DETECTION OF A SIDEWIND ON A TURBOME FROM ENGINE DATA

Description

Technical Field

[0001] The invention relates to the field of monitoring a turbomachine of an aircraft, and more particularly the detection of a crosswind, especially for assistance in aeronautical maintenance. Previous technique

[0002] Today, we are seeing the systematic implementation of predictive maintenance services. In this way, engine manufacturers are seeking to anticipate, as effectively as possible, failures that could affect aircraft engines. The implementation of these services has also accelerated since the introduction of flight-hour contracts to the civil aviation market.

[0003] These predictive maintenance services rely primarily on measurements acquired during one or more aircraft flight missions. These measurements are representative not only of an engine's behavior but also of the specific conditions encountered during the acquisition process. More specifically, logistical and material requirements for implementing these maintenance services are proposed based on an analysis of these measurements.

[0004] For example, representative measurements of engine behavior can relate to various variables, such as turbine shaft speed, pressure and / or temperature and / or oil level in an oil circuit, fuel flow rate, exhaust gas temperature, etc. Representative measurements of the acquisition context, on the other hand, can relate to other variables, such as weather, piloting, engine aging, aircraft weight, etc.

[0005] Conventionally, these measurements are acquired by onboard aircraft systems and made available to a ground-based receiving device owned by the aircraft manufacturer for analysis. This transfer occurs either during the flight mission, typically via satellite link, or after landing by downloading the data from a memory location where the measurements have been stored.

[0006] For example, document WO 2020 / 201652 describes a method for monitoring an engine based on at least two measurements, one of which is normalised with respect to the other, and the monitoring consisting of the detection of an anomaly on an abnormal drift of the normalised indicator.

[0007] A method for starting a turbomachine in the presence of a tailwind based on monitoring a turbomachine from a set of information is also known from document FR 2 097 897.

[0008] However, in the absence of data from avionics (aircraft systems such as a Pitot tube) and / or ground-based weather stations, there is no known method to determine whether an aircraft engine has experienced a crosswind based on satellite data, such as ACARS data, or on engine data, such as Continuous Engine Operational Data (CEOD) from the ground, let alone from flight. The absence of this data may be related to: Avionics system failures, for example related to a technical problem preventing the aircraft's onboard measurement, acquisition, processing, and recording systems from communicating with the ground systems of the aircraft manufacturer, the airline, and / or an original equipment manufacturer (OEM), such as an aircraft engine manufacturer, or, regardless of agreements with the airline or aircraft manufacturer, from transmitting data (data is not retrieved due to a technical failure of the onboard retrieval / transmission system: computer, transmission system, data storage device), a blockage of access to avionics data (prohibition of the OEM accessing this data - decision by the airline), linked, for example, to a data governance problem, or an unavailability of avionics data (the aircraft may have transmitted the data and it is stored,and available to the OEM, but the OEM is unable to retrieve them due to technical problems with the ground data retrieval system: for example, the OEM's information systems or those implemented on board the aircraft (airline system) are unable to communicate or are not performing adequately). This can be due to a blockage of access to ground data (ground pressure sensors, radars, and any ground-based systems within the airport perimeter, meteorological stations, state systems, etc.) or irrelevance (for determining the aircraft's current situation in flight).

[0009] However, knowledge of crosswind experience makes it possible to guide the regulation of an engine (especially at start-up), but also to improve damage models (asymmetric physical stresses on a blade, a shaft) of a turbomachine or to standardize other monitoring sensitive to this aerodynamic phenomenon.

[0010] For both taxiing and flight conditions, there is a need to detect the potential presence and direction of crosswinds acting on aircraft engines based on engine data, in the absence of data from ground stations or avionics. The technical background includes, in particular, document US6253126. Description of the invention

[0011] The invention aims to provide a solution for detecting crosswind conditions for aircraft turbomachinery in the absence of data from ground station or satellite data or avionics data.

