axial direction, has dimensions that correspond to at least 25% or at least 50% of its dimensions in the radial direction. Alternatively, the dimensions in the axial direction can also be larger and correspond to at least 75% or at least 100% of the dimensions in the radial direction. The dimensions of an area enclosed by the curve described above in the axial direction therefore correspond to at least one of the aforementioned proportions of its dimensions in the radial direction.

[0017] The vortex guide element is penetrated by the intake duct, which is preferably arranged centrally in the vortex guide element, i.e. is coaxial with the vortex guide element. The intake duct is particularly preferably straight throughout. The intake duct extends from the air inlet opening to the air outlet opening. The air conveying device is arranged in the intake duct and serves to convey the air through the intake duct from the direction of the air inlet opening towards the air outlet opening. The air conveying device can be driven, for example, by means of a drive device. The drive device is, for example, in the form of an electric motor, a turbine or an internal combustion engine, or at least has such a device. The air conveying device is, for example, a propeller, which can also be referred to as an impeller due to its arrangement in the intake duct, since it is surrounded by the vortex guide element.Other designs of the air conveying device are also fundamentally feasible, as long as they can be used to convey the air through the intake duct.

[0018] The air inlet opening is preferably understood to be an opening that is continuously delimited by the vortex guide element in the circumferential direction with respect to the longitudinal center axis of the vortex guide element and that lies continuously in an imaginary plane. The imaginary plane continuously intersects the vortex guide element in the circumferential direction or at least lies tangentially thereto. Particularly preferably, the imaginary plane lies tangentially thereto in the circumferential direction. The imaginary plane is, for example, perpendicular to the longitudinal center axis of the vortex guide element. The same applies analogously to the air outlet opening. The air release opening is therefore also continuously delimited by the vortex guide element in the circumferential direction.Preferably, it also lies continuously in a (further) imaginary plane that continuously intersects the vortex guide element in the circumferential direction or is tangentially adjacent to it, particularly preferably tangentially adjacent to the vortex guide element in the circumferential direction. This imaginary plane can also be perpendicular to the longitudinal center axis of the vortex guide element.

[0019] In addition to the vortex guide element, the engine also has an air deflection element. During normal operation of the engine or missile, the air deflection element is arranged geodetically above the vortex guide element, at least partially, in particular largely or completely. In other words, a side of the vortex guide element facing the air deflection element is arranged geodetically above a side of the vortex guide element facing away from the air deflection element. From a geodetic perspective, the vortex guide element is therefore located between the air deflection element and the ground during normal operation. A different geodetic alignment of the air deflection element and the vortex guide element can also be provided in principle. However, it is essential that the air is sucked in through the air inlet opening in a different direction than that expelled through the air outlet gap.

[0020] In particular, the axial velocity components of a respective velocity vector differ from one another in terms of their sign, given the same reference system. Thus, if the axial velocity component of one of the velocity vectors is less than zero, the axial velocity component of another of the velocity vectors is at least zero, in particular exactly zero or greater than zero, or vice versa. The basic design is to draw in air directly from the outside environment through the air inlet opening and expel it directly into the outside environment through the air outlet gap. The air therefore flows into the engine, in particular into the missile, through the air inlet opening and out of the engine, in particular out of the missile, through the air outlet gap.

[0021] It is preferably provided that the air inlet opening and the air outlet gap are aligned such that, during normal operation of the engine, the air flows in through the air inlet opening in a direction which is axially opposite to or perpendicular to a direction through which air exits from the air outlet gap. The air from the outside environment enters the intake duct through the air inlet opening in a first direction or with a first velocity vector. In contrast, it exits the air outlet gap in a second direction or with a second velocity vector from the radial duct. The first direction and the second direction are, for example, perpendicular to one another or axially opposite to the longitudinal center axis of the engine.For example, it can be provided that the first velocity vector has only an axial velocity component and the second velocity vector only a radial velocity component, whereas the other velocity components are zero. If both the first velocity vector and the second velocity vector each have an axial velocity component, they are opposite to each other. Thus, with the same reference system, one of the velocity components is positive and the other negative.

[0022] The air deflection element overlaps the vortex guide element at least in part. It is arranged on the side of the vortex guide element having the air outlet opening. Preferably, a longitudinal center axis of the air deflection element is arranged at least temporarily parallel to the longitudinal center axis of the vortex guide element and / or the longitudinal center axis of the engine. Preferably, the longitudinal center axis of the air deflection element corresponds to one of the aforementioned longitudinal center axes, in particular in at least one position of the vortex guide element and the air deflection element relative to one another. In other words, the air deflection element is advantageously arranged coaxially to the vortex guide element.

[0023] The air deflection element extends radially outwards, in particular starting from its longitudinal center axis and / or the longitudinal center axis of the engine, wherein it completely overlaps the air outlet opening in the radial direction. The air deflection element has larger dimensions in the radial direction than the air outlet opening, so that in cross-section the air deflection element projects further outwards in the radial direction than the air outlet opening. Away from the air outlet opening, namely radially outwards from the air outlet opening, the air deflection element delimits the air outlet gap together with the vortex guide element. The air outlet gap is fluidically connected to the air outlet opening via a radial duct which is also jointly delimited by the vortex guide element and the air deflection element. The radial duct thus extends fluidically from the air outlet opening to the air outlet gap.

[0024] During engine operation, the air exiting the intake duct through the air outlet opening is deflected radially outward by the air deflection element, so that it flows toward the air outlet gap and subsequently enters the engine's external environment. For example, the air outlet gap is located on the same side of an imaginary plane as the air inlet opening, whereas the air outlet opening is located on the opposite side of the imaginary plane. The imaginary plane is, for example, perpendicular to the longitudinal center axis of the vortex guide element.

