Assembly made up of at least one aircraft turbine engine and an inertial measurement unit, and associated method

Abstract

The invention relates to an assembly comprising at least one turbine engine (2) for an aircraft, comprising a casing in which at least one rotary body is mounted to allow propulsion of the aircraft, with an air flow flowing from upstream to downstream in the turbine engine (2), at least one inertial measurement unit (3) mounted in the turbine engine (2), the inertial measurement unit (3) being configured to measure at least one turbine engine load applied to the turbine engine during a flight of the aircraft, and at least one computer configured to determine at least one malfunction of the turbine engine (2) on the basis of the turbine engine load.

Description

Assembly of at least one aircraft turbomachine and an inertial unit and associated method

[0001] The present invention relates to the field of monitoring the health status of an aircraft turbomachine, in particular, to enable its predictive maintenance.

[0002] When an aircraft performs maneuvers, for example, an upward climb or a sideways turn, or when it experiences a gust, an aircraft is subjected to significant accelerations and angular velocities. It is known to equip the aircraft with an inertial unit positioned in a central fuselage of the aircraft in order to measure the accelerations and angular velocities that apply to the aircraft.

[0003] When accelerations and angular velocities exceed a predetermined threshold, a maintenance operation is scheduled on aircraft turbomachines in order to verify that the accelerations and angular velocities have not impacted the proper functioning of said aircraft turbomachines.

[0004] In practice, there is no strong correlation between accelerations and angular velocities applied to the aircraft and aircraft turbomachinery malfunctions. As a result, maintenance scheduling is not optimal, increasing costs and downtime of turbomachinery.

[0005] The prior art discloses, from patent application FR3086699A1, a method for determining the quantity of oil in an oil tank of an aircraft turbomachine based on acceleration. EP2502047B1 teaches a method for measuring the fatigue of aircraft parts using several stress sensors and an inertial unit. US20170092021A1 teaches a monitoring system for vehicle maintenance.

[0006] The invention aims to eliminate at least some of these drawbacks. PRESENTATION OF THE INVENTION

[0007] The invention relates to an assembly comprising: at least one turbomachine for an aircraft comprising a casing in which at least one rotating body is mounted to enable propulsion of the aircraft, an air flow circulating from upstream to downstream in the turbomachine, at least one inertial unit mounted in the turbomachine, the inertial unit being configured to measure at least one turbomachine load during a flight of the aircraft, the turbomachine load comprising at least one acceleration applied to the turbomachine, and at least one computer configured to determine at least one malfunction of the turbomachine from the turbomachine load.

[0008] Thanks to the invention, the accelerations applied to the turbomachine are directly measured in the turbomachine. This makes it possible to determine in a relevant manner the amplitude as well as the acceleration cycles undergone by the turbomachine. The real impact on a turbomachine can thus be determined to carry out predictive maintenance or issue an alarm to warn the pilots.

[0009] Preferably, the turbomachine load comprises accelerations applied to the turbomachine along at least three axes. This determines an acceleration vector to accurately qualify the impact of a gust or maneuver.

[0010] Preferably the turbomachine load comprises at least one angular velocity applied to the turbomachine, preferably angular velocities applied to the turbomachine for at least three axes.

[0011] According to one aspect, the computer is configured to determine at least one operating point of the turbomachine from turbomachine load measurements and to compare the operating point to a predetermined model in order to determine a malfunction.

[0012] According to one aspect, the computer is embedded in the aircraft and configured to emit an alarm when a malfunction is determined. This makes it possible to assist a pilot of the aircraft reactively in the event of a malfunction. Preferably, the computer is embedded in the turbomachine in the aircraft.

[0013] According to one aspect, the turbomachine having a center of gravity, the turbomachine being suspended from the aircraft in a cantilevered manner, the inertial unit is mounted on a cantilevered part. This advantageously makes it possible to measure the deflections linked to the cantilever following a gust or other. The cantilevered part amplifies the oscillations and is optimally monitored.