[0012] An object of the invention proposes a method for detecting the presence of a crosswind for a turbomachine of an aircraft, the aircraft comprising at least two turbomachines arranged on either side of a main axis of the aircraft extending between a nose of the aircraft and a tail of the aircraft, said turbomachines each comprising a low-pressure shaft and an assembly of at least three sensors for regulating the operation of the turbomachine, a first sensor of the assembly being configured to measure the speed of the low-pressure shaft, a second sensor of the assembly being configured to measure a first pressure or temperature at a first location on the turbomachine, and a third sensor of the assembly being configured to measure a second pressure or temperature at a second location on the turbomachine.

[0013] According to a general feature of the invention, the process comprises the following steps: for each turbomachine, an acquisition (E0) of data from the set of at least three sensors, for each turbomachine, a normalization (E1) of said first pressure or temperature with respect to the low-pressure shaft regime and the second pressure or temperature, a comparison (E2) of the normalized first pressure or temperature of one turbomachine to the normalized first pressure or temperature of said at least one other turbomachine of the aircraft, a detection (E3+E4) of the presence of a crosswind from the result of the comparison.

[0014] The step of normalizing the first pressure or temperature makes it possible to compare the first pressures of each turbomachine in the aircraft.

[0015] For each turbomachine, the first pressure or temperature sensor configured to measure the initial pressure or temperature is located on the same side of the turbomachine, as turbomachines are generally mass-produced without distinction between right and left-hand orientations. Furthermore, the axis of the turbomachines around which the moving parts rotate is aligned in the same direction, corresponding to the aircraft's main axis. Consequently, the turbomachines on the same aircraft should experience the same aerodynamic disturbance related to their respective nacelle. Therefore, in theory, there should be no difference in the initial pressure or temperature readings measured on the turbomachines of the same aircraft.

[0016] However, there is an aerodynamic masking phenomenon also known as "Dutch Roll." The dynamics of Dutch Roll are well-known and demonstrate the inherent stability (by design) of an aircraft. The phenomenon is initiated and maintained by successive aerodynamic masking of a wing by the aircraft's fuselage as the aircraft enters a yaw.

[0017] More specifically, initially, the aircraft begins a right yaw. The right wing becomes masked by the aircraft's fuselage. The masked wing experiences a loss of relative wind speed, and its lift drops compared to the left wing, which undergoes the opposite phenomenon: a moment develops along the aircraft's axis, and a roll begins to the right. The left wing rises, its drag increases (its lift to a lesser extent), which introduces a moment along the rudder axis, causing the aircraft to begin a left yaw. The masking diminishes, the right wing regains its lift, and the aircraft begins a left roll. And so on.

[0018] Aerodynamic masking, or "Dutch Roll," generated by the aircraft's body and experienced by one or the other of the turbomachines introduces a difference in the initial pressure or temperature values ​​measured for the turbomachines of the same aircraft. This difference is determined during the comparison stage and provides an indication of the presence of a crosswind.

[0019] According to a first aspect of the tailwind detection method, the method may further include a determination of the azimuthal direction of the detected crosswind from the result of the comparison.

[0020] According to a second aspect of the tailwind detection method, the method may further include a determination of the detected crosswind speed.

[0021] According to a third aspect of the tailwind detection method, the detection step is performed using an averaged result from the comparison step. This averaged result is obtained by comparing a normalized first pressure or temperature average to a normalized first pressure or temperature average of at least one other turbomachine on the aircraft. The averages are calculated from measurements acquired during the same time window, or alternatively, from an average of comparisons based on the results of comparisons determined during a time window. The average of the measurements or the average of the comparisons can be calculated over an acquisition period of, for example, 30 seconds to obtain approximately 1200 measurements.The averaged comparison can be carried out on sliding time windows to avoid false alarms related to local and fleeting disturbances (gusts of wind, flow stall at the edge of the nacelle lips), especially if the first pressure measured is a total pressure.