[0025] The air exiting the air outlet gap flows along the vortex element and subsequently contributes to generating the engine's thrust. For example, during normal engine operation, the air deflection element is positioned geodetically above the vortex guide element. In other words, the vortex guide element should be located between the air deflection element and the ground. This in turn means that the engine draws in air from geodetically below the engine or missile, i.e., ultimately - geodetically speaking - draws in air from the outside environment from the underside of the engine or missile and initially conveys it towards the top of the engine. Subsequently, at least some of the air returns to the underside to generate thrust there.

[0026] The air inlet opening is located on the side of the vortex guide element facing away from the air deflection element. To ensure effective thrust delivery, it opens directly into the engine's external environment. This means that no other element of the engine and / or missile is located between the air inlet opening and the external environment. Rather, an imaginary extension of the intake duct on the side of the air inlet opening is designed to be unobstructed and extend into the external environment. Therefore, no other element of the engine and / or missile is located in the imaginary extension. As a result, when the engine is operating as intended, air is pumped from the side of the engine facing away from the air deflection element through the air inlet opening into the intake duct.

[0027] This means that during normal operation of the engine, air is sucked in from the outside environment in the direction opposite to the engine's thrust vector. While the engine provides thrust using the thrust vector, it sucks in the air used to provide the thrust in the opposite direction, namely directly from the outside environment. As already pointed out above, the air inlet opens directly into the outside environment of the engine, so that the air is also sucked in directly from the outside environment. In other words, the air inlet is designed without any overlap, so that there is a free airspace below the air inlet in the outside environment of the engine. Free airspace is understood to be airspace that is completely filled with air and in which there is no other element of the engine and / or the missile.

[0028] The free airspace extends below the air inlet opening, in particular it starts directly from the air inlet opening. The free airspace is an imaginary extension of the intake duct, namely starting from the air inlet opening. In this case, it is provided, for example, that the airspace has an extension in the axial direction with respect to the longitudinal center axis of the engine that corresponds to at least one extension of the vortex guide element and / or one extension of the air deflection element in the same direction. The airspace thus has certain dimensions, namely at least in the axial direction. This means that, starting from the air inlet opening over at least the aforementioned extension, no further element of the engine and / or the missile is present on the side of the vortex guide element that has the air inlet opening.

[0029] Preferably, the extent of the airspace is at least 2, at least 3, at least 4, or at least 5 times greater than the extent of the vortex guide element, the extent of the air deflection element, or the joint extent of the vortex guide element and the air deflection element in the same direction. These considerations, of course, only apply during flight operation of the engine or missile. If the missile is close to the ground, the free airspace may be limited by the ground. In this case, however, there is also no other element of the engine and / or missile between the air intake opening and the ground.

[0030] Additionally or alternatively, it can be provided that an airspace delimited in the axial direction with respect to the longitudinal center axis of the engine on the one hand by the air inlet opening and on the other hand by the air conveying device and in the radially outward direction by the vortex guide element is completely filled with air. This airspace, which is part of the intake duct and is therefore delimited by the vortex guide element, is also designed as a free airspace. No other element of the engine and / or the missile is arranged in it, so that it is completely filled with air. The airspace extends in the axial direction from the air inlet opening to the air conveying device. In the radially outward direction it is delimited by the vortex guide element.

[0031] These statements make it clear that the flow around the vortex guide element is as unobstructed as possible, allowing air from the outside environment to enter the intake duct unhindered through the air inlet opening. This results in efficient engine operation. The engine and, in particular, the vortex guide element are preferably located as an outer part of the missile. They thus form an outermost element of the missile and are accordingly located on its outer surface. In other words, the engine and, in particular, the missile are delimited by the vortex guide element in the direction of the outside environment, so that the outside environment of the missile extends directly to the vortex guide element.

[0032] During engine operation, air from the outside environment is drawn through the air inlet opening into the intake duct. From there, it subsequently exits through the air outlet opening into the radial duct and flows through the radial duct to the air outlet gap. The air outlet gap surrounds the vortex guide element in a ring-like manner, preferably completely and continuously in the circumferential direction relative to the longitudinal center axis of the vortex guide element and / or the longitudinal center axis of the engine. The air exiting the air outlet gap, viewed in section, continues to flow along the vortex guide element or an outer contour of the vortex guide element, namely at least partially due to the Coanda effect.

[0033] It can be provided that the air flows, viewed in section, along the vortex guide element as far as the air inlet opening, so that at least a portion of the air exiting the air outlet gap is conveyed again through the air inlet opening into the intake duct. In any case, the engine is operated in such a way that a flow around the vortex element occurs, so that ultimately a vortex is present which surrounds the vortex guide element and which is preferably shaped like a body of revolution, in particular shaped like a rotational torus. The vortex generated by the engine, which can also be referred to as a supporting vortex, completely surrounds the vortex guide element when viewed in section. It also surrounds the vortex guide element in the circumferential direction, preferably continuously and uninterruptedly. In other words, the supporting vortex envelops the vortex guide element.

[0034] The thrust generated by the engine is achieved through different mechanisms. Firstly, the flow velocity on the side of the vortex guide element facing the air deflection element, i.e. in the radial duct, is higher than the flow velocity on the side of the vortex guide element facing away from the air deflection element, i.e. in the outside environment. Due to the different flow velocities, according to the Bernoulli equation, a negative pressure is created on the side of the vortex guide element facing the air deflection element compared to the side of the vortex guide element facing away from the air deflection element. Since the flow velocity of the air on the side facing the air deflection element is greater than the flow velocity of the air on the side facing away from the air deflection element, the pressure on the side facing the air deflection element is lower than that on the side facing the air deflection element.The pressure difference between the pressures on the opposite sides of the vortex guide element causes part of the thrust generated by the engine.

