Engine arrangement for an aircraft, and aircraft

Abstract

The invention relates to an engine arrangement for an aircraft, having a first engine, at least one second engine and a reference axis, wherein the first engine has a first basic body with a first longitudinal axis and has a first drive body rotating about the first longitudinal axis, the second engine has a second longitudinal axis and a second drive body rotating about the second longitudinal axis, the first engine and the second engine are arranged in ballistically effective proximity to each other with the respective longitudinal axis substantially parallel to the reference axis, and, in the event of mechanical damage, the first drive body and / or the second drive body output or outputs respective drive body parts hazardously acting ballistically in relation to the respective other engine and / or in relation to the respective other drive body substantially radially with respect to the respective longitudinal axis into a respective ballistic hazard area, wherein the first drive body and the second drive body are arranged offset with respect to each other along the reference axis in such a manner that the respective ballistic hazard area is arranged spaced apart along the reference axis from the respective drive body endangered by the hazardously acting drive body parts of the respective other drive body. Furthermore, the invention relates to an aircraft having such an engine arrangement.

Description

Engine arrangement for an aircraft and aircraft

[0001] The invention relates to an engine arrangement for an aircraft comprising a first engine, at least one second engine, and a reference axis, wherein the first engine has a first base body with a first longitudinal axis and a first drive body rotating about the first longitudinal axis, the second engine has a second longitudinal axis and a second drive body rotating about the second longitudinal axis, the first engine and the second engine are arranged with their respective longitudinal axes essentially parallel to the reference axis in ballistically effective proximity to each other, and in the event of mechanical damage, the first drive body and / or the second drive body emit or emit drive body parts that are ballistically dangerous to the respective other engine and / or drive body, essentially radially to the respective longitudinal axis, into a respective ballistic danger zone.wherein the first engine and at least the second engine are arranged in a fuselage of the aircraft. The invention further relates to an aircraft with such an engine arrangement.

[0002] Previous engine configurations for aircraft, especially where two engines are arranged in close proximity, are often symmetrical and therefore require high-performance ballistic missiles. Protective devices are used to shield one engine from fragments ejected by another, for example, in the event of engine failure in the latter. This adds unnecessary weight to the aircraft. If such engines are to be located near or within the fuselage, additional protection becomes necessary.

[0003] Engine arrangements are also known on aircraft, for example, where the engines are far enough apart to eliminate any risk of mutual collision.

[0004] The US 5,855,340 reveals a business jet with engines of varying power, but without any apparent ballistic protection.

[0005] US patent 2019 / 0091749 A discloses a commercial aircraft in which the engines are arranged on the respective wings. Several engines are arranged on one wing, offset from each other in the longitudinal direction due to the sweep of the wings.

[0006] The DE 10 2014 208 921 Al shows an engine external structure that also serves as a ballistic protection structure for the engine in question.

[0007] US 2018 / 0134406 Al describes an aircraft which has an additional engine in the rear area.

[0008] US 2017 / 0137135 shows an aircraft with engine inlets arranged offset from each other.

[0009] US document 3,237,891 reveals an arrangement of three engines in the rear section of an aircraft.

[0010] In DE 693 10 344 T2, two axially offset engines are shown on an aircraft wing, with one engine located above the wing and one engine located below the wing.

[0011] US 2005 / 0178890 describes a business aircraft with differently sized engines in the fuselage, but without specific ballistic protection.

[0012] US patent 2019 / 0031363 A1 discloses a system and a method for operating a shrouded propeller for suctioning a boundary layer. In this system, some components of the drive system are arranged axially.

[0013] WO 2017 / 085405 Al shows a commercial aircraft with an engine arrangement on the wings and in the tail area.

[0014] The purpose of the invention is to improve the state of the art.