[0022] According to the invention, with respect to the direction of the airflow in the turbomachine, the first pressure or temperature of a turbomachine is measured upstream of a low-pressure compressor of the turbomachine, and the second pressure or temperature is measured downstream of said low-pressure compressor, the low-pressure compressor being coupled to said low-pressure shaft.

[0023] In another object of the invention, an aircraft is proposed comprising at least two turbomachines arranged on either side of a main axis of the aircraft extending between a nose of the aircraft and a tail of the aircraft, said turbomachines each comprising a low-pressure shaft and an assembly of at least three sensors for regulating the operation of the turbomachine, a first sensor of the assembly being configured to measure the speed of the low-pressure shaft, a second sensor of the assembly being configured to measure a pressure or a temperature at a first location on the turbomachine, and a third sensor of the assembly being configured to measure a pressure or a temperature at a second location on the turbomachine.

[0024] According to a general feature of the aircraft according to the invention, the aircraft includes a crosswind detection system for an aircraft turbomachine, the system comprising: means for acquiring data from said sets of at least three sensors, normalization means configured to normalize said first pressure or temperature with respect to the low-pressure shaft regime and the second pressure or temperature, comparison means configured to compare the first normalized pressure or temperature of a turbomachine to the first normalized pressure or temperature of said at least one other turbomachine of the aircraft, and detection means configured to generate a crosswind presence signal from the signal delivered by the comparison means.

[0025] Temperature sensors can be selected from various types, such as thermocouple sensors or resistance temperature detectors (RTDs), and pressure sensors can be selected from various types, such as strain gauges, piezoelectric gauges, semiconductor pressure sensors, and others. Pressure sensors can measure static pressure and / or total pressure. Furthermore, both pressure sensors can be integrated into a data acquisition unit to which pressure samples are transmitted via pipelines from points of interest.

[0026] According to one aspect of the aircraft, the turbomachines can be symmetrical with respect to the main axis of the turbomachine.

[0027] According to a second aspect of the aircraft, said second sensor and said third sensor of the assembly measure the same thermodynamic quantity, either pressure or temperature.

[0028] According to a third aspect of the aircraft, the sensors regulating the operation of the turbomachine in each assembly are sensors of the aircraft's electronic turbomachine control system.

[0029] The process relies on the acquisition and processing of data from the control sensors of each engine of such an aircraft. Control sensors are those involved in thrust control and maintaining the proper functioning of the turbomachine: they are part, along with the engine control computer, of the electronic control system also known as "FADEC," which stands for "Full Authority Digital Engine Control."

[0030] According to the invention, the second sensor is mounted upstream of a turbomachine blower to which the second sensor is associated, and the third sensor is mounted downstream of the turbomachine blower to which the third sensor is associated, the blower being coupled to said low-pressure shaft. Brief description of the drawings

[0031] [ Fig. 1 ] There figure 1 schematically represents an aircraft. Fig. 2 ] There figure 2 schematically represents a cross-sectional view of a turbomachine from the aircraft. figure 1 . [ Fig. 3 ] There figure 3 presents a flowchart of a method for detecting the presence of a crosswind for a turbomachine of the aircraft. figure 1 . [ Fig. 4 ] There figure 4 schematically presents a system for detecting the presence of a crosswind for a turbomachine 5 of an aircraft of the figure 1 . Description of the implementation methods

[0032] On the figure 1 is shown a schematic view of an aircraft 1 comprising a nose 2, a tail 3, a main axis X extending between the nose 2 and the tail 3 of the aircraft 1, two wings 4 extending each from one side of the main axis X, and two turbomachines 5 arranged symmetrically with respect to the main axis X, each turbomachine 5 being mounted on a separate wing 4.

[0033] On the figure 2 , is schematically represented a cross-sectional view of an upper half of a turbomachine 5 of aircraft 1.