[0035] A further portion of the thrust is provided indirectly by the support vortex as soon as it is present. The support vortex conveys air from the outside environment from the side of the air deflection element facing away from the vortex guide element to the side of the vortex guide element facing away from the air deflection element. For example, part of the air is added to the support vortex and forced onto the side of the vortex guide element facing away from the air deflection element, i.e. in particular onto the side of the engine facing the ground. This provides thrust that is not caused directly by the flow of the support vortex itself, but rather by the air from the outside environment that is additionally conveyed by the support vortex. In general terms, it can be stated that the engine provides thrust on the same side from which it draws in air from the outside environment.Accordingly, a thrust jet generated by the engine is present on the side of the vortex guide element facing away from the air deflection element. The air intake opening through which the engine draws in air from the outside environment is also located on this side.

[0036] It is obvious that the lift vortex can only develop when the engine is sufficiently far from the ground. To utilize the lift generated by the lift vortex, it is therefore first necessary to separate the engine or missile from the ground. This can be achieved, for example, using a mechanical lifting device that raises the missile and thus the engine above the ground. Of course, the missile can also be launched with another engine, and only then can the engine be activated.

[0037] The use of the lift vortex to at least partially provide the engine's thrust enables particularly energy-efficient operation of the engine because the lift vortex can be generated and maintained with a comparatively low energy expenditure, which is significantly lower than the energy expenditure that would be required to directly generate the thrust. The lift vortex also results in particularly high stability of the engine and thus of the missile in the air because the lift vortex occupies a large volume of air and creates a voluminous air cushion for the engine or missile. The engine and, accordingly, the missile are almost infinitely scalable in terms of lift capacity because the lift vortex is also essentially infinitely scalable, as it is designed like a potential vortex.

[0038] A further development of the invention provides that the vortex guide element, seen in section, is delimited on the one hand by a first profile surface and on the other hand by a second profile surface, wherein the two profile surfaces merge directly and continuously into one another on both sides, in particular in an imaginary plane perpendicular to the central axis. The first profile surface and the second profile surface lie on opposite sides of an imaginary plane which intersects the vortex guide element. This imaginary plane is preferably perpendicular to the longitudinal central axis of the vortex guide element. For example, the imaginary plane passes through the vortex guide element centrally in the axial direction with respect to the longitudinal central axis, thus dividing the vortex guide element into two parts which have the same extension in the axial direction. The two parts of the vortex guide element can be designed symmetrically to one another with respect to the imaginary plane.The first profile surface is located on the side of the vortex guide element facing away from the air deflection element, and the second profile surface is located on the side of the vortex guide element facing the air deflection element. The two profile surfaces merge seamlessly into each other on each side, without discontinuities or jumps. This creates a surface of the vortex guide element over which air flows with particularly low losses, resulting in high efficiency.

[0039] Preferably, it is provided that, viewed in section, a radius of curvature of the first profile surface and / or a radius of curvature of the second profile surface each has / have the same sign throughout. The first profile surface is defined in section by a first profile line and the second profile surface by a second profile line. The profile surfaces or the profile lines each have a radius of curvature which can change over their extent or can remain constant. At least, however, it is provided that one of the radii of curvature or both radii of curvature have the same sign throughout, i.e. that the sign of the respective radius of curvature does not change over the extent of the respective profile surface but remains the same.

[0040] For example, the radius of curvature of the first profile surface, viewed in section, is selected to have the same sign over the entire extent of the first profile surface. Analogously, additionally or alternatively, the radius of curvature of the second profile surface, viewed in section, can have the same sign over the entire extent of the second profile surface. Preferably, the first profile surface and the second profile surface have radii of curvature with the same sign. Particularly preferably, the radii of curvature of the first profile surface and the second profile surface are identical, so that the vortex guide element is circular when viewed in section, in particular when viewed in half section. This results in a particularly aerodynamic design of the vortex guide element.

[0041] A further development of the invention provides that the vortex guide element is designed as a rotational body, in particular as a rotational torus. The rotational body is a body formed by rotating a closed curve around a rotational axis. For example, the curve is curved at least in some regions, in particular curved throughout. Preferably, a radius of curvature of the curve has the same sign over the entire curve. It can therefore be provided that the radius of curvature is consistently at least zero or consistently at most zero or - if the curve is continuously curved - is consistently greater than zero or consistently less than zero. The rotational torus is in turn understood to be a rotational body that is generated by rotating a circle around an axis of rotation lying in the circular plane and not intersecting the circle.The rotational axis of the rotating body is, in particular, the longitudinal center axis of the vortex guide element. The rotating body is designed to be continuous and uninterrupted in the circumferential direction with respect to its rotational axis. This enables particularly effective guidance of the supporting vortex while simultaneously minimizing fluid losses.

[0042] A further development of the invention provides that the air outlet gap is in flow connection with the air outlet opening via a radial duct, which has a flow cross-section that decreases in the direction of the air outlet gap, so that it is designed like a nozzle. The radial duct is preferably continuous in the circumferential direction with respect to the longitudinal center axis of the engine and - apart from one or more support struts, which are optionally present - uninterrupted. In the radial direction, it extends from the air outlet opening to the air outlet gap, so that the air exiting from the intake duct through the air outlet opening flows through the radial duct to the air outlet gap. The flow cross-section of the radial duct decreases in the direction of the air outlet gap.The shape of the radial duct is selected in particular so that the air in the air outlet gap has a desired flow velocity. This flow velocity is preferably in the subsonic range, so that no negative mechanical influences on the engine due to fluidic shocks or the like are to be expected. The nozzle-like design of the radial duct enables effective engine operation.

[0043] A further development of the invention provides that the air deflection element overlaps the vortex guide element in such a way that the air in the radial duct, at least partially from the air outlet opening to the air inlet opening, rests against the vortex guide element without any flow separation. It has already been pointed out that the engine is operated in such a way that the supporting vortex surrounds the vortex guide element. In order to achieve a particularly low-loss flow around the vortex guide element, separation of the flow or the supporting vortex from the vortex guide element should be avoided as far as possible, in particular completely. For this purpose, the air deflection element surrounds the vortex guide element. The extent of the overlap is selected such that the separation-free flow around the vortex guide element is achieved by the air exiting from the air outlet opening.At least a portion of the air exiting the air outlet and subsequently the air outlet gap should contact the vortex guide element in such a way that it flows back to the air inlet and is conveyed through it into the intake duct. This enables the previously discussed high efficiency of the engine, which is achieved through the low-loss generation of the support vortex.

[0044] A further development of the invention provides that the air deflection element completely overlaps the vortex guide element in the radial direction, in particular such that the air outlet gap has a surface normal that runs parallel to the longitudinal center axis of the engine, or such that the surface normal intersects the longitudinal center axis of the vortex guide element below the vortex guide element. In the radially outward direction, the air deflection element thus projects beyond the vortex guide element. The air outlet gap defined by the air deflection element and the vortex guide element is continuously intersected centrally in the circumferential direction by an imaginary plane or lies completely in this imaginary plane. The imaginary plane is perpendicular to the longitudinal center axis of the vortex guide element and / or the longitudinal center axis of the air deflection element.

[0045] The air outlet gap has a surface normal that runs, for example, parallel to the longitudinal center axis of the engine. In this case, the air outlet gap lies entirely within the imaginary plane. However, it can also be provided that the surface normal intersects the longitudinal center axis of the vortex guide element below the vortex guide element. In this case, the imaginary plane intersects the air outlet gap at a specific angle. Such extensive overlap reliably prevents the air from detaching from the vortex guide element even outside the radial duct, so that at least a portion of the air exiting through the air outlet gap flows to the air inlet opening and is conveyed through this again into the intake duct.

[0046] A further development of the invention provides that the air deflection element has a projection which engages in the intake duct and to which a drive device for driving the air conveying device is fastened. The projection extends from a base element of the air deflection element into the intake duct. For example, the base element is located outside the intake duct, so that only the projection projects into the intake duct. The projection is preferably rotationally symmetrical with respect to the longitudinal center axis of the air deflection element. Additionally or alternatively, a longitudinal center axis of the projection corresponds to the longitudinal center axis of the vortex guide element. As a result, flow resistance caused by the projection is reduced as much as possible. The drive device which serves to drive the air conveying device is fastened to the projection.

[0047] For example, the air conveying device, such as a propeller, a compressor impeller, or the like, is rotatably mounted on the projection. This results in a particularly compact design of the engine.

[0048] A further development of the invention provides that an air deflection surface of the air deflection element, which borders the radial channel and faces the vortex guide element, is continuously curved in cross-section, in particular has a radius of curvature that lies within a specific radius of curvature range. The air deflection surface extends radially from the air outlet opening outward to the air outlet gap. It borders the radial channel in the axial direction in the direction away from the vortex guide element.

[0049] In order to achieve particularly low flow losses within the radial duct, the air deflection surface is continuously curved. It has a radius of curvature which can be constant over its extension, starting from the air outlet opening up to the air outlet gap. However, it can also be provided that the radius of curvature changes over the extension of the air deflection surface in the radial direction outwards. Preferably, however, it always remains within the radius of curvature range. In particular, the radius of curvature is selected such that it changes over the entire extension of the air deflection surface in the radial direction from the inside to the outside by a maximum of 10%, a maximum of 5%, a maximum of 2.5%, or a maximum of 1%. If the radius of curvature remains constant, the air deflection surface has the shape of a partial circle when viewed in section. This enables the realization of particularly low flow losses.

[0050] A further development of the invention provides that, viewed in section, the radius of curvature of the air deflection surface is greater than a radius of curvature of an air guide surface of the vortex guide element that delimits the radial channel. Thus, viewed in section, the radial channel is delimited on the one hand by the air deflection surface of the air deflection element and on the other hand by the air guide surface of the vortex guide element. The air guide surface forms the second profile surface, at least in part. The same applies to the radius of curvature of the air guide surface as to the radius of curvature of the air deflection surface. Preferably, the radius of curvature is constant over the entire extent of the air deflection surface, namely from the air outlet opening to the air outlet gap. In this case, the radius of curvature of the air deflection surface is greater than the radius of curvature of the air guide surface.The side of the vortex guide element facing the air deflection element can also be circular in cross-section. This also serves to achieve low flow losses.

[0051] A further development of the invention provides that the radius of curvature of the air deflection surface and the radius of curvature of the air guide surface are selected such that the flow cross-section of the radial duct decreases continuously from the air outlet opening to the air outlet gap. By selecting different radii of curvature, the nozzle-like shape of the radial duct is realized in a structurally simple manner.

[0052] A further development of the invention provides that the vortex guide element is displaceable relative to the air deflection element for globally and / or locally changing a flow cross-section of the air outlet gap, in particular for adjusting a thrust vector of the engine. The air deflection element is therefore displaceable relative to the vortex guide element, in particular by means of a control drive, in such a way that the size of the air outlet gap is changed, namely either globally and / or locally in the circumferential direction. The global change of the air outlet gap or the flow cross-sectional area of ​​the air outlet gap is to be understood as meaning that the size of the air outlet gap or the flow cross-sectional area is changed uniformly over the entire extent of the air outlet gap, i.e., is increased or decreased.Local modification, on the other hand, involves a merely localized enlargement or reduction of the air outlet gap or the flow cross-sectional area. For example, to achieve local modification, the air deflection element is relocated in such a way that the air outlet gap is enlarged or reduced in certain areas. By changing the flow cross-sectional area of ​​the air outlet gap, the thrust vector can be easily controlled.

[0053] A further development of the invention provides that, in order to globally change the flow cross-sectional area of ​​the air outlet gap, the distance between the air deflection element and the vortex guide element can be uniformly varied. Uniform variation is understood to mean a uniform enlargement or reduction of the air outlet gap. For example, the air deflection element is displaced parallel to the longitudinal center axis of the vortex guide element, namely away from the vortex guide element to enlarge the air outlet area and toward the vortex guide element to reduce the flow cross-sectional area. This enables particularly effective control of the thrust vector by adjusting the vortex intensity of the supporting vortex.