[0014] According to one aspect, the turbomachine having a center of gravity, the turbomachine comprising at least a first suspension positioned upstream of the center of gravity and at least a second suspension positioned downstream of the center of gravity, the inertial unit is mounted between the first suspension and the second suspension, preferably, close to the center of gravity. This makes it possible to monitor the balance forces experienced by the turbomachine.

[0015] According to one aspect, the turbomachine comprising a primary stream feeding a combustion chamber, a secondary stream in which the air flow is accelerated and a separation casing separating the primary stream from the secondary stream, the inertial unit is mounted in the separation casing. This makes it possible not to increase the size of the turbomachine and to remain as close as possible to the axis of the turbomachine to obtain relevant accelerations.

[0016] According to one aspect, the inertial unit comprises a plurality of elementary modules which are connected to each other. Preferably, the elementary modules are at the same axial position defined along the X axis and at different azimuthal positions. This advantageously makes it possible to distribute the constraints of size, assembly and accessibility. According to a preferred aspect, the acceleration sensors and the gyroscopes belong to different elementary modules of the inertial unit in order to optimize compactness and operation.

[0017] The invention also relates to an aircraft comprising at least one lateral wing and at least one assembly as presented previously, the turbomachine of the assembly being suspended from the lateral wing. This makes it possible to measure the impact of positioning the turbomachine under a lateral wing as well as the impact of the flexibility of said lateral wing.

[0018] The invention also applies to an aircraft comprising a fuselage and a turbomachine mounted on a rear part of the fuselage. This makes it possible to measure the load applied to the turbomachine independently of the load applied to the aircraft.

[0019] The invention also relates to a method for determining at least one malfunction of a turbomachine in an assembly as presented previously, the method comprising steps consisting of:Measuring turbomachine loads applied to the turbomachine during a flight of the aircraft, andDetermining at least one malfunction of the turbomachine from the turbomachine loads. PRESENTATION OF FIGURES

[0020] 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.

[0021] This is a schematic representation of an aircraft when subjected to a gust.

[0022] This is a schematic representation of the accelerations applied to the turbomachine and the accelerations applied to the aircraft following a gust.

[0023] This is a schematic representation of a first embodiment of a turbomachine equipped with an inertial unit.

[0024] This is another schematic representation of the turbomachine of the.

[0025] This is a schematic representation of a second embodiment of a turbomachine equipped with an inertial unit.

[0026] This is another schematic representation of the turbomachine of the.

[0027] This is a schematic representation of a method for determining a malfunction.

[0028] This is a schematic representation of an abacus for determining a malfunction.

[0029] It should be noted that the figures set out the invention in detail to implement the invention, said figures can of course be used to better define the invention where appropriate. DETAILED DESCRIPTION OF THE INVENTION

[0030] The invention will be presented for an aircraft comprising one or more turbomachines to provide its propulsion. With reference to the, the aircraft 1 comprises a central section 10 and two lateral wings 11. A turbomachine 2 is mounted on each lateral wing 11. It goes without saying that the number and position of the turbomachines 2 could be different.

[0031] Still with reference to the, the aircraft 1 comprises an inertial module 12 positioned in the central section 10 and which makes it possible to measure aircraft loads F1, applied to the aircraft 1 during its movement. An aircraft load F1 notably comprises accelerations along three axes and angular velocities along three axes. Such an inertial module 12 is not mandatory and is presented to highlight the advantages of the present invention.

[0032] According to the invention, with reference to the, each turbomachine 2 further comprises an inertial unit 3 configured to measure turbomachine loads F2 experienced by the turbomachine 2 during the movement of the aircraft 1. In other words, in the present configuration, there is a measurement of the aircraft loads F1 and a measurement of the turbomachine loads F2. In this example, only the vertical acceleration is shown schematically for the sake of clarity.

[0033] Preferably, the inertial unit 3 is configured to measure several accelerations applied to the turbomachine 2 during a flight of the aircraft 1 along several axes, preferably three. Preferably, the inertial unit 3 is configured to measure at least one angular speed applied to the turbomachine 2 during a flight of the aircraft 1. Preferably, the inertial unit 3 is configured to measure several angular speeds applied to the turbomachine 2 during a flight of the aircraft along several axes.