[0015] The problem is solved by an engine arrangement for an aircraft with a first engine, at least one second engine and a reference axis, wherein the first engine has a first base body with a first longitudinal axis and a first drive body rotating about the first longitudinal axis, the second engine a a second longitudinal axis and a second propulsion unit rotating about the second longitudinal axis, the first engine and the second engine are arranged with their respective longitudinal axes substantially parallel to the reference axis in ballistically effective proximity to each other, and in the event of mechanical damage, the first engine unit and / or the second engine unit emits or emits propulsion unit parts that are ballistically hazardous to the respective other engine unit and / or to the respective other propulsion unit, substantially radially to the respective longitudinal axis into a respective ballistic hazard zone, wherein the first engine unit and the at least second engine unit are arranged in a fuselage of the aircraft, wherein the first engine unit and the second engine unit are arranged offset from each other along the reference axis such that the respective ballistic hazard zone is separated from the respective,The drive body, which is endangered by the hazardous drive body parts of the respective other drive body, is arranged at a distance along the reference axis, wherein a ballistic protection element is arranged on the first base body, on the second base body and / or between the first base body and the second base body, wherein the ballistic protection element is configured to slow down and / or restrain the respective drive body parts that are ballistically hazardous to the respective other engine and / or to the respective other drive body below a hazardous velocity.

[0016] The core concept of the invention is that a first propulsion unit and a second propulsion unit are arranged offset from each other along the reference axis such that the respective ballistic hazard zone is spaced apart from the respective propulsion unit endangered by the hazardous propulsion unit components of the other propulsion unit along the reference axis. Thus, mechanically, solely through the geometric arrangement of the respective propulsion units relative to each other along the reference axis in the fuselage of the aircraft, a hazard to critical components of the other propulsion unit or to the fuselage structure, for example, from detached turbine blades in a jet engine, is excluded. The ballistic protection element serves to catch and / or slow down components that are accelerated to eject in the event of a failure and, in conjunction with the offset propulsion units, can be designed to be as lightweight as possible.

[0017] The following terms will be explained in more detail in this context:

[0018] In this context, an "engine configuration" refers to the design-driven positioning of different engines for an aircraft, such that, for example, the position of a first engine relative to a second engine is deliberately chosen to achieve the desired geometric configuration between the engines. An "aircraft" in this context could be, for example, a helicopter or an airplane. or be a propulsion system for a motorized paraglider. The aircraft has a respective "engine", i.e. a propulsion unit, in particular an engine that generates thrust through combustion power.

[0019] A "reference axis" is, for example, an axis that runs essentially parallel to a longitudinal axis of the respective engine or is geometrically averaged between several engines, such that a geometric reference is established for radially exiting engine body components of the respective engines. Depending on the engine type, the reference axis can also be parallel to an axis along which thrust from the respective engine acts. This longitudinal axis is, in particular, the axis around which the engine components, such as the respective engine body, rotate and to which engine body components can exit in an orthogonal direction. For example, in the case of a jet engine, the reference axis would be arranged essentially parallel to the axis of rotation of turbine components, and in the case of a piston engine, essentially parallel to a crankshaft.

[0020] A "basic body" describes the housing of the respective engine, whereby the basic body may, for example, include additional components such as gearboxes, generators, and the like. Furthermore, the engine has a "longitudinal axis," which also serves as the axis of rotation for rotating drive components. For example, a "drive body" rotates, which describes the rotating parts in a jet engine and, for example, refers to pistons and connecting rods with crankshaft in a piston engine, around the longitudinal axis.

[0021] In connection with the invention, it should be mentioned that the corresponding engines are arranged "in ballistically effective proximity" to each other, i.e., at a distance such that components breaking off or emanating from the respective propulsion body can be harmful to the other propulsion body and / or the other engine. Accordingly, "propulsion body parts," i.e., components originating from or emanating from the propulsion body, become ballistically effective against the other engine, for example, by causing damage through kinetic energy upon impact. By design, in an engine with a rotating propulsion body, a hazard is generated essentially radially to the respective longitudinal axis, i.e., radially emanating from the longitudinal axis. The "ballistic danger zone" describes the area in which propulsion body parts can move or impact.

[0022] The "fuselage" describes the main structure of the aircraft, to which components such as wings, empennage, and auxiliary systems like the landing gear are attached and mechanically fixed. In particular, the fuselage is designed as a fuselage shell with, for example, a cylindrical cross-section, with aerodynamic constrictions at the corresponding ends of the fuselage. purposes are undertaken, so that, for example, the End areas are rounded or tapered.

[0023] “Arranged offset from each other along the reference axis” describes a deliberate selection of a corresponding location for the respective engine, so that a longitudinal offset is created along the longitudinal axis and thus the corresponding drive units are arranged longitudinally offset from each other.

[0024] A "ballistic protection element" describes an assembly or component designed and applied to reduce the kinetic energy of ejected drive components, thus preventing them from posing a further hazard. For example, such a ballistic protection element can consist of a steel sheet, a titanium sheet, and / or alternatively used or combined fabrics, such as aramid fibers and / or glass fibers. Various ballistic protection systems are known, allowing the ballistic protection element to incorporate both hard materials for breaking up drive components and soft elements, such as an aramid fabric, to further reduce the velocity of the fragmented drive components.

[0025] According to one embodiment, for example, a respective compressor wheel of a first engine can be arranged such that a respective compressor wheel of a The second engine cannot be hit in the event of damage with radially protruding compressor wheel parts. The same applies to corresponding turbine wheels or other components of the engine block in an engine. For example, corresponding engine components, especially of the engine block, can be displaced relative to each other by more than 10%, 15%, 25%, or especially more than 35% of the total length of the respective engine along the reference axis. This allows the ballistic protection element to be designed much more easily, since simultaneous failure of the different engines in different areas along the reference axis is to be expected.

[0026] The ballistic protection element in the respective engine body and / or between the respective engine bodies serves to retain any components that might nevertheless escape, corresponding to the components arranged side by side along the reference axis. The respective ballistic protection element is specifically designed to slow down and / or retain the respective engine body components that pose a ballistic hazard to the respective other engine and / or the respective other propulsion body below a certain hazard velocity. In this context, it should be noted that by appropriately shifting the respective engines relative to each other along the reference axis, it is ensured that, for example, only components with lower energy, such as a turbine stage, are affected. With smaller turbine blades and a smaller radius of movement, debris can exit the engine's main body, and therefore the ballistic protection element must be significantly less powerful than in conventional engine configurations. A hazard velocity describes the speed sufficient to cause such components, for example shrapnel, to damage components of another engine.

[0027] The ballistic protection, in one form, is in particular a synthetic fiber fabric, especially an aramid fabric and / or a polyamide fabric, a hardened steel, titanium, and / or a ceramic, or it incorporates these respective components. The respective components are designed, in particular, as composite protection, in which, for example, a hard component such as ceramic or hardened steel can break up corresponding shrapnel fragments, which are then, for example, contained by an aramid fabric. In this context, the term "spall liner" is also used.

[0028] In one embodiment, a first engine and at least the second engine can be arranged in a rear area of ​​the fuselage of the aircraft.

[0029] A "tail section" is, in particular, a section of the fuselage comprising the rear 25%, 20%, or especially 15% of the aircraft, and in particular of the aircraft fuselage. An arrangement of the engines in The rear area reduces noise emissions to the interior, thus making the aircraft more comfortable.

[0030] If the first and second engines are arranged one above the other and, in particular, in a plane of symmetry of the aircraft along the direction of flight, then, for example, engines of different power levels can be used, which, despite the close spatial proximity, for example in the rear area of ​​an aircraft fuselage, can be designed with significantly less ballistic protection and still maintain a high level of safety for the aircraft.

[0031] For example, a component that is primarily relevant to damage, such as a first compressor wheel, which is highly likely to form shrapnel in the event of a bird strike, can even be positioned along the reference axis outside the other engine. This means that the area most at risk from shrapnel lies outside the contour of the other engine. For example, this can be chosen for the more powerful of two engines so that the component with the highest failure risk, namely the compressor wheel of the more powerful engine, is positioned in such a way that a failure of the more powerful engine would prevent fatal consequences for the less powerful engine.

[0032] An engine can be a turbine jet engine, in particular a single-flow jet engine, a This could be a turbofan engine or a turboprop engine. Particularly in the case of turboprop engines, the respective turbine unit is arranged according to the invention in such a way that the mutual risk in the event of a failure is mitigated and minimized with the arrangement according to the invention using a relatively lightweight ballistic protection element.

[0033] In another aspect, the problem is solved by an aircraft that benefits from the engine arrangement according to one of the previous embodiments.

[0034] The invention will now be explained in more detail using exemplary embodiments. These will show... Figure 1 is a schematic representation of a business jet in a side view, as well as Figure 2 is a detailed view of a Engine arrangement of the Business jet of Figure 1.

[0035] A business jet 101 has a fuselage structure 103. The fuselage structure 103 serves as part of the wing structure of the business jet 101 and has windows 105 that serve as the cockpit window. The business jet 101 is shown in a conventional configuration with a vertical stabilizer 111, a horizontal stabilizer 113, and a wing 115 as a low-wing monoplane with a conventional tail assembly. The vertical stabilizer 111 and the horizontal stabilizer 113 are located at the tail 107.

[0036] The wing 115 features lift-enhancing devices 117, such as flaps, to increase lift in certain flight situations like takeoff and landing. Furthermore, the business aircraft 101 has a main landing gear 121 and a nose landing gear 123, both of which are retractable.

[0037] In the rear of 107 are two engines, namely an engine 151 with an air intake 153 and a nozzle 155 and an engine 161 with an air intake 163 and a nozzle 165. Engines 151 and 161 are turbofan engines that operate on the principle of a gas turbine with an additional bypass fan (not shown in detail). The engines draw in air through the corresponding air intakes 153 and 163, increase the energy contained in the air through combustion in their respective combustion chambers (not shown), and expel the resulting hot, accelerated exhaust gases, along with the accelerated air masses from the bypass fan, through the respective nozzles 155 and 165. This generates thrust for the 101 business jet, enabling it to accelerate. The 101 business jet weighs approximately 5,000 kg in its fully loaded takeoff configuration, which corresponds to a force of approximately 49,000 N.Engine 151 has a maximum thrust of approximately 1,500 N, whereas engine 161 has a maximum thrust of 2,500 N.

[0038] Thus, the 151 engine, with its maximum thrust, is designed to operate the 101 business jet safely and efficiently, especially during cruise flight. Whereas engine 161, with its significantly higher thrust, is used to provide sufficient performance for business aircraft 101, for example, in hot-and-high conditions and / or when particularly short takeoff and landing distances are required. The maximum thrust of engine 151 is selected to ensure that the necessary power for the aircraft's total weight is available in accordance with certification requirements, even if an aborted takeoff is no longer possible after a so-called decision capability has been reached, thus guaranteeing a safe climb for business aircraft 101. Similarly, only the power of engine 151 can be used if, for example, sufficient runway is available for a long takeoff procedure. Engine 161, which is then idling, can remain idle without impacting maintenance-relevant operating hours, and corresponding fuel savings can be achieved.

[0039] An engine arrangement 201 comprising a shaft 156 of engine 151 and a shaft 166 of engine 161 along the longitudinal axis 191 (see also Figure 2) is designed such that, in the event of a failure of a compressor wheel 162 of the more powerful engine 161, any resulting shrapnel 167 can exit within a danger zone 169, the danger zone 169 being completely outside the contour of engine 151. The shrapnel 167 thus cannot strike engine 151. A ballistic shield 181 is arranged between engines 151 and 161, which is divided into several The system consists of layers, namely a titanium layer 183, an aramid fabric 185, and another titanium layer 187, wherein the respective titanium layers 183 and 187 face the engines and the aramid fabric 185 is arranged between them. In the event of a failure of a relatively smaller compressor wheel 152 of engine 151 or the failure of respective turbine stages 154 and 164, which each emit shrapnel of lower energy, the ballistic protection 181 can be designed to be significantly smaller than if, for example, in a parallel arrangement of both engines, an exit path of shrapnel 167 and thus the danger zone 169 were in overlap with engine 151.

[0040] The arrangement of the protection 181 serves such a purpose that the respective titanium layer 183 or 187 breaks up the shrapnel pieces sent by the respective engine 151 or 161 and these are then captured in the aramid fabric 185, thus realizing a composite armor in the protection 181. Reference character list 101 business plane 103 Hull structure 105 disc 107 Rear 111 Vertical stabilizer 113 Horizontal stabilizer 115 Wing 117 buoyancy aids 121 Main landing gear 123 Nose landing gear 151 Engine 152 compressor wheel 153 Air intake 154 Turbine stage 155 nozzle 156 wave 161 Engine 162 compressor wheel 163 Air intake 164 Turbine stage 165 nozzle 166 wave 167 shrapnel pieces 169 Danger area 181 Protection 183 Titanium layer 185 Aramid fabric 187 Titanium layer 201 Engine arrangement

Claims

Patent claims:

1. Engine arrangement (201) for an aircraft (101) comprising a first engine (161), at least one second engine (151) and a reference axis (191), wherein the first engine (161) has a first base body (161) with a first longitudinal axis (166) and a first drive body (162, 164, 166) rotating about the first longitudinal axis (166), the second engine (151) has a second longitudinal axis (156) and a second drive body (152, 154, 156) rotating about the second longitudinal axis (156), the first engine (161) and the second engine (151) are arranged with their respective longitudinal axes (156, 166) substantially parallel to the reference axis (191) in ballistically effective proximity to each other, and the first drive body (162, 164, 166) and / or the second drive body (152, 154,156) in the event of mechanical damage, the respective propulsion body parts (167) emit or emit ballistically dangerous propulsion components (167) towards the respective other engine and / or propulsion body, substantially radially to the respective longitudinal axis, into a respective ballistic danger zone (169), wherein the first engine (161) and the at least second engine (151) are arranged in a fuselage (103) of the aircraft (101), characterized in that the first propulsion body (162, 164, 166) and the second propulsion body (152, 154, 156) are arranged offset from each other along the reference axis (191) such that the respective ballistic danger zone (169) is spaced apart from the respective propulsion body endangered by the dangerous propulsion body parts (167) of the respective other propulsion body along the reference axis, wherein a ballistic protection element (181) is attached to the first base body, (161) , on the second base body (151) and / or between the first base body (161) and the second base body (151), wherein the ballistic protection element (181) is configured to slow down and / or restrain the respective propulsion body parts which pose a ballistic danger to the respective other engine and / or propulsion body below a danger velocity.Engine arrangement according to claim 1, characterized in that the first drive body (162, 164, 166) has a first compressor wheel (162) and a first turbine wheel (164) and / or the second drive body (152, 154, 166) has a second compressor wheel (152) and a second turbine wheel (154), wherein the first compressor wheel (162) and the second compressor wheel (152) and / or the first turbine wheel (164) and the second turbine wheel (154) are arranged offset from each other along the reference axis (191) such that the respective ballistic danger zone (169) is spaced apart from the respective compressor wheel and / or turbine wheel endangered by the hazardous drive body parts (167) of the other compressor wheel and / or the other turbine wheel along the reference axis (191).Engine arrangement according to claim 1 or 2, characterized in that the first drive body (162, 164, 166) and the second drive body (152, 154, 156), the first compressor wheel (162) and the second compressor wheel (152) and / or the first turbine wheel (164) and the second turbine wheel (154) are arranged offset from one another along the reference axis (191) such that the respective ballistic danger zone (169) is separated from the respective drive body parts (167) that pose a danger. The drive body, compressor wheel, and / or turbine wheel, which are at risk of being damaged, are spaced apart by more than 10%, 15%, 25%, in particular more than 35% of a first total length of the first engine (161) and / or a second total length of the second engine (151) along the reference axis. Engine arrangement according to one of the preceding claims, characterized in that the ballistic protection (181) is a synthetic fiber fabric, in particular an aramid fabric (185) and / or a polyamide fabric, a steel, in particular hardened steel, titanium (183, 187), and / or a comprising ceramic, wherein the synthetic fiber fabric, the steel, the titanium and / or the ceramic is designed as a ballistically effective composite protection z (181). Engine arrangement according to one of the preceding claims, characterized in that the first engine (161) and the at least second engine (151) are arranged in a rear region (107) of the fuselage (103) of the aircraft (101). Engine arrangement according to one of the preceding claims, characterized in that the first engine (161) and the at least second engine (151) are arranged one above the other in a fuselage (103) of the aircraft (101), wherein the first engine (161) and the at least second engine (151) are arranged substantially in an aerodynamic plane of symmetry along a flight direction (191) of the aircraft (101).Engine arrangement according to one of the preceding claims, characterized in that the first engine (161) and the second engine (151) have different maximum power outputs, wherein In particular, a first maximum thrust of the first engine (161) is a maximum of 90%, 85%, 70%, 65%, 55%, 50%, and in particular a maximum of 45% of a second maximum thrust of the second engine (151). Engine arrangement according to one of the preceding claims, characterized in that the first engine (161) and / or the at least second engine (151) is a turbine jet engine, in particular a single-flow jet engine, a turbofan engine, or a turboprop engine. Aircraft (101) with an engine arrangement (201) according to one of the preceding claims.

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