[0054] A further development of the invention provides that the air deflection element can be tilted relative to the vortex guide element in order to locally change the flow cross-sectional area of ​​the air outlet gap. By tilting the air deflection element, the air outlet gap is locally changed, in particular partially enlarged and partially reduced. The tilting occurs, for example, relative to the longitudinal center axis of the vortex guide element. Preferably, the air deflection element is designed such that, with a parallel alignment of the air deflection element with respect to the longitudinal center axis of the vortex guide element and thus at an angle of 0°, the air outlet gap has a consistently constant size in the circumferential direction with respect to the longitudinal center axis. When the angle is changed, however, a local change in the flow cross-sectional area occurs. Such a design again enables particularly efficient control of the thrust vector.

[0055] A further development of the invention provides for control elements, each having a control fin, to be rotatably mounted in the radial channel. The control elements serve to adjust the thrust vector of the engine, namely by influencing the direction in which the air exits the air outlet gap. Each of the control elements has a control fin, which is designed, for example, as a plate-like or wing-like structure. In the latter case, the control fin can be symmetrical with respect to its profile chord or have a flow-oriented profile. The control elements enable, for example, the generation of thrust in the circumferential direction, so that the engine or the missile propelled by it can rotate on the spot around its longitudinal center axis.

[0056] A further development of the invention provides that the control elements are drive-coupled to a control drive of the engine via a common coupling element. The control drive serves to adjust the control elements. It is only indirectly connected to the control elements via the common coupling element. For this purpose, the control elements, on the one hand, and the control drive, on the other, engage the coupling element. In particular, the control drive engages the coupling drive at a distance from the control elements. This enables simultaneous adjustment of the control elements by means of the control drive. The air deflection element can also be connected additionally or alternatively to the coupling element.

[0057] A further development of the invention provides that the coupling element is coupled to the control elements and / or the control drive via a ball joint and a lever arm. Each control element and / or the control drive is assigned a ball element and a lever arm, by means of which they are connected to the control drive. The use of the ball joint ensures extremely flexible adjustment of the control elements via the control drive.

[0058] A further development of the invention provides that the coupling element is designed as a control ring. The control ring preferably encompasses the longitudinal center axis of the engine continuously and completely in the circumferential direction. It engages the control elements to couple them to the control drive. The control ring is arranged such that it can not only describe a rotational movement in the circumferential direction with respect to the longitudinal center axis, but that it is also tiltable and thus acts like a swashplate. This enables the aforementioned flexible actuation of the control elements by means of the control drive.

[0059] A further development of the invention provides that the control drive comprises a plurality of actuators, each of which is drive-coupled to the coupling element at a distance from one another. Preferably, the actuators are evenly spaced from one another, so that in the case of two actuators, they engage the coupling element at a distance of 180°, in the case of three actuators at a distance of 120°, and in the case of four actuators at a distance of 90°. The use of the plurality of actuators enables displacement of the coupling element not only in the circumferential direction relative to the longitudinal center axis, but also in the radial direction, thus realizing the previously described flexible adjustment of the control elements.

[0060] A further development of the invention provides that the air deflection element and / or the vortex guide element has a fluid-tight buoyancy chamber filled with a gas that has a lower density than air. The vortex guide element and / or the air deflection element is therefore designed as a buoyancy body. With the help of the gas, lift is generated which is, or at least can be, decoupled from the actual thrust of the engine. For example, the engine is designed such that a large part of the lift required to lift the missile is already generated using the gas present in the buoyancy chamber. The remaining lift is provided by the thrust of the engine, for which its thrust vector is adjusted accordingly. For example, helium or the like is used as the gas. The gas enables particularly energy-efficient operation of the engine or missile.

[0061] A further development of the invention provides that at least one usable space of the missile, in particular a passenger compartment and / or a cargo compartment, is arranged in the air deflection element and / or the vortex guide element (respectively). For this purpose, the air deflection element and / or the vortex guide element are dimensioned accordingly so that the engine has a corresponding size. In the passenger compartment, for example, at least one passenger seat is arranged, in particular several passenger seats, which are arranged, for example, in several rows. The cargo compartment serves to accommodate cargo, in particular luggage and / or transported goods. It also has a corresponding size for this purpose. For loading and unloading the usable space, the air deflection element has at least one reversibly closable access opening, for example in the form of a door, a gate, a hatch or the like.

[0062] A fuel tank for holding fuel and / or an energy storage device for temporarily storing electrical energy can also be arranged in the usable space. The fuel and / or the temporarily stored electrical energy are preferably used to operate the drive device. For this purpose, for example, the fuel tank is fluidically connected and / or the energy storage device is electrically connected to the drive device. It can be provided to form a usable space in each of the vortex guide element and the air deflection element. For example, the cargo space and / or the fuel tank and / or the energy storage device are arranged in the usable space of the air deflection element. The usable space of the vortex guide element, on the other hand, serves as the passenger compartment. In this case, the usable space of the air deflection element is preferably depressurized relative to the outside environment, whereas the usable space of the vortex guide element has an overpressure relative to the outside environment.

[0063] Further preferred embodiments of the engine are explained below, the features of which can be used alternatively or additionally. For example, the air deflection element overlaps the vortex guide element in the radial direction, starting from its longitudinal center axis, by at least 25%, at least 50%, at least 75%, or at least 100%. It may therefore already be sufficient to achieve an overlap of at most 50%, for example by at least 25%, at least 30%, at least 40%, or at least 50%. However, an overlap of at least 50% or more, in particular at least 60% or at least 75%, is preferred. The overlap can also be at least 80%, at least 90%, or at least 100%.In the latter case, the air deflection element completely overlaps the vortex guide element in the radial direction, in particular exactly completely, i.e. it does not protrude beyond the vortex guide element, so that it is flush with it on the radial outside. However, it can also be provided that the air deflection element extends beyond the vortex guide element in the radial direction, i.e. is larger than it in the radial direction. For example, the air deflection element has dimensions in the radial direction that are larger than the dimensions of the vortex guide element in the same direction. In particular, the dimensions of the air deflection element in the radial direction are at least 105% or at least 110% of the dimensions of the vortex guide element.

