Aircraft turbine engine comprising a system for intercepting foreign bodies and capture method

Abstract

The invention relates to a gas turbine engine (1) for aircraft, comprising a system (5) for intercepting at least one foreign body, the system being mounted in an inner zone (Z1), the interception system (5) comprising: a blind recess (51) which is formed in an inner wall (41) of a casing (4) externally delimiting the inner zone (Z1) and is intended to receive the foreign body; an access door (52) to the blind recess (51), the access door being configured to move between a closed position (P0) in which it partly forms the inner wall (41), and an open position; and a mechanical connection member (53) which connects the access door (52) to the casing (4) and is configured to hold the access door (52) by default in the closed position (P0) and, additionally, to open the access door (52) into the open position following the application of a force by the foreign body on the access door (52).

Description

Aircraft turbomachine comprising a foreign body interception system and capture method

[0001] The present invention relates to the field of aircraft turbomachinery and more particularly to a system for protecting a turbomachine against foreign bodies such as birds.

[0002] As is known, an aircraft includes one or more turbomachines to enable its movement by accelerating an airflow from upstream to downstream. To this end, the turbomachine 1 includes a propulsion unit 2 mounted on a drive shaft, which converts the rotational motion into an airflow F that propels the aircraft.

[0003] To drive the rotation of the propulsion unit 2, the turbomachine 1 comprises, successively along a turbomachine axis X, at least one compressor 11, one combustion chamber 12, and at least one turbine 13. The compressor 11 is configured to receive an incoming airflow, corresponding in this example to a portion of the airflow from the propulsion unit 2, and compress it to supply the combustion chamber 12. The combustion, in the combustion chamber 12, between a fuel flow and the compressed air flow generates an exhaust airflow that drives the turbine 13 in rotation, causing the rotation of the drive shaft. The latter, in turn, drives the compressor 11 and the propulsion unit 2.

[0004] In the case of a three-flow turbomachine (as shown in the figure), the compressor 11, the combustion chamber 12, and the turbine 13 form a primary zone Zp for the circulation of a primary airflow Fp, also called the primary stream. The primary zone Zp is externally delimited by a first casing C1. The turbomachine 1 also includes a secondary zone Zs for the circulation of a secondary airflow Fs accelerated by the propulsion unit 2. The secondary zone Zs is not externally delimited by a casing. The secondary zone Zs is internally delimited only by a second casing C2, commonly referred to as the intermediate casing.

[0005] In practice, the turbomachine 1 comprises an inlet zone Ze, also called the inlet stream, which is divided into the primary zone Zp and a tertiary zone Zt, also called the tertiary stream. The tertiary zone Zt is positioned between the primary zone Zp and the secondary zone Zs, as illustrated in Figure 1. The tertiary zone Zt is delimited internally by the first casing C1 and externally by the second casing C2. As illustrated in Figure 1, downstream of the propulsion unit 2, the second casing C2 externally delimits the inlet zone Ze and then the tertiary zone Zt.

[0006] The airflow F generated by the propulsion unit 2 is initially divided into an inlet airflow Fe circulating in the inlet zone Ze and an external secondary airflow Fs circulating in the secondary zone Zs. The inlet airflow Fe then divides into a primary airflow Fp circulating in the primary zone Zp to be consumed in the combustion chamber 12, and a tertiary airflow Ft circulating in the tertiary zone Zt to perform various functions such as cooling heat exchangers, propulsion, etc.

[0007] When the aircraft is in flight, foreign bodies, such as birds, can be sucked into the propulsion unit 2 and enter the inlet zone Ze, causing damage to the turbomachine.

[0008] In practice, in a turbofan engine of the turbojet type, foreign bodies are most often crushed by the propulsion unit 2, which has a high speed, and the debris is evacuated through an evacuation channel, positioned in the primary zone Zp within the compressor 11 and opening into the secondary zone Zs.

[0009] We also know from document EP 3913231A1 of a turbofan aircraft turbomachine, a close-up view of which is shown in Figure 1. This turbomachine comprises a plurality of grooves 101 formed in the intermediate casing and opening into the primary zone Zp upstream of the compressor. The primary zone Zp has a diameter that decreases with the direction of airflow from upstream to downstream, forming a narrowing region known as the "gooseneck." The grooves 101 are formed in the gooseneck and act as a trap for debris. The debris becomes lodged in the grooves 101 and cannot flow further downstream in the primary zone Zp.

[0010] However, the grooves in document EP 3913231A1 do not allow for the capture of large debris. Therefore, there is a risk that foreign objects, such as whole birds, could circulate in the primary zone Zp and reach the compressor, potentially damaging the turbomachine 1.

[0011] To overcome this drawback, it is known to oversize the turbomachine components, particularly the compressor blades, which leads to an increase in the dimensions of the intermediate casing and therefore its mass. A significant mass results in increased stress on the bearings, as well as increased fuel consumption for the aircraft and consequently its greenhouse gas emissions. Furthermore, oversizing the gas turbomachine does not guarantee complete elimination of the risk of combustion chamber failure should the turbomachine ingest an excessive volume of foreign matter.