[0034] The various measurements of the inertial unit 3 can be integrated in order to determine angular orientations, speeds or other factors. All the measurements of the inertial unit 3 belonging to the turbomachine 2 are hereinafter referred to as “turbomachine load F2” for the sake of clarity and conciseness.

[0035] With reference to the, there is shown a gust movement RAF undergone by the aircraft 1 and by each turbomachine 2 mounted under a side wing 11. The turbomachine load F2 is different from the aircraft load F1 for several reasons.

[0036] According to a first aspect, the transport of forces linked to accelerations and moments linked to angular speeds between a point of the aircraft 1 and a point of the turbomachine 2 will modify the turbomachine load F2 in relation to the aircraft load F1. This is particularly notable during a maneuver or a gust.

[0037] According to a second aspect, the turbomachine load F2 depends on the dynamic response of the wing to a mechanical stress. Considering the turbomachine 1 as a mass and the wing as a spring, if the mass undergoes accelerations / moments, the wing will respond and amplify these accelerations / moments. For example, a purely vertical gust may not cause rotation of the fuselage of the aircraft 1 but may cause a dynamic response of the wing.

[0038] The two effects below can, in certain cases, be cumulative depending on the type of event experienced.

[0039] In the present case, as illustrated in, the turbomachine loads F2 are higher than the aircraft loads F1.

[0040] With particular reference to illustrating a simplified implementation example, it is noted in particular that the aircraft loads F1 are in the form of an acceleration step PAL while the turbomachine loads F2 are in the form of strong oscillations at the start of the step (first period T1) and at the end of the step (second period T2). During the first period T1, that is to say during the acceleration of the aircraft 1, the turbomachine 2 is subjected to turbomachine loads F2 which are amplified by its positioning on a lateral wing 11 and by the flexibility of said lateral wing 11. The amplitude of the turbomachine load F2 can thus be amplified up to double compared to the aircraft load F1 received at the input. An excessive amplitude can lead to an increase in the clearances of the turbomachine 2 and degrade its performance.

[0041] The oscillations correspond to several acceleration cycles of the turbomachine 2, which is different from aircraft 1 which only undergoes a single PAL acceleration stage. The repetition of acceleration cycles is likely to lead to early malfunctions and are not perceived by aircraft 1. The repetition of cycles can in particular affect the fatigue resistance of the turbomachine 2.

[0042] The measurements of the F2 turbomachine loads are thus important data for an aircraft pilot given that an acceleration threshold or a number of cycles can be exceeded by the turbomachine 2 without being exceeded by the aircraft 1.

[0043] Several embodiments of the integration of an inertial unit 3 in a turbomachine 2 will now be presented with reference to figures 3 to 6.

[0044] In this example, each turbomachine 2 has a double-spool architecture with, on the one hand, a low-pressure spool and, on the other hand, a high-pressure spool. It nevertheless goes without saying that the invention applies to any type of architecture. The turbomachine 2 extends along an axis X which is oriented from upstream to downstream and makes it possible to accelerate an air flow from upstream to downstream.

[0045] As illustrated in Figures 3 to 6, each turbomachine 2 comprises from upstream to downstream: a propulsion member 20 (propeller or fan), a low-pressure compressor 21, a high-pressure compressor 22, a combustion chamber 23, a high-pressure turbine 24 and a low-pressure turbine 25. In this example, the propulsion member 20, the low-pressure compressor 21 and the low-pressure turbine 25 are connected by a low-pressure shaft 26. The high-pressure compressor 22 and the high-pressure turbine 24 are connected by a high-pressure shaft 27. The structure of such a turbomachine 2 is known and will not be presented in more detail.

[0046] With reference to figures 4 and 6, each turbomachine 2 comprises a primary vein V1 supplying the combustion chamber 23 and a secondary vein V2 in which the air flow accelerated by the propulsion member 20 moves.

[0047] Preferably, an inertial unit 3 comprises several acceleration sensors (accelerometers), in particular at least three in order to measure a horizontal acceleration, a vertical acceleration and an azimuthal acceleration. It goes without saying that the inertial unit 3 could comprise more than three acceleration sensors to measure different accelerations or to meet a need for redundancy.