[0064] However, the air deflection element is particularly preferably as small as possible in the radial direction in order to avoid flow losses. The extent of the overlap is preferably selected such that the separation-free flow around the vortex guide element by the air exiting from the air outlet opening is achieved and is ideally not greater. At least a portion of the air exiting from the air outlet opening and subsequently from the air outlet gap should rest against the vortex guide element in such a way that it flows again to the air inlet opening and is conveyed through this into the intake duct again. For example, an overlap of the vortex guide element by the air deflection element in the radial direction by a maximum of 90%, a maximum of 80%, or a maximum of 70% is sufficient for this purpose.

[0065] The air deflection element, for example, has a volume that at least corresponds to a volume of the vortex guide element. Preferably, the volume of the air deflection element is larger than the volume of the vortex guide element, in particular it is larger by a factor of at least 1.25, at least 1.5, at least 1.75, or at least 2. Thus, the air deflection element is preferably available to accommodate a usable space of the missile. The usable space can, for example, comprise or be present as a passenger compartment and / or a cargo compartment. However, it can also be provided that the volume of the air deflection element corresponds at most to the volume of the vortex guide element or is smaller than this. For example, the volume of the air deflection element is at most 75%, for example at most 70%, at most 60%, or at most 50%, of the volume of the vortex guide element.In such a configuration, it can be provided that the usable space is arranged in the vortex guide element.

[0066] It can be provided that the air deflection element has an extension in the axial direction that corresponds at least to an extension of the vortex guide element in the same direction. Preferably, the extension of the air deflection element in the axial direction is greater than that of the vortex guide element, in particular by a factor of at least 1.25, at least 1.5, at least 1.75, or at least 2. As a result, the large volume of the air deflection element described above can be realized in a simple manner, so that, for example, the usable space is designed to be spacious. The invention further relates to a method for operating an engine for a missile, in particular an engine according to the embodiments in the context of this description, wherein the engine has an annular vortex guide element,which, viewed in section, has an air inlet opening arranged centrally with respect to a longitudinal central axis of the engine and, at a distance from the air inlet opening, an air outlet opening arranged centrally with respect to the longitudinal central axis, which are fluidically connected to one another via an intake duct delimited by the vortex guide element and accommodating an air conveying device, wherein the air outlet opening is overlapped by an air deflection element arranged geodetically above the vortex guide element during normal operation of the engine, which air deflection element extends radially outwards from the air outlet opening, so that it delimits, together with the vortex guide element, an air outlet gap which is in fluid communication with the air outlet opening.

[0067] It is provided that the vortex guide element is present as a rotational body which is formed by rotation of a closed curve around a rotational axis which has a continuous course at least on its radially outer side, and that the air inlet opening opens directly into an external environment of the engine, so that when the engine is operated as intended, air is conveyed from the side of the engine facing away from the air deflection element through the air inlet opening into the intake duct.

[0068] The advantages of such an engine design and such a procedure have already been pointed out. Both the engine and the method for its operation can be further developed according to the explanations in this description, so reference is made to these in this regard.

[0069] As already explained, the engine operates in such a way that the support vortex forms around the vortex guide element. This draws in additional air from the outside environment and transports it beneath the engine, where it serves to provide thrust. The support vortex thus ultimately serves as a conveying medium for air from the outside environment, which is drawn in from the side of the air deflection element facing away from the vortex guide element and / or from the area surrounding the vortex guide element and is then, at least temporarily, added to the support vortex.

[0070] The air exiting the air outlet gap and the air from the outside environment drawn into the support vortex are conveyed by the support vortex to the side of the vortex guide element facing away from the air deflection element, namely partially up to the longitudinal center axis. From there, part of the air is conveyed through the air inlet opening into the intake duct, while another part of the air is deflected in the direction of the vortex guide element facing away from the air guide element to generate a thrust jet of the engine and thus the engine thrust. Part of the air conveyed by the support vortex in the direction of the longitudinal center axis is thus deflected towards the vortex guide element, and another part is deflected in the direction away from the vortex guide element.

[0071] The invention further relates to a missile with at least one engine according to the embodiments within the scope of this description, wherein the engine has an annular vortex guide element which, viewed in section, has an air inlet opening arranged centrally with respect to a longitudinal central axis of the engine and, at a distance from the air inlet opening, an air outlet opening arranged centrally with respect to the longitudinal central axis, which are fluidically connected to one another via an intake duct delimited by the vortex guide element and accommodating an air conveying device, wherein the air outlet opening is overlapped by an air deflection element which, during normal operation of the engine, is arranged geodetically above the vortex guide element and which extends radially outwards from the air outlet opening,so that it defines, with the vortex guide element, an air outlet gap that is in flow connection with the air outlet opening.

[0072] It is provided that the vortex guide element is in the form of a rotational body which is formed by the rotation of a closed curve around a rotational axis which has a continuous course at least on its radially outer side, and that the air inlet opening opens directly into an external environment of the missile, so that when the engine is operated as intended, air is conveyed from the side of the engine facing away from the air deflection element through the air inlet opening into the intake duct.

[0073] With regard to the advantages and possible advantageous further training, reference is again made to the further explanations in this description.

[0074] A further development of the invention provides that the missile is designed as an aircraft or as an airworthy motor vehicle. In the case of the design as an aircraft, a usable space of the aircraft, for example a passenger compartment or cargo hold, is preferably located in the air deflection element. The engine here forms the missile or, to put it another way, the missile consists entirely or at least substantially entirely of the engine. Of course, the missile can also have multiple engines arranged at a distance from one another. If, on the other hand, the missile is designed as an airworthy motor vehicle, it preferably comprises multiple engines. These are arranged at a distance from one another on the motor vehicle in order to temporarily lift it off the ground.

