Blade for turbomachine

Abstract

This document relates to a blade wheel for a turbomachine, in particular for a fan without a fairing of the turbomachine, comprising at least one blade (204) comprising a plurality of cartridges (202-1, 202-2, 202-3) for generating gas capable of being triggered to crack said blade. Figure to be published with the abstract: [Fig. 3]

Description

Title of the invention: Blade for a turbomachine Technical field of the invention

[0001] The invention relates to the field of methods and systems for protecting blades, in particular blades for turbomachine fans, in particular for fans without fairings. State of the prior art

[0002] An example of an unducted engine, also called an “open rotor” in English, is shown in [Fig.l]. The engine 1 with an unducted propeller is attached to a support pylon 2 on the structure of an aircraft, which is not shown. The unducted nature of the propeller and rectifier assembly offers a much higher bypass ratio than current dual-flow engines. The engine 1 can be positioned, for example, either under a wing or against the tail cone of the aircraft fuselage. Upstream and downstream are understood here with respect to the general direction of the air flow F along the axis X of the engine. Said engine 1 comprises a power generator compartment 3 supplied with primary flow by an annular air inlet 4. The power generator compartment 3 drives an unducted propeller 5 placed upstream of the annular air inlet 4, comprising an annular row of moving blades 8.An annular row 6 of stator blades 9 is fixed to the casing 7 of the power generator compartment 3, downstream of the annular air inlet 4. This annular row 6 of stator blades 9 has the function of straightening the air flow F driven by the propeller 5, which passes around the casing 7 of said power generator compartment 3. The pylon 2 is fixed to the casing 7 of the power generator compartment 3, downstream of the annular row 6 of stator blades 9.

[0003] However, in the event of a movable blade 8 or a stator blade 9 breaking, the debris from said blade may impact another propulsion unit, the wing or the fuselage of the aircraft. Indeed, the absence of fairing around the movable blades 8 and the stator blades 9 does not allow the debris to be retained in the event of blade breakage as on turbomachines with fairings. To avoid damage to the aircraft, it is possible to shield the fuselage of the aircraft. However, this increases the mass of the aircraft and reduces the efficiency of the turbomachine.

[0004] The invention aims to remedy these drawbacks. Summary of the invention

[0005] To this end, the invention relates to a blade wheel for a turbomachine, in particular for a fan without a fairing of the turbomachine, comprising at least one blade, said blade comprising a plurality of gas generation cartridges capable of being triggered to crack said blade.

[0006] The cartridges make it possible to accelerate the rupture and ejection of debris from the weakened blades, particularly in a direction which will not impact the neighboring blades.

[0007] The blade can be made of a material that is sufficiently fissile with respect to the forces provided by the cartridges, in particular made of a weave of fibers embedded in a resin.

[0008] The blade wheel may comprise one or more detonators capable of triggering one or more of said gas generating cartridges.

[0009] Said detonators can be connected to the gas generation cartridges by electric cables or by remote wireless control, for example by wifi waves, Bluetooth © or other.

[0010] The cartridges may be arranged in clusters. For example, a cartridge may be independent of the clusters for specific needs in a particular area of ​​the blade.

[0011] The blade wheel may include multiple detonators, each detonator configured to trigger a cluster of gas generating cartridges.

[0012] Each group of cartridges may be connected by the same cable to one or more electric detonators. For example, a first cluster of cartridges may be located at a first lateral zone of the blade and a second cluster of cartridges may be located at a second lateral zone of the blade opposite the first lateral zone. The first lateral zone may extend along a leading edge of the blade and the second lateral zone may extend along a trailing edge of the blade. Furthermore, a third cluster of cartridges may be located at a third zone of the blade located radially outside the blade, in other words at the radially outer periphery of the blade. Thus, each cluster of cartridges may damage a targeted portion of the blade. Of course, the blade may comprise more or less than three clusters of cartridges.

[0013] Electrical cables or ignition systems may be integrated into the blade.

[0014] According to one embodiment, the gas generating cartridges may be explosive cartridges.

[0015] The cartridges may be of any type of cartridge capable of locally tearing the blade when triggered. For example, the cartridges may be cartridges of a type similar to airbag cartridges, in particular cartridges generating gas by explosion. Said airbag cartridges may be equipped with sensors to monitor the correct behavior of the blade.

[0016] The gas generation cartridges may be air and hydrogen mixture cartridges, the gas generation cartridges being supplied with air by an air flow passing through the turbomachine.

[0017] According to one embodiment, each blade may comprise the ge- cartridges gas generation.

[0018] Each blade can be made of carbon fibers embedded in a resin.

[0019] The invention also relates to a turbomachine comprising a fan without a fairing or blade wheel as mentioned above.

[0020] The invention also relates to a method for protecting a blade wheel as mentioned above, comprising the steps of:

[0021] - detect a crack in one or more blades of the blade wheel,

[0022] - triggering one or more gas generation cartridges of said blade detected.

[0023] The method may comprise the steps of:

[0024] - determining one or more blades to be removed from the blade wheel, in addition to the one or more blades detected, allowing to limit the unbalance of the blade wheel, and

[0025] - triggering one or more gas generation cartridges of said blade detected.

[0026] The method makes it possible to protect the external elements, such as the fuselage, of the aircraft carrying the blade wheel.

[0027] According to one embodiment, the cartridge charges can be triggered when the blades concerned enter a predetermined angular zone, between one twentieth and one fifth, in particular about one tenth, of the circle in which the blades of the blade wheel are inscribed. In particular, said predetermined angular zone can be configured so that when the blade is destroyed by the layers, its debris does not touch the aircraft or its environment.

[0028] The invention also relates to a method for protecting a turbomachine comprising a blade wheel as mentioned above, comprising the steps consisting of:

[0029] - detecting an overspeed of an element of said turbomachine,

[0030] - trigger one or more gas generating cartridges of one or more paddle wheel blades.

[0031] The overspeed detection step may concern the detection of overspeed of a low pressure shaft, a high pressure shaft, a high pressure turbine or a low pressure turbine of the turbomachine. The overspeed may be due to a mechanical problem on an element of the power generator, such as a shaft breakage, a loss of turbine blade, etc. These hazards would have harmful effects on the integrity of the turbomachine. Cracking of the blades of the blade wheel, in particular of the fan, by triggering the gas generation cartridges, makes it possible to limit the effects of such mechanical problems.

[0032] The method may comprise a step of determining the blade or blades to be removed by triggering the gas generation cartridges. The blade or blades to be removed may be chosen so as to reduce the speed of the turbomachine. Brief description of the figures

[0033] [Fig.l] the [Fig.l] already described represents an example of an aircraft engine without a fairing,

[0034] [Fig.2] [Fig.2] represents a blade equipped according to the invention for a tur- bomachine without fairing,

[0035] [Fig.3] [Fig.3] represents an example of a method for protecting a blade wheel of a turbomachine without fairing comprising a blade as represented in [Fig.2],

[0036] [Fig.4] [Fig.4] represents a front view of a blade wheel comprising a dawn as shown in [Fig.2],

[0037] [Fig.5] [Fig.5] represents an aircraft carrying the blade wheel of [Fig.4].

[0038] [Fig.6] [Fig.6] represents an example of a method of protecting a tur Machine without fairing comprising a blade wheel as shown in [Fig.4], Detailed description of the invention

[0039] [Fig. 2] shows a blade 204 made by weaving fibers, in particular carbon fibers embedded in a resin to solidify the fibers. The blade 204 comprises a plurality of cartridges 202-1, 202-2 and 202-3 embedded in the blade 204. The cartridges 202-1, 202-2 and 202-3 are arranged in clusters. Each group of cartridges 202-1, 202-2 and 202-3 is connected by the same cable 206-1, 206-2 and 206-3, respectively, to an electric detonator. The cartridges 202-1 are arranged at a first lateral zone 208-1 of the blade 204 and the cartridges 202-3 are arranged at a second lateral zone 208-3 of the blade 204 opposite the first lateral zone 208-2. The cartridges 202-2 are arranged at a third zone 208-2 located radially outside the blade 204.

[0040] Thus, each group of cartridges 202-1, 202-2 and 202-3 can damage a targeted part of the blade 204. Of course, the blade can comprise more or less than three groups of cartridges 202.

[0041] The cartridges 202-1, 202-2 and 202-3 may be of any type of cartridge capable of locally tearing the blade 204 when they are triggered. For example, the cartridges 202-1, 202-2 and 202-3 may be cartridges of a type similar to airbag cartridges, in particular cartridges generating gas by explosion. The airbag type capsules may be equipped with sensors to monitor the correct behavior of the blade. The cartridges 202-1, 202-2 and 202-3 may be cartridges generating gas from a mixture of air and hydrogen. In this case, the air may come from an air stream of the turbomachine comprising the blade.

[0042] In addition, the cartridges 202-1, 202-2 and 202-3 or capsule and can be equipped with sensors to monitor the behavior of the blade and its state of wear.

[0043] With reference to [Fig. 3], the method 100 is configured to protect the external elements, and mainly the fuselage, of an aircraft equipped with a turbomachine without fairing, in particular comprising a fan, or blade wheel 300, without fairing such as that shown in [Fig. 4] comprising blades such as the blade 204 of [Fig. 2]. For this, the method 100 comprises a first step 102 of detecting the start of a crack A, or crack, or a crack in one of the blades of the fan 300, for example the blade 204-1. The method 100 then comprises a step 104 of triggering the cartridges 202-1, 202-2 and 202-3 of said blade 204-1. For example, the cartridges can be triggered sequentially in groups, in other words by triggering the cartridges located in the zone 208-1, then those in the zone 208-2, then those in the zone 208-3. The triggering order can be reversed.Additionally, cartridges from two zones can be fired together. In addition, all cartridges can be fired simultaneously.

[0044] The elimination of blade 204-1 unbalances the fan and causes an imbalance which can be dangerous for the aircraft.

[0045] To limit the impact of this phenomenon, the method 100 comprises a step 106 of determining one or more blades 204-2 complementary in inertia to said blade 204-1 detected in step 102 and making it possible to reduce the unbalance produced by the softening of the blade detected in step 102 or its ejection.

[0046] Then, the cartridges 202-1, 202-2 and 202-3 of the blades 204-2 are triggered to eliminate said blades from the fan and reduce the unbalance caused by step 104. This makes it possible to operate the turbomachine in degraded mode allowing the aircraft to land safely.

[0047] With reference to [Fig. 5], an aircraft 10 is equipped with at least one turbomachine itself equipped with the blade wheel 300 of [Fig. 4] and comprises means for implementing the method 100 of [Fig. 3]. To prevent the debris from the blade 204-1 or the blades 204-2 from striking the fuselage of the aircraft 10, steps 104 and 108 are carried out when the blades 204-1 and 204-2 enter the angular zone C1 of the circle in which the blades 204 are inscribed. Thus, the explosive charges of the cartridges 202-1, 202-2 and 202-3 are triggered each time it passes through the angular zone C1 so that the debris does not touch the aircraft 10 or its environment until it has regained natural speed. Thus, the debris will be ejected into the angular zone C2. The angular zones Cl and C2 represent a quarter of the said circle, particularly arranged in the upper part of the turbomachine. The angular zone Cl represents a third of this quarter of the circle.In particular, the angular zone C1 is arranged downstream of the angular zone C2 following the direction of rotation of the blades 204. It is preferable to avoid triggering the cartridges 202 when the blade is in the zone. remaining angular C3.

[0048] The method 400 of [Fig. 6] aims to protect a turbomachine, similar to the turbomachine 1, comprising the blade wheel 300 in the event of a mechanical problem on an element of the power generator 3, such as a shaft breakage, a loss of turbine blade, etc. The method 400 comprises:

[0049] - a step 402 for detecting an overspeed of an element of said turbomachine,

[0050] - a step 404 of determining one or more blades to be removed from the blade wheel

[0051] - a step 406 for triggering one or more gas generation cartridges in the blade(s) determined in the previous step 204.

[0052] The overspeed detection step may relate to the detection of overspeed of a low pressure shaft, a high pressure shaft, a high pressure turbine or a low pressure turbine of the turbomachine.

[0053] In step 404, the blades to be removed are determined so as to reduce the speed of the turbomachine.

Claims

Claims

1. Blade wheel (300) for a turbomachine, in particular for a fan without a fairing of the turbomachine, comprising at least one blade (204), said blade comprising a plurality of cartridges (202-1, 202-2, 202-3) for generating gas capable of being triggered to crack said blade.

2. A blade wheel (300) according to the preceding claim, comprising one or more detonators capable of triggering one or more of said gas generating cartridges.

3. A blade wheel according to the preceding claim, comprising a plurality of detonators, each detonator being configured to trigger a cluster of gas-generating cartridges (202-1, 202-2, 202-3).

4. A blade wheel according to any preceding claim, wherein the gas generating cartridges (202-1, 202-2, 202-3) are explosive cartridges.

5. Blade wheel according to one of claims 1 to 3, in which the gas generation cartridges (202-1, 202-2, 202-3) are cartridges with a mixture of air and hydrogen, the gas generation cartridges being supplied with air by an air flow passing through the turbomachine.

6. A blade wheel (300) according to any preceding claim, wherein each blade (204) is made of carbon fibers embedded in a resin.

7. Turbomachine comprising a blade wheel (300) according to one of the preceding claims.

8. Method for protecting a blade wheel according to one of claims 1 to 6, comprising the steps of: - detecting (102) a crack in one or more blades of the blade wheel, - triggering (104) one or more gas generation cartridges of said detected blade.

9. Method according to the preceding claim, comprising the steps of: - determining (106) one or more blades to be removed from the blade wheel, in addition to the detected blade(s), making it possible to limit the unbalance of the blade wheel, and - triggering (108) one or more gas generation cartridges said dawn detected.

10. Method (400) for protecting a turbomachine comprising a blade wheel according to one of claims 1 to 6, comprising the steps of: - detect (402) an overspeed of an element of said turbomachine, - trigger (404) one or more gas generation cartridges of one or more blades of the blade wheel.

Images