[0048] Preferably, the inertial unit 3 comprises several gyroscopes, in particular at least three in order to measure different angular speeds (horizontal, vertical and azimuthal). It goes without saying that the inertial unit 3 could comprise more than three gyroscopes to measure different angular speeds or to meet a need for redundancy.

[0049] According to a first embodiment shown in figures 3 and 4, the turbomachine 2 is connected to the aircraft 1, in particular to a lateral wing 11, via suspensions S1, S2 which are mounted upstream of the turbomachine 2.

[0050] In this example, with reference to the, the turbomachine 2 has a center of gravity G and the suspensions S1, S2 are connected to the turbomachine 2 upstream of the center of gravity G. The turbomachine 2 is thus suspended in a cantilever.

[0051] For such a suspension mode, the inertial unit 3 is preferably positioned near the downstream part of the turbomachine 2 which is cantilevered as illustrated in. In this example, the suspensions S1, S2 are connected to a casing near the low pressure compressor 21 and the inertial unit 3 is positioned near a casing of the high pressure turbine 24.

[0052] With reference to the, the inertial unit 3 is preferably positioned in a separation casing 20 separating the two air streams V1, V2, near the high pressure turbine 24.

[0053] In order to withstand thermal stresses near the turbine, the inertial unit 3 preferably comprises thermal protection, for example a coating and / or a cooling device, in particular by blowing air.

[0054] According to a second embodiment shown in figures 5 and 6, the turbomachine 2 is connected to the aircraft 1, in particular to a lateral wing 11, via suspensions S1, S2 which are mounted respectively upstream and downstream of the turbomachine 2.

[0055] In this example, with reference to the, the turbomachine 2 has a center of gravity G, a first suspension S1 is connected to the turbomachine 2 upstream of the center of gravity G while a second suspension S2 is connected to the turbomachine 2 downstream of the center of gravity G. The turbomachine 2 is thus suspended in a balanced manner.

[0056] For such a suspension mode, the inertial unit 3 is preferably positioned close to the center of gravity G of the turbomachine 2. In this example, the first suspension S1 is connected to a casing close to the low pressure compressor 21, the second suspension S2 is connected to a casing close to the low pressure turbine 25 and the inertial unit 3 is positioned close to the center of gravity G, in particular, close to the high pressure compressor 22.

[0057] With reference to the, the inertial unit 3 is preferably positioned in the separation casing 20 separating the two air streams V1, V2, close to the center of gravity G, in particular, close to the high pressure compressor 22.

[0058] According to one aspect (not shown), if the space constraints are too great and do not allow the mounting of an inertial unit 3 with all its acceleration sensors and its gyroscopes (centralized structure), the inertial unit 3 can have a modular structure and comprise a plurality of elementary modules, the size of which is reduced, which are connected to each other. Preferably, the elementary modules are at the same axial position defined along the X axis and at different azimuthal positions. This advantageously makes it possible to distribute the space, mounting and accessibility constraints. According to one aspect, the acceleration sensors and the gyroscopes belong to different elementary modules of the inertial unit 3 in order to optimize compactness and operation.

[0059] In practice, the first embodiment is preferred. However, when space constraints or thermal constraints require it, the inertial unit 3 is positioned close to the center of gravity G as shown in the second embodiment.

[0060] According to one aspect of the invention, with reference to the, the aircraft 1 comprises an on-board computer 4, positioned in the fuselage or in a turbomachine 2, configured to acquire the turbomachine loads F2 from the inertial units 3 in order to transmit them during the flight or at its end to a ground computer 4' in order to allow remote processing and determine a DYS malfunction, for example, a risk of damage, a defect or a maintenance request. The ground computer 4' provides a flight report including the accelerations and the angular orientations (incidences) during the flight. The various data are preferably stored in a database so as to construct a mathematical learning model in order to allow predictive maintenance.