[0075] The invention is explained in more detail below with reference to the exemplary embodiments illustrated in the drawings, without limiting the invention insofar as these fall within the scope of the claims. The sole figure shows a schematic representation of a missile with an engine.

[0076] The figure shows a schematic longitudinal sectional view of a missile 1 with an engine 2 for providing propulsion for the missile 1. In the exemplary embodiment shown here, the missile 1 essentially consists of the engine 2. Of course, the missile can also have several engines 2, which in this case are connected to one another via a common structure.

[0077] The engine 2 has an annular vortex guide element 3. In the exemplary embodiment shown here, the vortex guide element 3 is designed as a rotating body, in particular as a rotational torus, with respect to a longitudinal central axis 4 of the vortex guide element 3. The longitudinal central axis 4 is also the longitudinal central axis of the missile 1. The vortex guide element 3 continuously and completely encompasses an intake duct 5 with an air inlet opening 6 and an air outlet opening 7 in the circumferential direction. An air conveying device 8 is arranged in the intake duct 5, which is designed, for example, as a propeller and can be driven by a drive device (not shown here). Both the air inlet opening 6 and the air outlet opening 7 are arranged centrally with respect to the longitudinal central axis 4. In this respect, they are coaxial with one another.

[0078] The vortex guide element 3 is overlapped at least in part by an air deflection element 9. The air deflection element 9 also has a longitudinal central axis, which in the exemplary embodiment shown here coincides with the longitudinal central axis 4. The air deflection element 9 is arranged centrally with respect to the vortex guide element 3 and thus overlaps at least the air outlet opening 7, namely completely in the radial direction. Shown is an exemplary embodiment of the missile 1 or the engine 2 in which the air deflection element 9 extends in the radial direction beyond the vortex guide element 3. In other words, the air deflection element 9 completely overlaps the vortex guide element 3 in section and projects outwards beyond it in the radial direction.

[0079] The vortex guide element 3 and the air deflection element 9 jointly define a radial channel 10, which, on the one hand, originates from the air outlet opening 7 and, on the other hand, extends to an air outlet gap 11. It can be seen that, in the exemplary embodiment illustrated here, the radial channel 10 continuously decreases in size from the air outlet opening 7 to the air outlet gap 11, i.e., has a decreasing flow cross-section. For this purpose, an air deflection surface 12 of the air deflection element 9 continuously approaches an air guide surface 13 of the vortex guide element 3 in the radially outward direction.

[0080] The vortex guide element 3 is cut centrally in the axial direction with respect to the longitudinal center axis 4 by an imaginary plane 14, which divides the vortex guide element 3, seen in section, into a first profile surface 15 and a second profile surface 16. The first profile surface 15 is located on a side of the air guide element 3 facing away from the air deflection element 9, whereas the second profile surface 16 is arranged on a side of the vortex guide element 3 facing the air deflection element 9. It can be seen that the air conveying device 8 is also arranged approximately centrally in the axial direction in the intake duct 5, so that the imaginary plane 14 intersects the air conveying device 8. The air conveying device 8 is mounted on a projection 17 which extends from a base body 18 of the air deflection element 9. The projection 17 extends through the air outlet opening 7 into the intake duct 5.

[0081] The engine 2 is intended to be operated in such a way that air from an external environment 19 is conveyed through the air inlet opening 6 into the intake duct 5. The air is then conveyed from the intake duct 5 via the air outlet opening 7 into the radial duct 10, from which it finally exits again through the air outlet gap 11 into the external environment 19. In this case, the air is deflected by at least 90°, at least 135°, at least 150°, at least 165° or at least 180°. In the exemplary embodiment shown here, the air is deflected by almost 180° after entering the intake duct 5 through the air inlet opening 6 until it exits the radial duct 10 through the air outlet gap 11. The air is therefore expelled from the engine 2 in the opposite direction to that in which it was conveyed into it.

[0082] This also applies to the entire missile 1, the lowermost part of which is formed by the engine 2. This means that no further element of the missile 1 and / or the engine 2 is arranged on the side of the vortex guide element 3 facing away from the air deflection element 9. The air inlet opening 6 is designed to be free of overlap, so that a free airspace arranged below the air inlet opening 6 is present in the external environment 19 or forms part of the external environment 19. The free airspace below the air inlet opening 6 is completely filled with air. In other words, there is no further element of the missile 1 and / or the engine 2 between the vortex guide element 3 and a floor 20 above which the missile 1 is located, so that the latter is designed to be free of obstructions or blockages.

[0083] By conveying the air into the intake duct 5 through the air inlet opening 6 and expelling the air through the air outlet gap 11, a supporting vortex 21 is generated, which, viewed in section, surrounds the vortex guide element 3. The supporting vortex 21, like the vortex guide element 3, is toroidal, in particular rotationally toroidal. The thrust of the engine 2 is now achieved, on the one hand, by a higher air flow velocity in the radial duct 10 compared to an air flow velocity outside the radial duct 10 or on the side of the vortex guide element 3 opposite the radial duct 10.

[0084] A further portion of the thrust is provided, at least temporarily, by means of the support vortex 21. The support vortex conveys air from the external environment 19 along the streamlines 22 shown here purely as an example to the side of the vortex guide element 3 facing away from the air deflection element 9. In particular, air is also sucked in from the side of the air deflection element 9 facing away from the vortex guide element 3 and conveyed along the streamlines 22 to the opposite side of the engine 2. As a result, a thrust jet 23 is formed on the side of the vortex guide element 3 facing away from the air deflection element 9, which thrust jet produces the aforementioned portion of the thrust. The support vortex 21 thus functions as an air conveying means, which significantly increases the efficiency of the air conveying device 8.