[0012] In the case of a triple-flow turbomachine, the propulsion unit, as is known, has a large circumference and a limited number of blades. Such a propulsion unit therefore rotates at reduced speeds to avoid reaching sonic velocities at the blade tips. Consequently, in a triple-flow turbomachine, the low rotational speeds of the propulsion unit do not allow for the satisfactory grinding of foreign bodies before they enter the turbomachine's inlet zone, thus exacerbating the aforementioned drawbacks.

[0013] The invention aims to eliminate at least some of these drawbacks by providing a reliable and efficient aircraft turbomachine that eliminates any risk of foreign body ingestion. The invention specifically relates to a turbomachine comprising such a foreign body interception system with a limited size and mass. The invention is particularly relevant to triple-flow turbomachines for minimizing the risk of damage.

[0014] Incidentally, US2015314883A1 and US4713934A documents describe aircraft engines with a foreign object capture or evacuation device. However, neither US2015314883A1 nor US4713934A describes a device for capturing multiple foreign objects in a blind housing. PRESENTATION OF THE INVENTION

[0015] The invention relates to an aircraft gas turbomachine comprising a casing delimiting an internal circulation zone of a first airflow and an external circulation zone of a second airflow, the casing comprising a radially internal wall, externally delimiting the internal zone, and a radially external wall, internally delimiting the external zone, the gas turbomachine comprising at least one compressor, one combustion chamber and at least one turbine, the first airflow circulating from an upstream to a downstream along a turbomachine axis in the internal zone at least to supply the combustion chamber, the interceptor system is mounted in the internal zone upstream of the compressor.The gas turbomachine is remarkable in that it includes at least one foreign body interception system comprising: a blind housing formed in the inner wall of the casing, the blind housing including a storage portion intended to receive the foreign body, an access door to the blind housing, the access door being configured to move between: a closed position in which it forms part of the inner wall of the casing, and an open position in which the inner wall of the casing is discontinuous, allowing access to the blind housing, a mechanical linking element, connecting the access door to the casing, configured, on the one hand, to maintain the access door by default in the closed position and, on the other hand, to open the access door in the open position following the application of a force by the foreign body on the access door.

[0016] The interception system according to the invention allows for the capture of foreign bodies without affecting the aerodynamics of the internal area or the performance of the turbomachine. The access door allows the blind housing to be closed by integrating with the inner wall of the casing. Thus, when the access door is in the closed position, the initial airflow circulates normally within the internal area, similar to a turbomachine without an interception system. Therefore, the turbomachine incorporates a foreign body interception system while ensuring optimal efficiency for aircraft propulsion.

[0017] The mechanical linkage, configured to maintain the access door in the closed position by default, ensures this position in case of failure, for example. Optimal operation of the turbomachine is thus advantageously guaranteed without any intervention on the interception system. The access door remains closed when small foreign objects are ingested, as these objects are not large enough to open the access door.

[0018] Similarly, a simple force from the impact of a foreign object is sufficient to open the access door, which is similar to a hatch or a swinging door, of the "Western" type. Furthermore, the force exerted by the foreign object, projected onto the access door due to the aircraft's speed, is sufficient to allow access to the blind compartment, and the mechanical mechanism allows the access door to return to the closed position, automatically closing the compartment after the foreign object is captured. Therefore, the pilot or an operator does not need to perform any maneuver to open or close the access door, and the foreign object is automatically trapped in the blind compartment as soon as it enters the interior zone.

[0019] Thus, even after the foreign object is captured, the inner wall of the housing remains intact, allowing the initial airflow to circulate within the internal area. The foreign object is intercepted and poses no risk of damage to the turbomachine.

[0020] Positioning the compressor upstream ensures that no foreign matter affects compression performance, guaranteeing optimal turbomachine efficiency.

[0021] Preferably, in a gas turbomachine comprising, along the turbomachine axis, a low-pressure compressor and a high-pressure compressor, the interceptor system is mounted in the internal zone upstream of the compressors. Preferably, the interceptor system is mounted in the internal zone between the propulsion unit and the low-pressure compressor, thus ensuring that compressor performance is not affected.

[0022] Preferably, the internal zone takes the form of an internal channel including a constriction portion. The interception system is mounted within this constriction portion. The term "constriction portion" refers to an internal zone with a diameter that decreases from an air inlet. This constriction portion gives the internal channel an appearance closer to the engine axis and is known to those skilled in the art as a "gooseneck." Such a gooseneck has a curvature and a point of inflection that directs the airflow toward the compressor while allowing a foreign object, whose mass generates greater inertia, to be projected against the inner wall of the housing.The access door, located in the narrowing of the inner wall, is optimally positioned so that any foreign object projected against the inner wall will strike the access door, generating sufficient force to open it and trap the object within the blind opening. The access door thus forms a natural barrier against foreign objects in the interior zone, as it extends partially perpendicular to the incoming airflow.

[0023] In one embodiment, the gas turbomachine is free of a discharge valve upstream of the compressor, the discharge valve being configured to create a circulation channel for a discharge airflow from the inner area to the outer area.