[0061] Alternatively, the onboard computer 4 can perform onboard processing of the turbomachine loads F2 to determine a DYS malfunction. Preferably, in the event of a DYS malfunction, the onboard computer 4 is configured to emit an alarm, in particular, in a cockpit of the aircraft. The alarm may be visual, audible, computer-based or other. Preferably, the alarm qualifies the type of DYS malfunction to provide precise information to the pilots of the aircraft 1 (no maintenance, upcoming maintenance, immediate maintenance, etc.). This makes it possible to react reactively in the event of a particular event (significant gust, etc.).

[0062] An example of processing turbomachine loads F2 will now be presented. As an example, an operating point Px is determined for the turbomachine 2 which depends, on the one hand, on the vertical acceleration Nz and, on the other hand, on a pitch angular velocity Wy. The vertical acceleration Nz and the pitch angular velocity Wy are determined by the inertial unit 3 of each turbomachine 2.

[0063] With reference to the, the operating point Px is compared to at least one predetermined model, here a predetermined abacus ABQ, which determines for example a first nominal zone Z1, a second low risk zone Z2 and a third high risk zone Z3. In this example, the higher the vertical acceleration Nz (expressed in G) and the higher the pitch angular velocity Wy (expressed in rad.s-1), the greater the risk as illustrated in the.

[0064] Thanks to the invention, any DYS malfunction specific to a turbomachine 2 is determined reactively and precisely. This makes it possible to implement relevant maintenance of a turbomachine 2 and reduce costs.

Claims

An assembly comprising at least one turbomachine (2) for an aircraft (1) comprising a casing in which is mounted at least one rotating body to enable propulsion of the aircraft (1), an airflow circulating from upstream to downstream in the turbomachine (2), at least one inertial unit (3) mounted in the turbomachine (2), the inertial unit (3) being configured to measure at least one turbomachine load (F2) during a flight of the aircraft (1), the turbomachine load (F2) comprising at least one acceleration applied to the turbomachine (2), and at least one computer (4, 4') configured to determine at least one operating point (Px) of the turbomachine (2) from measurements of the turbomachine load (F2) and to compare the operating point (Px) with a predetermined model (ABQ) in order to determine a malfunction (DYS) of the turbomachine (2). Assembly according to claim 1 in which the turbomachine load (F2) comprises accelerations applied to the turbomachine (F2) along at least three axes. Assembly according to one of claims 1 to 2, in which the turbomachine load (F2) comprises at least one angular speed applied to the turbomachine (F2), preferably, angular speeds applied to the turbomachine (F2) for at least three axes. Assembly according to one of claims 1 to 3, in which the computer (4) is on board the aircraft (1) and configured to emit an alarm when a malfunction (DYS) is determined. Assembly according to one of claims 1 to 4 in which, the turbomachine (2) having a center of gravity (G), the turbomachine (2) being suspended from the aircraft (1) in a cantilevered manner, the inertial unit (3) is mounted on a cantilevered part. Assembly according to one of claims 1 to 4 wherein, the turbomachine (2) having a center of gravity (G), the turbomachine (2) comprising at least a first suspension (S1) positioned upstream of the center of gravity (G) and at least a second suspension (S2) positioned downstream of the center of gravity (G), the inertial unit (3) is mounted between the first suspension (S1) and the second suspension (S2), preferably, close to the center of gravity (G). Assembly according to one of claims 1 to 6 in which, the turbomachine (2) comprising a primary vein (V1) supplying a combustion chamber (23), a secondary vein (V2) in which the air flow is accelerated and a separation casing (20) separating the primary vein (V1) from the secondary vein (V2), the inertial unit (3) is mounted in the separation casing (20). Aircraft (1) comprising at least one lateral wing (11) and at least one assembly according to one of claims 1 to 7, the turbomachine (2) of the assembly being suspended from the lateral wing (11). Method for determining at least one malfunction (DYS) of a turbomachine (2) in an assembly according to one of claims 1 to 7, the method comprising steps consisting of:Measuring turbomachine loads (F2) applied to the turbomachine (2) during a flight of the aircraft (1), andDetermining at least one malfunction (DYS) of the turbomachine (2) from the turbomachine loads (F2).

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