[0085] In the arrangement of vortex guide element 3 and air deflection element 9 shown here, a thrust vector of the engine 2 is aligned parallel to the longitudinal center axis 4. In order to tilt the thrust vector and thus enable control of the missile 1, the vortex guide element 3 and the air deflection element 9 can be displaced relative to one another, namely in such a way that the size of the air outlet gap 11 can be changed, in particular locally. This means that the size of the air outlet gap 11 is either changed uniformly over the circumference of the engine 2, or unevenly. For example, the air outlet gap 11 is enlarged on one side of the engine 2 and reduced on the opposite side, resulting in different flow velocities of the air flowing out of the air outlet gap 11.

[0086] The described missile 1 has the advantage of being extremely energy-efficient due to the use of the air vortex 21 to provide at least part of the thrust. Furthermore, the missile 1 can be controlled extremely precisely by shifting the vortex guide element 3 and the air deflection element 9 relative to each other. In particular, the missile 1 can hover in the air similar to a helicopter. Nevertheless, it can achieve quite high speeds because, unlike a helicopter, it is not limited by a maximum flow velocity at the blade tips of a rotor.

Claims

1. Engine (2) for a flying body (1), having an annular vortex guide element (3) which, seen in section, has an air inlet opening (6) arranged centrally with respect to a longitudinal central axis (4) of the engine (2) and, at a distance from the air inlet opening (6), an air outlet opening (7) arranged centrally with respect to the longitudinal central axis (4), which are connected to one another in terms of flow via an intake duct (5) which is bounded by the vortex guide element (3) and accommodates an air conveying device (8), wherein the air outlet opening (7) is overlapped by an air deflecting element (9) which is arranged geodetically above the vortex guide element (3) when the engine (2) is operating as intended, which extends radially outwards from the air outlet opening (7) so that, together with the vortex guide element (3), it delimits an air exit gap (11) which is in flow communication with the air outlet opening (7), wherein the vortex guide element (3) is in the form of a body of rotation which is formed by rotation about an axis of rotation of a closed curve continuously comprising a continuous course at least on its radially outer side, characterised in that the air inlet opening (6) opens directly into an outer environment (19) of the engine (2), so that a free air space is present in an imaginary extension of the intake duct (5) on the side of the air inlet opening (6) and, when the engine (2) is operating as intended, air is conveyed from the side of the engine (2) facing away from the air deflecting element (9) through the air inlet opening (6) directly from the outer environment into the intake duct (5).

2. Engine according to claim 1, characterised in that the vortex guide element (3), seen in section, is bounded on one side by a first profiled surface (15) and on the other side by a second profiled surface (16), wherein the two profiled surfaces (15, 16) merge directly and continuously into one another on both sides.

3. Engine according to one of the preceding claims, characterized in that the vortex guide element (3) is formed as a body of rotation.

4. Engine according to one of the preceding claims, characterized in that the air exit gap (11) is in flow connection with the air outlet opening (7) via a radial duct (10) which has a flow cross-section which decreases in the direction of the air exit gap (11), so that it is designed in the manner of a nozzle.

5. Engine according to one of the preceding claims, characterized in that the air deflecting element (9) completely overlaps the vortex guide element (3) in the radial direction.

6. Engine according to one of the preceding claims, characterised in that the air deflecting element (9) comprises a projection (17) engaging in the intake duct (5), to which projection a drive device for driving the air conveying device (8) is attached.

7. Engine according to one of the preceding claims, characterised in that an air deflecting surface (12) of the air deflecting element (9) which bounds the radial duct (10) and faces the vortex guide element (3) is continuously curved when viewed in section.

8. Engine according to one of the preceding claims, characterised in that, seen in section, the radius of curvature of the air deflecting surface (12) is greater than a radius of curvature of an air guide surface (13) of the vortex guide element (3) bounding the radial duct (10).

9. Engine according to one of the preceding claims, characterised in that the radius of curvature of the air deflecting surface (12) and the radius of curvature of the air exit gap (13) are selected in such a way that the flow cross-section of the radial duct (10) decreases continuously from the air outlet opening (7) to the air exit gap (11).

10. Engine according to one of the preceding claims, characterized in that the vortex guide element (3) is displaceable with respect to the air deflecting element (9) for globally and / or locally changing a flow cross-section of the air exit gap (11).

11. Engine according to one of the preceding claims, characterized in that the air deflecting element (9) and / or the vortex guide element (3) comprises a fluid-tight buoyancy chamber filled with a gas having a lower density than air.

12. Engine according to one of the preceding claims, characterized in that at least one useful space of the flying body (1) is arranged in the air deflecting element (9) and / or the vortex guide element (3).

13. Method for operating an engine (2) for a flying body (1), in particular an engine (2) according to one or more of the preceding claims, wherein the engine (2) has an annular vortex guide element (3) which, seen in section, has an air inlet opening (6) arranged centrally with respect to a longitudinal central axis (4) of the engine (2) and, at a distance from the air inlet opening (6), an air outlet opening (7) arranged centrally with respect to the longitudinal central axis (4), which are connected to one another in terms of flow via an intake duct (5) which is bounded by the vortex guide element (3) and accommodates an air conveying device (8), wherein the air outlet opening (7) is overlapped by an air deflecting element (9) which is arranged geodetically above the vortex guide element (3) when the engine (2) is operating as intended, which extends radially outwards from the air outlet opening (7) so as to delimit with the vortex guide element (3) an air exit gap (11) which is in flow communication with the air outlet opening (7), wherein the vortex guide element (3) is in the form of a body of rotation which is formed by rotation about an axis of rotation of a closed curve continuously comprising a continuous course at least on its radially outer side, characterized in in that the air inlet opening (6) opens directly into an outer environment (19) of the engine (2), so that a free air space is present in an imaginary extension of the intake duct (5) on the side of the air inlet opening (6) and, when the engine (2) is operating as intended, air is conveyed from the side of the engine (2) facing away from the air deflecting element (9) through the air inlet opening (6) directly from the outer environment into the intake duct (5).

14. Flying body (1) with at least one engine (2) according to one or more of the claims 1 to 12.

15. Flying body according to claim 14, characterised by a design as an aircraft or as a motor vehicle capable of flight.