[0024] Preferably, the mechanical linkage is a passive component. This eliminates the risk of failure in the interception system, ensuring the capture of any foreign object present downstream of the propulsion unit. Indeed, with a passive component, it is not necessary, for example, to use an electrical power supply to activate the access door in an open or closed position. This eliminates the risk of power failure. The passive mechanical linkage ensures that the access door remains closed by default, thus guaranteeing optimal circulation of the initial airflow in the interior zone under all circumstances.

[0025] In one embodiment, the mechanical linkage includes a spring. This spring allows the access door to be easily connected to the housing, ensuring that the access door remains in its default closed position. Furthermore, it is easy to adapt the spring to provide a desired torque (or tension) to achieve a compromise between sufficient torque to keep the access door closed despite aerodynamic forces exerted against it by the initial airflow entering the interior, and a torque lower than the impact force of a foreign object, thus ensuring the access door opens in the event of an impact. The spring torque or tension can therefore be adapted to the mass of the foreign object intended to be housed within the sealed compartment.

[0026] Preferably, the spring is a helical spring having a spring torque, the spring torque is between 1000 and 3000 Nm. Such a torque is advantageously greater than the aerodynamic forces applied by the first airflow in the inner area on the inner wall of the casing while being less than the force produced by the impact of a foreign body, for example a bird.

[0027] In one embodiment, in the closed position, the access door forms a continuous aerodynamic surface with the inner wall of the casing, ensuring that the turbomachine including the interception system maintains optimal performance.

[0028] In one embodiment, the blind housing has an annular shape which thus extends over the entire circumference of the inner wall of the casing.

[0029] Alternatively, the interception system comprises a plurality of blind housings distributed around the circumference of the inner wall of the housing. Preferably, the housing having a plurality of structural connecting arms extending radially inward from the housing, the interception system comprises a plurality of blind housings, each blind housing being formed between two structural arms, so as to ensure the interception of a foreign body regardless of its angular position.

[0030] In one embodiment, the storage portion includes a foreign body storage capacity greater than 1L, preferably greater than 3L. This allows for the storage of a significant volume of foreign bodies, for example, an entire bird that has not been crushed during its passage through the propulsion organ, unlike prior art systems which are intended for the storage of debris.

[0031] In one embodiment, the storage portion has a storage height, defined radially with respect to the turbomachine axis, of between 80 and 220 mm. Such a height allows the capture of large foreign bodies, such as whole birds, unlike prior art systems which only allow the capture of debris.

[0032] According to a preferred design, the storage portion has a storage length, defined along the turbomachine axis, of between 1 and 1.5 times the storage height. Such a length allows for sufficient storage space to hold several foreign objects without obstructing the opening of the access door.

[0033] In one embodiment, the interception system includes a device for detecting instances of the access door being opened. Such a detection device informs the pilot of the capture of one or more foreign objects. In particular, it allows for the detection of a high frequency of occurrences, indicating a significant number of intercepted foreign objects. This enables a cleanup operation to be scheduled only when necessary.

[0034] Preferably, the interception system includes a device for measuring the mass of foreign bodies present in the blind housing. Such a measuring device advantageously allows for the detection of a significant number of foreign bodies captured in the blind housing. This makes it possible to schedule maintenance to empty the blind housing and prepare it, for example, for a future flight. The measuring device thus ensures the subsequent capture of any foreign body.

[0035] The invention also relates to a method of capturing a foreign body in a gas turbomachine as described above, by means of the interception system, the mechanical linking member initially maintaining by default the access door in the closed position, the method comprises the steps of: applying a force, by the foreign body, on the access door, and moving the access door into the open position, the foreign body being stored in the storage portion of the blind housing.

[0036] In one embodiment, the capture method subsequently includes a step of automatically moving the access door into the closed position following the cessation of the application of force by the foreign body on the access door.

[0037] The invention also relates to a gas turbomachine for aircraft comprising: a first casing delimiting an internal zone for the circulation of an internal airflow and a secondary zone for the circulation of a secondary airflow, and a second casing mounted in the internal zone and delimiting, in the internal zone, a primary zone for the circulation of a primary airflow and a tertiary zone for the circulation of a tertiary airflow, the primary airflow being configured to supply a combustion chamber of the turbomachine, the internal airflow being divided, in the internal zone, between the primary airflow and the tertiary airflow, the first casing comprising a radially internal wall, externally delimiting the internal zone, and a radially external wall, internally delimiting the secondary zone.

[0038] The gas turbomachine is remarkable in that it includes a system for intercepting at least one foreign body comprising: a blind housing formed in the inner wall of the first casing, the blind housing including a storage portion intended to receive the foreign body, an access door to the blind housing, the access door being configured to move between: a closed position in which it forms part of the inner wall of the first casing, and an open position in which the inner wall of the first casing is discontinuous, allowing access to the blind housing, a mechanical linking element, connecting the access door to the casing, configured, on the one hand, to maintain by default the access door in the closed position and, on the other hand, to open the access door in the open position following the application of a force by the foreign body on the access door. PRESENTATION OF THE FIGURES

[0039] The invention will be better understood upon reading the following description, given by way of example, and referring to the following figures, given by way of non-limiting examples, in which identical references are given to similar objects.

[0040] This is a schematic representation of an aircraft turbomachine.

[0041] This is a schematic representation of a turbomachine inlet according to the prior art.

[0042] Laest is a schematic representation of an aircraft turbomachine according to an embodiment of the invention comprising a foreign body interception system.

[0043] This is a close-up view of the interception system in a closed position.

[0044] This is a schematic representation of the interception system for a foreign body.

[0045] Laest is a schematic representation of the interception system in an open position during the interception of a foreign body.

[0046] This is a schematic representation of the interception system after the interception of a foreign body.

[0047] It should be noted that the figures explain the invention in detail for implementing the invention, said figures being of course able to serve to better define the invention where appropriate. DETAILED DESCRIPTION OF THE INVENTION

[0048] Figure 1 shows a turbomachine designed to be mounted in an aircraft to enable its movement by accelerating an airflow from upstream to downstream. In this example, the turbomachine 1 extends longitudinally along a turbomachine axis X. In other words, the airflow circulates within the turbomachine 1 from upstream to downstream along the turbomachine axis X. To achieve this, the turbomachine 1 includes a propulsion unit 2, mounted on a drive shaft, which converts the rotational motion into an airflow F that propels the aircraft. This document describes an example of a turbomachine in which the incoming airflow is axisymmetric. It is understood that the air intake in the turbomachine could alternatively be axisymmetric, such as the air intake of a military engine, for example, a TP400-type turboprop.

[0049] To drive the rotation of the propulsion unit 2, the turbomachine 1 comprises successively along the turbomachine axis X, one or more compressor(s) 11, a combustion chamber 12 and one or more turbine(s) 13. It goes without saying that the turbomachine 1 could comprise several propulsion shafts.

[0050] In practice, in this example, the turbomachine 1 comprises, successively along the turbomachine axis X, a low-pressure compressor, a high-pressure compressor, a combustion chamber 12, a high-pressure turbine, and a low-pressure turbine. For the sake of brevity, the term "compressor 11" hereafter refers to the combination of the two compressors, low-pressure and high-pressure, in the case of such a gas turbomachine 1. Upstream positioning of compressor 11 thus refers to positioning the first compressor upstream along the turbomachine axis X, that is, the compressor mounted directly downstream of the propulsion unit 2.

[0051] The compressor 11 is configured to receive an incoming airflow, corresponding in this example to a portion of the airflow from the propulsion unit 2, and compress it to supply the combustion chamber 12. The combustion in the combustion chamber 12, between a fuel flow and the compressed air flow, generates an exhaust airflow that drives the turbine 13 in rotation, which in turn drives the propulsion shaft. The latter, in turn, drives the compressor 11 and the propulsion unit 2.

[0052] In practice, and still referring to the diagram, the turbomachine 1 comprises, downstream of the propulsion unit 2, at least one internal zone Z1 and an external zone Z2 delimited by a casing 4 for the circulation of two distinct airflows. In other words, downstream of the propulsion unit 2, the airflow F is divided into a first airflow F1, which circulates in the internal zone Z1 and supplies at least part of the combustion chamber 12, and a second airflow F2 which circulates in the external zone Z2 and contributes to the propulsion of the aircraft.

[0053] In a known dual-flow turbomachine 1 (not shown), the compressor 11, combustion chamber 12, and turbine 13 form a primary zone for the circulation of a primary airflow, also called the primary stream. The turbomachine 1 also includes a secondary zone for the circulation of a secondary airflow accelerated by the propulsion unit 2, also called the secondary stream when it is externally delimited by a casing. The primary and secondary zones are annular and extend radially around the drive shaft, with the secondary zone extending radially outward from the primary zone around the casing 4. In other words, in this embodiment, the inner zone Z1 corresponds to the primary zone (the first airflow F1 corresponding to the primary airflow that feeds the combustion chamber 12), and the outer zone Z2 corresponds to the secondary zone (the second airflow F2 corresponding to the secondary airflow).

[0054] In a triple-flow turbomachine 1, as shown in the figure, the turbine comprises, directly downstream of the propulsion unit 2, a primary casing that delimits an inlet zone, also called the inlet stream, through which an inlet flow circulates, and a secondary zone, which extends radially outward from the inlet zone and through which a secondary air flow circulates. The secondary zone is not externally delimited by a casing. The secondary zone is delimited only internally. The inlet zone is divided into a primary zone and a tertiary zone, also called the tertiary stream. The tertiary zone extends radially between the primary and secondary zones. Analogously to a dual-flow turbomachine, the compressor 11, the combustion chamber 12, and the turbine 13 form the primary zone through which a primary air flow circulates.Also, downstream of the propulsion unit 2, the inlet airflow is divided into a primary airflow that circulates in the primary zone to supply the combustion chamber 12 and a tertiary airflow that circulates in the tertiary zone. In other words, in this embodiment, the inner zone Z1 preferably corresponds to the inlet zone (the first airflow F1 corresponding to the inlet airflow which is subsequently divided into the primary airflow and the tertiary airflow), and the outer zone Z2 corresponds to the secondary zone (the second airflow F2 corresponding to the secondary airflow).

[0055] In this example, the turbomachine 1 is unfaired, meaning it lacks an external nacelle. In other words, the external area (here, the secondary area) is open to the outside. It goes without saying that the invention also applies to a different type of turbomachine, for example, a ducted turbomachine such as a turbojet engine.

[0056] As described previously, the housing 4 is mounted between the inner zone Z1 and the outer zone Z2. More specifically, with reference to the diagram, the housing 4 comprises a radially inner wall 41, which externally delimits the inner zone Z1, and a radially outer wall 42, which internally delimits the outer zone Z2.

[0057] Preferably, the intermediate casing 4 is made of a metallic alloy material, enabling a lightweight and robust turbomachine 1. It goes without saying that the intermediate casing 4 could alternatively be made of a composite material, for example, an organic matrix composite.

[0058] In this example, the inner zone Z1 includes a narrowing portion 15, shown in Figures 3 and 4. Preferably, the narrowing portion 15 is positioned within the inner zone Z1 between a plurality of stator blades 16 (shown in Figure 1), which straighten the first airflow F1 entering the inner zone Z1. In practice, the diameter of the inner zone Z1 in the narrowing portion 15 decreases from upstream to downstream. Such a narrowing portion 15 is known to those skilled in the art as a "gooseneck".

[0059] Preferably, the turbomachine 1 is free of a discharge valve in the inner zone Z1 upstream of the compressor 11. As is known, such a discharge valve is configured to transfer a portion of the first airflow F1 to the outer zone Z2 to adjust the flow rate of each airflow before it enters the compressor 11. It is understood that the turbomachine 1 according to the invention could include such a discharge valve. Preferably, in the embodiment in which the turbomachine 1 is a dual-flow turbomachine, it is free of a discharge valve upstream of the compressor 11, configured to create a circulation channel for a discharge airflow from the inner zone Z1 (primary zone) to the outer zone Z2 (secondary zone) upstream of the compressor 11 in order to adjust the dilution ratio and limit the pumping effect.

[0060] With further reference to figures 3 and 4, the turbomachine 1 according to the invention includes one or more interception system(s) 5 of one (or more) foreign body(ies) CO, for example a bird.

[0061] According to one aspect of the invention, the interception system 5 is mounted in the internal zone Z1. Preferably, the interception system 5 is mounted upstream of the compressor 11. More precisely, the interception system 5 is preferably mounted at the inlet of the internal zone Z1, in the constriction portion 15. In other words, the interception system 5 is preferably mounted between the propulsion unit 2 and the compressor 11. That is to say, in the case of a turbomachine comprising several compressors 11, the interception system 5 is preferably mounted directly downstream of the propulsion unit 2, i.e., between the propulsion unit 2 and the first compressor 11. Such positioning allows for optimal capture of a foreign body CO carried by a first airflow F1 entering the internal zone Z1 in a longitudinal direction from upstream to downstream, as will be described in more detail later.

[0062] In one embodiment, the turbomachine 1 comprises a plurality of interceptor systems 5 distributed annularly within the casing 4 around the inner zone Z1. In particular, in the case of a triple-flow turbomachine 1, it comprises a plurality of structural arms extending radially and connecting the casing 4 to the rest of the turbomachine 1, the plurality of structural arms being distributed circumferentially in a homogeneous manner. An interceptor system 5 extends, preferably, between each pair of two adjacent structural arms. Alternatively, the turbomachine 1 comprises a single annular interceptor system 5, extending circumferentially throughout the casing 4 at the periphery of the inner zone Z1.

[0063] Figure 1 represents a close-up view of an interception system 5 according to one embodiment of the invention. More precisely, Figure 1 represents a view in a longitudinal section plane (X, Z). In this example, for clarity, in the section plane (X, Z), the Z axis, orthogonal to the turbomachine axis X, extends vertically.

[0064] According to one aspect of the invention, the interception system 5 comprises a blind housing 51 formed in the housing 4, an access door 52 to the blind housing 51 and a mechanical linking member 53 which connects the access door 52 to the housing 4.

[0065] More specifically, the blind housing 51 is formed in the inner wall 41 of the housing 4, meaning that it is open towards the inner zone Z1. The blind housing 51 is designed to receive the foreign body CO. In this example, with reference to the diagram, the blind housing 51 defines an opening in the inner wall 41 whose upstream and downstream ends are separated by a length L51 between 100 mm and 350 mm, allowing the passage of foreign bodies CO larger than debris.

[0066] In a preferred embodiment, the blind housing 51 has a substantially elongated shape downstream along the turbomachine axis X, as shown in the figure. In other words, the blind housing 51 forms substantially a pocket opposite the opening in the inner wall 41, so as to allow the retention of foreign bodies CO once they have been captured.

[0067] In practice, in this example, the blind housing 51 comprises, substantially successively from upstream to downstream, a portion of clearance 51A of the access door 52 and a portion of storage 51B for the storage of foreign bodies CO.

[0068] The travel portion 51A preferably has a length along the turbomachine axis X substantially equal to a length of the access door 52, to allow the latter to open and close without the CO foreign body(ies) stored in the storage portion 51B hindering this movement. In practice, since the access door 52 is preferably a hinged door, as will be described in more detail later, the dimension of the travel portion 51A is preferably substantially equal to a length of the access door 52, which corresponds to a radius from the upstream end of the opening defined in the inner wall 41 and described previously.

[0069] The storage portion 51B extends along the turbomachine axis X downstream of the travel portion 51A and is configured to retain captured CO foreign bodies. Representing a longitudinal cross-sectional view of the blind housing 51, the latter extends longitudinally along the turbomachine axis X and, in this example, vertically along a vertical axis Z, orthogonal to the turbomachine axis X, defining a cross-sectional plane (X, Z). In the cross-sectional plane (X, Z), the storage portion 51B preferably has a storage height H51B along the vertical axis Z greater than 80 mm to allow the storage of CO foreign bodies larger than debris. Preferably, the storage height H51B of the storage portion 51B is less than 220 mm, preferably less than 140 mm, in order to limit the radial volume of the blind housing 51.

[0070] Similarly, in a preferred embodiment, the storage portion 51B has a storage length L51B defined along the turbomachine axis X, which is between 1 and 1.5 times the storage height H51B of the previously defined storage portion 51B. Preferably, the storage length L51B is between 80 and 330 mm. In this example, the storage length L51B is between 100 and 150 mm. In practice, preferably, the storage portion 51B includes a CO foreign body storage capacity greater than 1 L, preferably even greater than 3 L. The storage portion 51B is thus dimensioned to allow the ingestion of large CO foreign bodies, such as several whole birds, while ensuring that the mechanical strength of the intermediate housing 4 is not compromised.The dimensions of storage area 51B also allow such storage without hindering the opening and closing of access door 52.

[0071] With further reference to the, the access door 52 allows access to the blind housing 51. More precisely, the access door 52 is configured to move between a closed position P0 (represented on the), in which it forms part of the inner wall 41 of the housing 4, and an open position P1 (represented on the), in which the inner wall 41 of the housing 4 is discontinuous, allowing access to the inside of the blind housing 51.

[0072] Preferably, the access door 52, in the closed position P0, forms a continuous surface with the inner wall 41 of the housing 4, so as to avoid any disturbance of the first flow F1 in the inner zone Z1, despite the formation of the blind recess 51 in the housing 4. For this purpose, the access door 52 preferably has an elongated and concave shape to complement the inner wall 41 of the housing 4 in the narrowing portion 15 at the level of the blind recess 51. In other words, the access door 52 preferably has an aerodynamic shape that complements the inner wall 41 of the housing 4 at the level of the blind recess 51.

[0073] In practice, the access door 52 has a length L52 (shown in the figure), defined along the axis connecting the two ends of the opening of the blind housing 51. Preferably, the length L52 of the access door 52 is substantially similar to the length L51 of the opening formed by the blind housing 51 in the inner wall 41. This ensures the continuity of the inner wall 41 of the housing 4 when the access door 52 is in the closed position P0.

[0074] In this example, access door 52 is made of a composite material, for example, an organic matrix material, so as to form a mechanically strong access door 52, particularly impact-resistant. It goes without saying that access door 52 could alternatively be made of a different material, for example, a metal alloy.

[0075] Preferably, the access door 52 includes a peripheral sealing gasket to limit disturbances to the first airflow F1.

[0076] With reference to figures 4 to 6, the mechanical linking member 53 connects the access door 52 to the housing 4. In this example, as shown on the figure, the access door 52 has a first end 52A mechanically connected to the housing 4 by the mechanical linking member 53, and a free end 52B, so as to form a hinged access door 52.

[0077] According to one aspect of the invention, the mechanical linkage 53 is configured, on the one hand, to maintain the access door 52 in the closed position P0 by default (as shown in the figure) and, on the other hand, to open the access door 52 into the open position P1 following the application of a force G by the foreign body CO on the access door 52 (as shown in the figure). In other words, thanks to the mechanical linkage 53, the access door 52 is in the closed position P0 by default, to allow optimal circulation of the first airflow F1 in the interior zone Z1, when no foreign body CO enters the inlet of the interior zone Z1.

[0078] Preferably, the mechanical linkage 53 is a passive element, ensuring that the access door 52 is positioned by default in the closed position P0, unlike, for example, an element requiring an electrical power supply. In this example, the mechanical linkage 53 includes a spring. For example, the mechanical linkage 53 is in the form of a hinge in which a spring is mounted, in this example a helical spring. It goes without saying that the mechanical linkage 53 could alternatively be in a different form, for example a pneumatic cylinder whose compressibility of fluid would allow it to act as a spring.

[0079] Thus, in this example, the mechanical linkage 53, which includes a spring, is configured to operate between a rest state Q0 (shown in Figures 4 and 5), the default state in which the spring is not under load and the access door 52 is in the closed position P0, and a stressed state Q1 (shown in Figure 1), in which the access door 52 is in the open position P1. In this example, where the spring is a helical spring, it has a spring torque between 1000 and 3000 Nm. The spring torque is therefore greater than the aerodynamic forces applied by the first airflow F1 in the inner zone Z1 on the inner wall 41, which allows the access door 52 to remain in the closed position P0, despite the force applied by the incoming airflow. The spring torque is also, preferably, less than the force produced by the impact of a large foreign body CO, for example, a bird.In this example, the impact of a foreign body CO generates on the access door 52 a force of between 5000 N and 15000 N, as will be described in more detail later.

[0080] A mechanical linkage 53 is described, connected to the housing 4 at the first end 52A. However, it is understood that the mechanical linkage 53 could alternatively be connected to the free end 52B of the access door 52 to place it in the closed position P0 by a predetermined tensile force, for example. In this embodiment, the first end 52A of the access door 52 would be mechanically connected to the housing 4, for example, by a simple hinge.

[0081] In one embodiment, with reference to the, the interception system 5 includes a detection device 54 for occurrences of openings of the access door 52. Such a detection device 54 is mounted, in a first embodiment, on the free end 52B of the access door 52 or on the inner wall 41 at the level of the opening provided by the blind housing 51 (on the side opposite the mechanical linking member 53) and allows the detection of a contact or a lack of contact between the free end 52B of the access door 52 and the inner wall 41 of the intermediate housing 4. An occurrence of lack of contact makes it possible to determine the number of openings of the access door 52 for example. In a second embodiment, the detection device 54 is mounted at the level of the mechanical linkage 53 and allows, for example, the torque of the spring to be measured, which makes it possible to detect an opening of the access door 52.It goes without saying that the detection device 54 could alternatively take a different form. In this example, the detection device 54 is connected to a computer 9 in the aircraft and informs the pilot of the number of times the access door 52 is opened. This allows, for example, the detection of a high frequency of openings, indicating a significant quantity of foreign bodies intercepted.

[0082] In one embodiment, the interception system 5 includes a measuring device 55 for the mass of CO foreign bodies present in the blind housing 51. Preferably, the measuring device 55 is positioned on an interior surface of the blind housing 51. In this example, the measuring device 55 is in the form of a force sensor capable of measuring the pressure exerted by the weight of one or more CO foreign bodies on the interior surface of the blind housing 51, by gravity. The measuring device 55 is, in this example, connected to the aircraft's computer 9 and informs the pilot of the presence of CO foreign bodies captured by the interception system 5. This makes it possible to detect a significant mass of CO foreign bodies, indicating, for example, that it is necessary to empty the blind housing 51.

[0083] A method for capturing a foreign body CO in the turbomachine 1, using the interception system 5 described previously, with reference to figures 4 to 7, will now be described.

[0084] In a preliminary step E0, shown in Figure 1, the access door 52 is initially in the closed position P0. In this example, the mechanical linkage 53 includes a helical spring, initially in the rest state Q0, which holds the access door 52 in the closed position P0. Therefore, in this example, the mechanical linkage 53 has a sufficiently large spring torque to maintain the access door 52 in the closed position P0, even under the application of aerodynamic forces due to the first airflow F1 entering the narrowing portion 15 of the inner zone Z1. Indeed, as described previously, the first airflow F1 enters the inner zone Z1 along the turbomachine axis X from upstream to downstream. As such, at the inlet of the gooseneck-shaped narrowing portion 15, the first airflow F1 is forced against the inner wall 41 of the housing 4.

[0085] A foreign body CO then passes through the propulsion organ 2 and arrives at the entrance of the inner zone Z1.

[0086] In a first step E1, with reference to the, the foreign body CO, carried by the first air flow F1, strikes the access door 52 in a direction substantially parallel to the axis of the turbomachine X. Due to its inertia, the foreign body CO then exerts a force G on the access door 52, the force G being greater than the torque of the mechanical linkage 53.

[0087] In a second step E2, with reference to the, following the force G exerted by the foreign body CO, the access door 52 passes into the open position P1 and the foreign body CO is introduced into the blind housing 51. In particular, in this example, the foreign body CO is carried until it reaches the bottom of the blind housing 51, that is to say, until it reaches the storage portion 51B.

[0088] With reference to the [reference to the previous example], when the foreign body CO is located in the storage portion 51B of the blind housing 51, the latter ceases to exert the force G on the access door 52. No force then opposes the torque of the mechanical linkage 53, which is no longer constrained and returns to its rest state Q0. Furthermore, the foreign body CO present in the storage portion 51B does not hinder the closing of the access door 52, which is free to move within the travel portion 51A. The access door 52 is then automatically placed in the closed position P0, in a step E3, and re-establishes the continuity of the inner wall 41 of the inner casing 4, thus ensuring the aerodynamics of the inner zone Z1.

[0089] Advantageously, CO foreign bodies of insufficient size exert a force G lower than the torque of the mechanical linkage 53, which keeps the access door 52 closed and allows the small CO foreign bodies to be ingested without risk of damage. This makes it possible to intercept only the CO foreign bodies that pose a risk to the turbomachine 1.

[0090] In one embodiment, the method includes a fourth step of detecting several occurrences of opening the access door 52, by the detection device 54. A signal is then transmitted, via a computer 9, to the aircraft pilot who determines the number of occurrences of opening the access door 52. The latter can then report a significant number of CO foreign bodies captured, allowing, during a cleaning operation for example, the emptying of the blind housing 51 to remove all the CO foreign bodies in preparation for a future takeoff.

[0091] In one example, the process includes a fifth step of measuring, by the measuring device 55, the mass of CO foreign bodies present in the storage portion 51B of the blind housing 51. A signal is then transmitted, for example, via the computer 9, to the aircraft pilot who determines that one or more CO foreign bodies have been captured by the interception system 5. The pilot can then report a significant number of captured CO foreign bodies, making it possible to plan a cleaning operation, for example, to empty the blind housing 51 and remove all the CO foreign bodies.

[0092] A fourth step of detecting occurrences of openings of the access door 52 and a fifth step of measuring the mass of foreign bodies CO present in the blind housing 51 are described; however, it is understood that the detection and measurement steps can be carried out independently of each other in an alternative or complementary manner.

[0093] The interception system according to the invention advantageously limits the risk of the turbomachine ingesting, for example, an entire bird, thus limiting the risk of damage to the turbomachine. Thanks to the interception system according to the invention, it is possible to capture foreign bodies larger than debris without affecting the aerodynamics of the internal area, thereby ensuring optimal turbomachine performance.

[0094] Thanks to an interception system mounted directly downstream of the turbomachine's propulsion unit, the system eliminates any risk of a foreign body entering the compressor, thus preventing the risk of damage.

Claims

Gas turbomachine (1) for aircraft comprising a casing (4) delimiting an inner zone (Z1) for the circulation of a first airflow (F1) and an outer zone (Z2) for the circulation of a second airflow (F2), the casing (4) comprising a radially inner wall (41), externally delimiting the inner zone (Z1), and a radially outer wall (42), internally delimiting the outer zone (Z2), the gas turbomachine (1) comprising at least one compressor (11), one combustion chamber (12) and at least one turbine (13), the first airflow (F1) circulating from an upstream to a downstream along a turbomachine axis (X) in the inner zone (Z1) at least to supply the combustion chamber (12),The gas turbomachine (1) is characterized in that it comprises at least one interception system (5) for at least one foreign body (CO) mounted in the internal zone (Z1) upstream of the compressor (11) and comprising: a blind housing (51) formed in the inner wall (41) of the casing (4), the blind housing (51) comprising a storage portion (51B) intended to receive the foreign body (CO), an access door (52) to the blind housing (51), the access door (52) being configured to move between: a closed position (P0) in which it partially forms the inner wall (41) of the casing (4), and an open position (P1) in which the inner wall (41) of the casing (4) is discontinuous, allowing access to the blind housing (51), a mechanical linkage (53) connecting the access door (52) to the casing (4), configured, on the one hand, to maintain by default the access door (52) in the closed position (P0) and, on the other hand,to open the access door (52) into the open position (P1) following the application of a force (G) by the foreign body (CO) on the access door (52), the mechanical linkage (53) comprising a spring, the spring being a helical spring having a spring torque, the spring torque being between 1000 and 3000 Nm. gas turbomachine (1) according to claim 1, wherein the inner zone (Z1) is in the form of an inner vein comprising a narrowing portion (15), the interception system (5) is mounted in the narrowing portion (15). Gas turbomachine (1) according to any one of claims 1 to 2, the gas turbomachine (1) being free of a discharge valve upstream of the compressor (11), the discharge valve being configured to create a circulation channel of a discharge airflow from the inner zone (Z1) to the outer zone (Z2). Gas turbomachine (1) according to any one of claims 1 to 3, wherein the mechanical linking member (53) is a passive member. Gas turbomachine (1) according to any one of claims 1 to 4, wherein, in closed position (P0), the access door (52) forms a continuous aerodynamic surface with the inner wall (41) of the casing (4). Gas turbomachine (1) according to any one of claims 1 to 5, wherein the storage portion (51B) comprises a foreign body storage capacity greater than 1L, preferably greater than 3L. Gas turbomachine (1) according to any one of claims 1 to 6, wherein the storage portion (51B) has a storage height (H51B), defined radially with respect to the turbomachine axis (X), of between 80 and 220mm. gas turbomachine (1) according to claim 7, wherein the storage portion (51B) has a storage length (L51B), defined along the turbomachine axis (X), of between 1 and 1.5 times the storage height (H51B). Gas turbomachine (1) according to any one of claims 1 to 8, wherein the interception system (5) includes a detection device (54) for occurrences of opening of the access door (52). Gas turbomachine (1) according to any one of claims 1 to 9, wherein the interception system (5) includes a device for measuring the mass of foreign bodies (CO) present in the blind housing (51). Method of capturing a foreign body (CO) in a gas turbomachine (1) according to any one of claims 1 to 10, by means of the interception system (5), the mechanical linkage member (53) initially maintaining by default the access door (52) in the closed position (P0), the method comprises the steps of: applying (E1) a force (G), by the foreign body (CO), on the access door (52), and moving (E2) the access door (52) into the open position (P1), the foreign body (CO) being stored in the storage portion (51B) of the blind housing (51). Capture method according to claim 11, the capture method subsequently comprising a step consisting of automatically moving (E3) the access door (52) into the closed position (P0) following the cessation of the application of the force (G) by the foreign body (CO) on the access door (52).

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