[0034] In the example shown on the figure 2Each turbomachine 5 of the aircraft 1 is a twin-spool, twin-flow turbomachine. The turbomachine 5 comprises, from upstream to downstream along a Y-axis (parallel to the main X-axis) of the turbomachine 1 in the direction of gas flow, an air inlet 50, a fan 51, a low-pressure (or LP) compressor 52, a high-pressure (or HP) compressor 53, a combustion chamber 54, a high-pressure turbine 55, and a low-pressure turbine 56.

[0035] The turbomachine 5 further comprises a primary flow 57 and a secondary flow 58 separated by an intermediate casing 59. The primary flow 57 extends downstream of the fan 51 and is radially bounded by the intermediate casing 59. The primary flow 57 includes the low-pressure compressor 52, the high-pressure compressor 53, the combustion chamber 54, and the high- and low-pressure turbines 55 and 56. The secondary flow 58 extends around the primary flow 57, also downstream of the fan 51. The secondary flow 58 extends radially between the intermediate casing 59 and an outer casing extending around the intermediate casing 59.

[0036] The turbomachine 5 further includes a set of three sensors for regulating the operation of the turbomachine 5, the set comprising a first sensor 6 configured to measure the speed of the low pressure shaft, a second sensor 7 configured to measure a first pressure at the height of the air inlet 50 of the turbomachine 5, i.e. upstream of the fan 51, and a third sensor 8 configured to measure a second pressure downstream of the fan 51 of the turbomachine 5.

[0037] Pressure sensors are strain gauges, piezoelectric gauges, or semiconductor pressure sensors.

[0038] The first, second and third sensors of each turbomachine 5 are sensors integrated into the electronic control system also known as “FADEC”.

[0039] On the figure 3is represented a logic diagram of a method for detecting the presence of a crosswind for a turbomachine 5 of an aircraft 1.

[0040] The process first includes a first step 300 of acquiring data from the three sensors 6, 7 and 8 for each of the two turbomachines 5 of the aircraft.

[0041] The process then includes a second normalization step 310 of the first pressure for each turbomachine 5. This normalization step 310 consists of normalizing for each turbomachine 5 the first pressure measured by the second sensor 7, i.e. the pressure upstream of the blower 51, with respect to the low pressure shaft speed measured by the first sensor 6 and the second pressure measured by the third sensor 8.

[0042] In a third step 320, the process performs a comparison of the first normalized pressure of one turbomachine 5 of aircraft 1 with the first normalized pressure of the other turbomachine 5 of aircraft 1. The comparison can be performed by subtracting the values ​​or by determining a ratio between the two values.

[0043] In a fourth step 330, the process includes a step for detecting the presence of a crosswind based on the result of the comparison. The detection step includes, in particular, comparing the result of the subtraction or division calculated in the previous step 320 to a detection threshold to determine whether or not a crosswind is present.

[0044] The detection step also allows, from the sign of the result of the subtraction or from the value of the calculated ratio, to determine the azimuthal direction of the detected crosswind.

[0045] The detection step can be performed using an averaged comparison result. This can be done by averaging the comparison results over a time window of approximately 30 seconds, for example. Alternatively, an averaged comparison can be performed by first averaging the data acquired by the sensors and then comparing the resulting averages after normalization.

[0046] On the figure 4A crosswind detection system 100 for an aircraft turbomachine 5 is schematically represented. The system 100 includes means 110 for acquiring data from the three sensors, normalization means 120 configured to normalize said first pressure with respect to the low-pressure shaft regime and the second pressure or temperature, comparison means 130 configured to compare the first normalized pressure of one turbomachine to the first normalized pressure of the other turbomachine 5, and detection means 140 configured to generate a crosswind presence signal from the signal delivered by the comparison means.

[0047] The invention thus makes it possible to detect crosswind conditions for turbomachinery of an aircraft in the absence of data from ground station or satellite data or avionics data.

Claims

1. A method for detecting the presence of a crosswind for a turbomachine of an aircraft, the aircraft including at least two turbomachines disposed on either side of a main axis of the aircraft extending between a nose of the aircraft and a tail of the aircraft, said turbomachines each including a low-pressure shaft, a low-pressure compressor coupled to said low-pressure shaft, and a set of at least three sensors for controlling the operation of the turbomachine, a first sensor of the set being configured to measure the rating of the low-pressure shaft, a second sensor of the set being configured to measure a first pressure or temperature upstream of the low-pressure compressor of the turbomachine with respect to the direction of the air flow in the turbomachine, and a third sensor of the set being configured to measure a second pressure or temperature downstream of said low-pressure compressor with respect to the direction of the air flow in the turbomachine, the method comprising the following steps: - for each turbomachine, acquiring (300) the data of the set of at least three sensors, - for each turbomachine, normalizing (310) said first pressure or temperature of a turbomachine with respect to the rating of the low-pressure shaft and with respect to the second pressure or temperature, - comparing (320) the normalized first pressure or temperature of a turbomachine with the normalized first pressure or temperature of said at least one other turbomachine of the aircraft, - detecting (330) the presence of a crosswind based on the result of the comparison.

2. The method for detecting the presence of a crosswind as claimed in claim 1, further comprising the determining of the azimuthal direction of the detected crosswind based on the result of the comparison.

3. The method for detecting the presence of a crosswind as claimed in one of claims 1 or 2, further comprising the determining of the speed of the detected crosswind.

4. The method for detecting the presence of a crosswind as claimed in one of claims 1 to 3, wherein the detecting step (330) is done based on an averaged result of the comparing step, the averaged result being obtained based on a comparison of an average normalized first pressure or temperature with an averaged normalized first pressure or temperature of said at least one other turbomachine of the aircraft, the averages being taken based on the measurements acquired during one and the same time window, or else based on an average of the comparisons made based on the results of the comparisons determined during a time window.

5. An aircraft (1) comprising at least two turbomachines (5) disposed on either side of a main axis (X) of the aircraft (1) extending between a nose (2) of the aircraft (1) and a tail (3) of the aircraft (1), said turbomachines (5) each including a low-pressure shaft, a fan (51) coupled to the low-pressure shaft, and a set of at least three sensors (6, 7, 8) for controlling the operation of the turbomachine (5), a first sensor (6) of the set being configured to measure the rating of the low-pressure shaft, a second sensor (7) of the set mounted upstream of the fan (51) of the turbomachine (5) with which the second sensor (7) is associated, the second sensor (7) being configured to measure a pressure or a temperature, and a third sensor (8) of the set mounted downstream of the fan (51) of the turbomachine with which the third sensor (8) is associated, the third sensor (8) being configured to measure a pressure or a temperature, characterized in that it comprises a system (100) for detecting a crosswind for an aircraft (1) turbomachine (5), the system (100) including: - means (110) for acquiring data from said sets of at least three sensors (6, 7, 8), - normalizing means (120) configured to normalize said first pressure or temperature par rapport with respect to the rating of the low-pressure shaft and with respect to the second pressure or temperature, - comparing means (130) configured to compare the normalized first pressure or temperature of a turbomachine (5) with the normalized first pressure or temperature of said at least one other turbomachine (5) of the aircraft (1), and - detecting means (140) configured to generate a signal of the presence of a crosswind based on the signal delivered by the comparing means (130).

6. The aircraft (1) as claimed in claim 5, wherein the turbomachines are symmetrical with respect to the main axis (X) of the aircraft.

7. The aircraft (1) as claimed in one of claims 5 or 6, wherein said second sensor (7) and said third sensor (8) of the set measure one and the same thermodynamic quantity from among the pressure or the temperature.

8. The aircraft (1) as claimed in one of claims 5 to 7, wherein the sensors (6, 7, 8) for controlling the operation of the turbomachine (5) of each set are sensors of the electronic control system of the turbomachines (5) of the aircraft (1).