BE1026251B1 - Measurement method for testing a part of an aircraft turbomachine - Google Patents

Abstract

The invention relates to a measurement method for testing a part of an aircraft turbomachine on the basis of analog sensor output signals (11, 13, 13), comprising a step of synchronization by an analog device of at least some of these signals (61, 71; 62, 72; 63, 73) preceding a step of processing by an electronic device the synchronized signals.

Description

Measurement method for testing a part of an aircraft turbomachine

Technical area

The invention relates to a measurement method for testing a part of an aircraft turbomachine.

Prior art

When a part of an aircraft turbomachine is produced and / or developed, test measurements are normally carried out.

In certain cases, these tests are carried out by means of sensors able to measure the same physical quantity and include a step of acquisition and processing of output signals from these sensors.

Putting this last step into practice is likely to be long and tedious given the large number of data to be processed.

Summary of the invention

An object of the invention is to provide a measurement method for testing a part of an aircraft turbomachine which is faster to execute.

To this end, the invention proposes a measurement method for a test of a part of an aircraft turbomachine comprising the following steps:

(i) provide:

- the room ;

- sensors for measuring the same physical quantity, and able to supply analog signals corresponding to said physical quantity;

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- an analog electronic preprocessing device coupled to the sensors for preprocessing analog signals from the sensors; and

- an electronic processing device coupled to the electronic preprocessing device to deduce at least one item of information related to the physical quantity;

(ii) position the sensors at separate locations to measure the same physical quantity influenced at least partially by the part at these different locations;

(iii) analogically synchronize, and using the analog electronic preprocessing device, analog signals from the sensors;

(iv) process, using the electronic processing device, the signals synchronized in the previous step to deduce at least one item of information related to the physical quantity and one piece of item test information.

The method according to the invention makes it possible to carry out a measurement for a test of a part of an aircraft turbomachine which is particularly quick to execute.

In fact, since the sensors are positioned in separate locations in step (ii), the output signals from the sensors are generally phase-shifted over time. Step (iii) of signal synchronization allows these signals to be replaced in the same repository before their processing in step (iv). Consequently, this processing of the signals is facilitated, which allows a significant saving of time in the execution of the measurement for the test. Indeed, processing of non-synchronized signals is difficult in view of the prohibitive size of the files which are generated due to the amount of data to be acquired and to be processed during such a measurement for a test. In particular, the posterior synchronization of the signals from the pressure sensors is complex to implement by

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- 3 the engineer responsible for such processing. The method according to the invention is therefore faster and simpler to implement.

The method according to the invention also makes it possible to start and at least partially carry out processing of the signals in step (iv) without waiting for the end of the measurement for the test, and therefore without waiting for the end of their acquisition. In particular, and preferably, the step of processing part of the signals is carried out in parallel with a step of acquiring another part of the signals comprising the signals synchronized in step (iii).

Preferably, step (iv) of the method is executed by means of a very specialized acquisition and processing system comprising the electronic processing device. Advantageously, a high quality of the signals is thus obtained. The fact that such signals generate a greater number of data to be managed is not a problem during the execution of the method according to the invention since step (iii) of synchronization saves time in processing. of these signals. Thus, the method according to the invention makes it possible to carry out a measurement for a test whose implementation is also more effective.

Advantageously, an analog electronic device and an electronic processing device are well known to a person skilled in the art and their use allows faster and more efficient execution of the method according to the invention.

According to a preferred embodiment of the method, step (iii) comprises a step of adding a delay to each of the signals to be synchronized, the delay consisting of a positive, negative or zero time delay.

Preferably, a reference signal is chosen in step (iii) and these signals are aligned with this reference signal by means of the addition of a delay. When the reference signal is one of the signals, the delay in aligning the reference signal on itself is obviously zero. Advantageously, all the signals are thus synchronized, that is to say

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- 4 considered in the same time frame without phase difference between them, which greatly simplifies their treatment in step (iv).

Preferably, the reference signal is the last signal generated. This may or may not be included in the signals to be synchronized.

Preferably, the alignment delay is determined from a point and / or an area common to the reference signal and to each of the signals to be synchronized. The delay for aligning the reference signal with one of the signals is the time required to align the point and / or the common area of the reference signal with the point and / or the associated common area of one of the signals.

Otherwise formulated, according to a preferred embodiment of the method, step (iii) comprises a step of adding a delay to each of the signals to be synchronized, the delay consisting of a positive, negative or zero time delay; as well as the following substeps:

- choose a reference signal from the signals;

- identify a common area for each of the signals to be synchronized;

- determine the delay to add to each of these signals, the delay being a delay separating the common areas of the reference signal and each of these signals.

More preferably, step (iii) also includes the following sub-steps:

- decompose each of the signals to be synchronized into a collection of periods;

- identify common periods for each of these signals;

- determine a variation for each of the common periods of each of these signals, the variation consisting

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- 5 in a positive, negative or zero variation of time, of the delay added to each of the signals;

- add the variation to each of the common periods of each of these signals.

Advantageously, this more preferred embodiment of the method makes it possible to tarnish the account of periodic fluctuation of the output signals. Indeed, when an alignment delay of one of the signals on a reference signal is made from an identification of a common area, it may be that other portions of these two signals are not perfectly align due to local variations and / or disturbances of these two signals. Advantageously, this more preferred embodiment of the method recommends a periodic evaluation of these local variations and / or disturbances of these two signals.

According to one embodiment of the method, the part comprises at least one blade and / or at least one shell of the turbomachine. The method then consists of a measurement method for a test of at least one blade and / or at least one shell of an aircraft turbomachine.

In the case of this embodiment, the more preferred embodiment of the method is all the more advantageous when a period of one of the signals is capable of being defined as a signal section during the passage of a blade of the turbomachine when it is in motion. In this case, the variations in the alignment delay of one of the signals on a reference signal are particularly small between two consecutive blades, and the delay calculated for one blade can therefore be taken as a reference for the calculation of the next by means of a optional use of the delay variation to update this reference.

According to a preferred embodiment of the method when it comprises a step (iii) comprising a step of identifying a common area for each of the signals to be synchronized, this common area consists of an apex and / or a trough and / or a rising edge and / or a

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- 6 falling edge of a curve representing each of the signals to be synchronized.

According to a preferred embodiment of the method, step (iii) consists in synchronizing the signals.

Preferably, the signals synchronized in step (iii) consist of all the analog output signals.

According to a preferred embodiment of the method, it comprises a step of recording the signals processed in step (iv).

This step is preferably carried out using very sophisticated data acquisition, storage and recording techniques. Advantageously, a high quality of the signals is thus obtained. The phenomena sought during these measurements for tests having very short characteristic times, these are thus advantageously better detected by means of these high quality signals.

According to a preferred embodiment of the method, it comprises a step of detecting at least one defect in the part on the basis of the signals processed in step (iv).

According to a preferred embodiment of the method, step (iii) is preceded by a step of setting the turbomachine in motion.

According to a preferred embodiment of the method, step (i) comprises a step of supplying pressure sensors. Preferably, the sensors are pressure sensors.

Advantageously, the pressure sensors are well known to a person skilled in the art and their use allows the detection of a class of phenomena corresponding to faults in the blades and / or in the shrouds of the turbomachine when the latter is in motion. The sensors are preferably pressure sensors. Advantageously, a simple and effective execution of the method according to the invention is then obtained.

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- 7 According to a preferred embodiment of the method, step (i) comprises a step of supplying at least one device comprising at least three sensors positioned and oriented distinctly, and step (ii) comprises a positioning step of the at least one device near the part.

The supply and placement of such at least one device makes it possible to ensure that the sensors are advantageously placed and oriented adequately with respect to each other. This also advantageously makes it possible to reduce the time necessary for carrying out step (ii). The implementation of the method according to the invention is thus both accelerated and simplified.

As developed in the detailed description, in the case where the part comprises at least one blade and / or at least one turbomachine shell, the use of a pressure sensor or of such a device provided with at least three sensors is particularly advantageous because it makes it possible to carry out a particular embodiment of the invention consisting of a method of measuring an angle of an air flow for a test at the level of at least one blade and / or one shell of an aircraft turbomachine.

Brief description of the figures

Other characteristics and advantages of the present invention will appear on reading the detailed description which follows for the understanding of which reference will be made to the appended figures among which:

- Figure 1 illustrates a device comprising sensors which are able to be used during an execution of the method according to an embodiment of the invention;

- Figure 2 illustrates a schematic planar sectional view of a turbomachine during an execution of the method according to an embodiment of the invention;

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FIG. 3 illustrates curves representing a part of the analog output signals from the sensors during an execution of the method according to an embodiment of the invention.

The drawings of the figures are not to scale. Generally, similar elements are denoted by similar references in the figures. In the context of this document, identical or analogous elements may have the same references. In addition, the presence of reference numbers in the drawings cannot be considered to be limiting, including when these numbers are indicated in the claims.

Detailed description of particular embodiments of the invention

The present invention is described with particular embodiments and references to figures, but the invention is not limited by these. The drawings or figures described are only schematic and are not limiting.

FIG. 1 illustrates a device 4 comprising three sensors 11, 12, 13, preferably pressure sensors, which are able to be used during an execution of the method according to an embodiment of the invention. The sensors 11, 12, 13 are positioned and oriented in three distinct directions, these first two and the latter two respectively considered making a clockwise oriented angle between 60 to 75 degrees. Thus, a large number of good quality analog signals are generated, synchronized, acquired and processed thanks to an execution of the method according to the invention.

In addition, better detection of faults in a part of a turbomachine is obtained thanks to the large amount of information acquired and processed by means of these sensors 11, 12, 13.

Advantageously, it is easier to place such a device near the part to be tested than to place the three sensors, making sure

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- 9 of their respective positions with respect to each other. The implementation of step (ii) of the method according to the invention is thereby simplified and accelerated.

FIG. 2 illustrates a positioning of the device 4 after an execution of step (ii) of the method according to the invention. The positioning is shown in a schematic planar sectional view of a section 5 of a turbomachine comprising vanes 6, 7 and ferrules. After this execution of step (ii), the turbomachine is preferably set in rotational movement around the axis Z for the execution of step (iii). The device 4 comprising the sensors 11, 12 and 13 remains fixed during the rotational movement of the turbomachine. The positioning of the device 4 allows it to be in the path of the flows generated by the turbomachine, which advantageously makes it possible to process signals encoding air flow measurement information for a test of the blades 6, 7 and / or ferrules when the sensors 11, 12, 13 are pressure sensors. Indeed, the sensors 11, 12, 13 make it possible to measure pressures in several directions in the same vicinity, these pressures being due to air flows at the level of the turbomachine, and to deduce therefrom an angle of incidence of these as a function of the position of the device 4 relative to the blades 6, 7 and to the ferrules of the turbomachine. This measurement of the air flow angle is particularly useful during a development test of turbomachine parts.

In this case, the sensors 11, 12, 13 are capable of transmitting analog output signals which can be represented by pressure curves, portions 61, 62, 63, 71, 72, 73 of which are illustrated in FIG. 3.

The references 61 and 71 designate curve portions representing a first output signal -1 from a first sensor 11, the references 62 and 72 designate curve portions representing a second output signal -2 from a second sensor 12, and the references 63 and 73 designate portions of the curve representing a third signal

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- 10 -3 output from a third sensor 13. Each of the signals -1, -2, -3 can be broken down into periods comprising periods 61 and 71 for the signal -1, periods 62 and 72 for the signal - 2, and periods 63 and 73 for the signal -3. The periods common to the three signals are 61, 62 and 63 on the one hand, defining the period 6 *, and 71, 72 and 73 on the other hand, defining the period 7 *. The periods 6 * and 7 * correspond to the signals generated by the sensors when the blades 6 and 7 pass respectively. The offset 8 between two consecutive blades 6, 7 is of the order of approximately 100 ps, and the delay 612 or 613 between two signals -1 and -2, or -1 and -3 over the same period 6 * or 7 * is of the order of a few ps. The delays 612 and 613 are due to the phase shifts between the signals -1, -2, -3 consecutive to the location and the different orientation of the sensors 11, 12 and 13.

As shown in FIG. 3, the times 612 and 613 are able to be determined over the period 6 * as being the times of time separating a top of the portion 61 from a top of the portion 62 and the portion 63 respectively. Another common area of the signals -1, -2 and -3 over this period 6 * could have been used to determine these delays 612 and 613 without departing from the scope of the invention. This common area could be, for example, a hollow, an increasing or decreasing flank of the portions 61, 62 and 63.

During step (iii) of the method, the signals -2 and -3 are synchronized with the signal -1 by shifting them by the delays 612 and 613 respectively. