Gas turbine for an aircraft

Abstract

The invention relates to a gas turbine (10) for an aircraft. The gas turbine (10) comprises a housing (12) with an inner housing (14) (12) which has a main flow channel (16) for a main flow (H), and an outer housing (18) (12) which has a bypass channel (20) for a bypass flow (N), a water system (22) with a heat exchanger (24) which can be supplied with the main flow (H), and at least one exhaust channel (26) through which the main flow (H) can be directed from the main flow channel (16) through the heat exchanger (24) to at least one outlet nozzle (28) of the housing (12) to the outside.The housing (12) also has at least one thrust reverser flap (36) which is movable between a thrust reversal position in which the thrust reverser flap (36) can be acted upon by the main flow (H) and the bypass flow (N) to reverse the thrust of the gas turbine (10) and a flight position in which the thrust reverser flap (36) does not reverse the thrust of the gas turbine (10).

Description

[0001] The invention relates to a gas turbine for an aircraft.

[0002] The so-called Water-Enhanced Turbofan (WET) is a propulsion concept that draws on MTU's extensive expertise. This concept utilizes the residual heat from the gas turbine exhaust gas. This is achieved by evaporating water using a steam generator, which is then injected into the combustion chamber. The water required for this is extracted from the exhaust gas using a water separation device. The basic technology is described, for example, in WO 2020 / 187345 A1 and, due to its design, has the potential to reduce emissions that are harmful to the environment and the climate. The propulsion system disclosed therein combines a gas turbine of the turbofan or turboprop type with a water system and a steam system. In a steam generator located downstream of the turbine, steam is generated from the exhaust gas of the main stream by transferring heat via a heat exchanger. This steam is then fed into the engine's combustion chamber.After passing through the steam generator, the moist exhaust gas passes through further components that serve to separate the water from the exhaust gas by cooling. This is a condenser of a water separation device.

[0003] In this configuration, however, the radial outer casing of the gas turbine or nacelle houses the condensers and water recovery heat exchangers, so that this otherwise usual position for the thrust reverser flaps is not available.

[0004] The object of the present invention is to provide a generic gas turbine for an aircraft which enables improved thrust reversal.

[0005] The object is achieved according to the invention by a gas turbine having the features of patent claim 1. Advantageous embodiments with expedient further developments of the invention are specified in the subclaims.

[0006] The invention relates to a gas turbine for an aircraft, in particular an airplane, comprising a housing with an inner housing having a main flow duct for a main flow, and an outer housing having a secondary flow duct for a secondary flow. The gas turbine further comprises a water system with a heat exchanger to which the main flow can be applied, and at least one exhaust duct through which the main flow can be guided from the main flow duct through the heat exchanger to at least one outlet nozzle of the housing. Improved thrust reversal is made possible according to the invention in that the housing has at least one thrust reversing flap which is movable between a thrust reversing position, in which the thrust reversing flap can be applied with the main flow and the secondary flow in order to reverse a thrust of the gas turbine, and a flight position in which the thrust reversing flap does not reverse the thrust of the gas turbine.In other words, the invention provides that the housing has one or more thrust reversing flaps which can be moved from a flight position without thrust reversal into a thrust reversing position with thrust reversal, in which position the thrust reversing flap(s) can be acted upon by the main flow and / or the bypass flow of the gas turbine, in particular both by the main flow and the bypass flow of the gas turbine, or is / are acted upon during operation of the gas turbine. The thrust reversing flap(s) can in principle be acted upon by a portion of the relevant flow or by the entire flow or a combination thereof. This makes it possible to achieve improved thrust reversal in a WET gas turbine. In general, it should be noted that the terms “axial” or “axial”, “radial” or “radial” and “circumferential” always refer to the machine orThe term "upstream" refers to the rotational axis of the gas turbine, unless the context implicitly or explicitly indicates otherwise. An axial direction of the gas turbine runs parallel to an engine axis, i.e., a shaft axis of a gas turbine drive shaft. A radial direction, accordingly, runs perpendicular to the engine axis. Finally, a circumferential direction of the gas turbine describes a direction around the engine axis. The terms "upstream" and "downstream" accordingly refer to the flow direction prevailing during operation of the turbomachine.

[0007] In an advantageous embodiment of the invention, the exhaust duct is arranged in a region between an outlet of the main flow duct and an outlet of the heat exchanger, in a crossflow arrangement with the secondary flow duct. The resulting crossflow arrangement, with a predominantly radially flowing main flow and a substantially axially flowing secondary flow, allows for a particularly simple and compact routing of the exhaust gas from the main flow duct into the outer casing of the gas turbine, in order to separate the water, on the one hand, and to discharge the remaining exhaust gas from the main flow from the casing, on the other.Alternatively or additionally, it is provided that the exhaust gas duct is arranged in a region downstream of the heat exchanger outlet in the opposite direction to the main flow duct, is deflected in a subsequent region, and runs at least substantially in the same direction as the secondary flow duct in a final region up to the outlet nozzle. In other words, it is provided that the exhaust gas duct is designed such that, after the main flow leaves the heat exchanger, it guides the main flow in some regions in a counter-axial direction with respect to the secondary flow, i.e. in the direction of an inlet of the gas turbine. The direction of the exhaust gas duct is then reversed in an axially forward part of the housing, after which the main flow is guided substantially in the axial direction, i.e. flowing in the same direction as the secondary flow, up to the outlet nozzle(s).In this way, the main flow can exit in a radially outer region of the casing that is axially displaced in the direction of an air inlet of the gas turbine, whereby the thrust reverser flap(s) can be particularly easily acted upon by both the secondary flow and the main flow, both of which can exit from the casing in the radially outer region of the casing.

[0008] In a further advantageous embodiment of the invention, it is provided that the at least one thrust reversing flap is arranged upstream of an outlet opening of the bypass duct. In other words, the bypass flow flows past the bypass duct, at least when the bypass flap is in the flight position, before leaving the housing downstream of the bypass flap. This ensures that the bypass flap can be acted upon by part or all of the bypass flow by moving it into the thrust reversing position. Alternatively or additionally, it is provided that the at least one thrust reversing flap forms an outer wall region of the outer housing and / or a radially outer inner wall region of the bypass duct in the flight position. This allows the at least one thrust reversing flap to be optimally integrated into the housing and to fulfill different functions depending on its position.Alternatively or additionally, it is provided that the at least one thrust reverser flap is pivotally connected to the outer casing. In other words, the thrust reverser flap can be moved between the flight and thrust reversal positions by pivoting about a rotation axis, which represents a structurally simple and robust way to change the position.

[0009] Further advantages arise from the fact that the at least one thrust reversing flap is arranged in the bypass duct in the thrust reversing position, in some areas, and / or that the at least one thrust reversing flap is arranged at least partially axially behind an outlet opening of the outlet nozzle in the thrust reversing position. This makes it particularly easy to apply the main and bypass flow to the thrust reversing flap simultaneously in the thrust reversing position.

[0010] In a further embodiment of the invention, particularly reliable and precise control or regulation of the position of the thrust reversing flap(s) is made possible in that the at least one thrust reversing flap can be moved between the thrust reversing position and the flight position by means of at least one actuator.

[0011] It has further proven advantageous if the at least one actuator comprises a telescopic rod and is designed to move the thrust reverser flap from the flight position to the thrust reversal position by extending the rod and / or to move the thrust reverser flap from the thrust reversal position to the flight position by retracting the rod. A telescopic rod, also referred to as a telescopic rod or telescopic bar, comprises two or more nested tubes or rods that can be extended and retracted relative to one another. This telescopic structure makes it possible to adjust the length of the rod as required, thereby enabling easy movement of the thrust reverser flap(s) between the thrust reversal position and the flight position. In addition, any intermediate positions can be precisely adjusted.

[0012] In a further embodiment of the invention, it has proven advantageous for the linkage to be arranged, in particular hinged, at one end on the thrust reverser flap and at the other end in the region of a radially inner wall of the bypass duct and / or downstream of the heat exchanger and / or within a heat exchanger casing. This allows the actuating device of the thrust reverser plate to be accommodated in the housing in a space-saving and aerodynamically favorable manner.

[0013] In a further advantageous embodiment of the invention, a central axis of the at least one thrust reverser flap is arranged in the thrust reverser position at an angle between 20° and 90°, in particular approximately 45°, relative to a rotational axis of a rotor of the gas turbine. In other words, the thrust reverser flap, or its central axis running lengthwise through the component, is arranged in the thrust reverser position at an angle to or at a right angle to the rotational axis of the rotor. This enables thrust reverser control or regulation as needed via the relative setting angle of the thrust reverser flap with respect to the rotational axis of the rotor.

[0014] In a further advantageous embodiment of the invention, it is provided that the at least one thrust reverser flap tapers in some regions in the axial direction. As a result, a plurality of thrust reverser flaps distributed over the circumference of the housing can be arranged in a ring-like manner in the thrust reversal position, so that their tapered end regions, which are arranged radially further inward in the thrust reversal position, are adapted to a correspondingly reduced diameter of the radially further inward bypass duct. Alternatively or additionally, it is provided that an inner wall of the thrust reverser flap is designed such that, in the flight position, the thrust reverser flap, together with an opposite, radially inner wall region of the bypass duct, forms a constriction of the bypass duct.This allows the thrust reverser to form a Venturi nozzle together with the casing in the flight position to control the flow and speed of the bypass stream.

[0015] Further advantages arise from the fact that several thrust reversers are spaced apart and distributed around the circumference of the casing and / or that each exhaust nozzle is assigned a thrust reverser. This enables particularly reliable and consistent thrust reversal.

[0016] In a further advantageous embodiment of the invention, the thrust reversing flaps, in the thrust reversing position, at least substantially completely close an outlet opening of the bypass duct. This allows the thrust reversing flaps to block the outlet of the bypass duct and thus redirect the entire bypass flow to the thrust reversal, thus enabling correspondingly effective thrust reversal.

[0017] Further features of the invention emerge from the claims, the figures and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures can be used not only in the respective combination specified, but also in other combinations without departing from the scope of the invention. Thus, embodiments are to be regarded as encompassed and disclosed by the invention that are not explicitly shown and explained in the figures, but which emerge and can be produced by separate combinations of features from the explained embodiments. Embodiments and combinations of features are also to be regarded as disclosed that therefore do not have all the features of an originally formulated independent claim.Furthermore, embodiments and combinations of features are to be considered disclosed, in particular by the embodiments presented above, which go beyond or deviate from the combinations of features presented in the claims. This shows: Fig. 1 is a perspective side view of a gas turbine for an aircraft according to the invention; Fig. 2 a schematic longitudinal section of an upper half of the gas turbine; Fig. 3 a schematic longitudinal section in the area of ​​an outer casing of the gas turbine with a thrust reverser flap in a flight position; Fig. 4 a schematic longitudinal section in the area of ​​the outer casing of the gas turbine with the thrust reverser flap in a thrust reversal position; Fig. 5 is a schematic and partially sectioned perspective view of the gas turbine viewed from the rear, with the thrust reversers in the flight position; and Fig. 6 is a schematic and partially sectioned perspective view of the gas turbine viewed from the rear, with the thrust reverser flaps in the thrust reversing position.

[0018] Fig. 1 shows a perspective side view of a gas turbine 10 according to the invention, in this case designed in a turbofan design, for an aircraft, in particular for an airplane. Fig. 1 will be discussed in conjunction with Fig. 2, which shows a schematic longitudinal section of an upper half of the gas turbine 10. The gas turbine 10 comprises a housing 12, which can also be referred to as a nacelle, with an inner housing 14, which has a main flow channel 16 for a main flow H, and with an outer housing 18, which has a secondary flow channel 20 for a secondary flow N. Furthermore, the gas turbine 10 comprises a water system 22, known per se, with a heat exchanger 24, through which the main flow H flows during operation of the gas turbine 10. Furthermore, the gas turbine 10 has a plurality of exhaust gas channels 26, through which the main flow H can be guided outwards from the main flow channel 16 through the heat exchanger 24 to respectively assigned outlet nozzles 28 of the housing 12.The outlet nozzles 28 are arranged uniformly distributed over the circumference of the housing 12 and have outlet openings 30 which, viewed in the axial direction of the gas turbine 10, are located upstream of an outlet opening 32 of the bypass duct 20. The course of an exhaust duct 26 is shown in . Fig. 2 is illustrated by way of example with a dashed line. It can be seen that the exhaust duct 26 is arranged in a region between an outlet of the main flow duct 16 and an outlet of the heat exchanger 24 in a crossflow with the bypass duct 20. The exhaust duct 26 is then arranged in a region downstream of the outlet of the heat exchanger 24 in the opposite direction to the main flow duct 16 and runs approximately as far as an axially forward fan stage 34 of the gas turbine 10. In a subsequent region, the exhaust duct 26 is deflected and runs in a final region up to the outlet nozzle 28 in at least substantially the same direction as the bypass duct 20.

[0019] The housing 12 has a plurality of thrust reversing flaps 36 which can be moved between a thrust reversing position ( Fig. 4), in which the thrust reversing flaps 36 can be acted upon by the main flow H and the secondary flow N and reverse the thrust of the gas turbine 10, and one in Fig. 1-3, in which the thrust reversing flaps 36 do not reverse the thrust of the gas turbine 10. The thrust reversing flaps 36 are spaced apart from one another and distributed over a circumference of the casing 12, with each outlet nozzle 28 being assigned a thrust reversing flap 36. In other embodiments, this 1:1 assignment may be deviated from, so that a different number of outlet nozzles 28 and thrust reversing flaps 36 may be used.

[0020] Fig. 3 shows a schematic longitudinal section through the outer casing 18 of the gas turbine 10 with a thrust reversing flap 36 in the flight position. It can be seen that the thrust reversing flap 36 is arranged upstream of the outlet opening 32 of the bypass duct 20 with respect to the bypass flow N, and that the thrust reversing flap 36 in the flight position forms an outer wall region of the outer casing 18 and a radially outer inner wall region of the bypass duct 20. With respect to the main flow H, the thrust reversing flap 36 is arranged axially behind or downstream of the outlet opening 30 of the respective associated outlet nozzle 28. The thrust reversing flap 36 can be moved between the thrust reversing position and the flight position by means of an actuator 38.For this purpose, the actuator 38 comprises a telescopic rod 40 and is designed to move the thrust reverser flap 36 from the flight position to the thrust reversal position by extending the rod 40 and to move the thrust reverser flap 36 from the thrust reversal position back to the flight position by retracting the rod 40. In addition, all intermediate positions can be adjusted. For this purpose, the thrust reverser flap 36 is pivotally connected to the outer housing 18 about a rotation axis D. The rod 40 is arranged at one end on the thrust reverser flap 36 and at the other end in the region of a radially inner wall of the bypass duct 20 downstream of the heat exchanger 24 and within a casing 42 of the heat exchanger 24. This represents a particularly space-saving and aerodynamically favorable arrangement.Furthermore, in the flight position, the thrust reverser flap 36, together with an opposite, radially inner wall region of the bypass duct 20, forms a constriction of the bypass duct 20, which functions as a type of Venturi nozzle.

[0021] Fig. 4 shows a schematic longitudinal section through the outer casing 18 of the gas turbine 10, with the thrust reversing flap 36 pivoted into the thrust reversing position. It can be seen that a central axis M of the thrust reversing flap 36 is arranged at an angle of approximately 45° relative to a rotational axis R of a rotor (not shown) of the gas turbine 10. The axial end region of the thrust reversing flap 36 abuts an inner wall of the bypass duct 20, thereby forming a stop and limiting the pivoting angle. The thrust reversing flap 36 is thus arranged with its axially rearward region in the bypass duct 20, completely blocking its outlet opening 32, and with its axially frontward region aligned axially behind the outlet opening 30 of the associated outlet nozzle 28. As a result, both the main flow H and the bypass flow N can be fully utilized and redirected for thrust reversal.This is indicated by corresponding arrows H and N, which are intended to schematically illustrate the flow conditions. If the thrust reverser flap 36 is pivoted into an intermediate position, a correspondingly smaller portion of the secondary flow N and, if applicable, the primary flow H can be used for thrust reversal. The individual thrust reverser flaps 36 can, in principle, be controlled or regulated jointly or individually.

[0022] Fig. Figure 5 shows a schematic and partially sectioned perspective view of the gas turbine 10 viewed from the rear, with the thrust reversers 36 in the flight position. For reasons of clarity, various features, in particular the exhaust nozzles 28, are not shown. Furthermore, only a portion of the outer casing 18 with three exemplary thrust reversers 36 is shown to allow a view into the rear portion of the bypass duct 20. Fig. 6 shows a schematic and partially sectioned perspective view of the Fig. 5, viewed from the rear, with the thrust reversing flaps 36 in the thrust reversing position. It can be seen that the thrust reversing flaps 36 taper in some areas in the axial direction, whereby they lie flush against one another in a ring-like manner in the thrust reversing position and thereby at least substantially completely close the outlet opening 32 of the bypass duct 20. List of reference symbols: 10 gas turbines 12 housings 14 inner casing 16 Main flow channel 18 outer casings 20 bypass channel 22 Water system 24 heat exchangers 26 exhaust duct 28 Outlet nozzle 30 Exit opening 34 Fan Level 36 Thrust reverser flap 38 Actuator 40 rods 42 cladding R rotation axis D axis of rotation H Main stream N bypass M central axis QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2020 / 187345 A1

[0002]

Claims

[1] Gas turbine (10) for an aircraft, comprising - a housing (12) with an inner housing (14) (12) which has a main flow channel (16) for a main flow (H), and an outer housing (18) (12) which has a secondary flow channel (20) for a secondary flow (N), - a water system (22) with a heat exchanger (24) which can be supplied with the main flow (H), and - at least one exhaust gas duct (26) through which the main flow (H) can be conducted from the main flow duct (16) through the heat exchanger (24) to at least one outlet nozzle (28) of the housing (12) to the outside, characterized byin that the housing (12) has at least one thrust reversing flap (36) which is movable between a thrust reversing position, in which the thrust reversing flap (36) can be acted upon by the main flow (H) and / or the secondary flow (N) in order to reverse a thrust of the gas turbine (10), and a flight position in which the thrust reversing flap (36) does not reverse the thrust of the gas turbine (10). [2] Gas turbine (10) according to claim 1, characterized by that the exhaust gas duct (26) is arranged in a region between an outlet of the main flow duct (16) and an outlet of the heat exchanger (24) in a cross-flow to the secondary flow duct (20) and / or that the exhaust gas duct (26) is arranged in a region downstream of the outlet of the heat exchanger (24) in the opposite direction to the main flow duct (16), is deflected in a subsequent region and runs at least substantially in the same direction to the secondary flow duct (20) in a final region up to the outlet nozzle (28). [3] Gas turbine (10) according to claim 1 or 2, characterized by that the at least one thrust reversing flap (36) is arranged upstream of an outlet opening (30) of the bypass duct (20) and / or that the at least one thrust reversing flap (36) forms an outer wall region of the outer casing (18) (12) and / or a radially outer inner wall region of the bypass duct (20) in the flight position and / or that the at least one thrust reversing flap (36) is pivotally articulated on the outer casing (18) (12). [4] Gas turbine (10) according to one of claims 1 to 3, characterized by that the at least one thrust reversing flap (36) is arranged in the thrust reversing position in some areas in the bypass duct (20) and / or that the at least one thrust reversing flap (36) is arranged in the thrust reversing position at least in some areas axially behind an outlet opening (30) of the outlet nozzle (28). [5] Gas turbine (10) according to one of claims 1 to 3, characterized byin that the at least one thrust reversing flap (36) is movable between the thrust reversing position and the flight position by means of at least one actuator (38), wherein the at least one actuator (38) preferably comprises a telescopic rod (40) and is designed to move the thrust reversing flap (36) from the flight position into the thrust reversing position by extending the rod (40), and / or to move the thrust reversing flap (36) from the thrust reversing position into the flight position by retracting the rod (40). [6] Gas turbine (10) according to claim 5, characterized by that the rod (40) is arranged, in particular articulated, at one end on the thrust reverser flap (36) and at the other end in the region of a radially inner wall of the bypass duct (20) and / or downstream of the heat exchanger (24) and / or within a casing (42) of the heat exchanger (24). [7] Gas turbine (10) according to one of claims 1 to 6, characterized bythat a central axis (M) of the at least one thrust reversing flap (36) is arranged in the thrust reversing position at an angle between 20 ° and 90 °, in particular of approximately 45 °, relative to a rotation axis (R) of a rotor of the gas turbine (10). [8] Gas turbine (10) according to one of claims 1 to 7, characterized by that the at least one thrust reversing flap (36) tapers in some regions in the axial direction and / or that an inner wall of the thrust reversing flap (36) is designed such that the thrust reversing flap (36) in the flight position, together with an opposite, radially inner wall region of the bypass duct (20), forms a constriction of the bypass duct (20). [9] Gas turbine (10) according to one of claims 1 to 8, characterized by that a plurality of thrust reversing flaps (36) are arranged spaced apart from one another over a circumference of the housing (12) and / or that each outlet nozzle (28) is assigned a thrust reversing flap (36). [10] Gas turbine (10) according to claim 9, characterized by that the thrust reversing flaps (36) in the thrust reversing position at least substantially completely close an outlet opening (30) of the bypass duct (20).

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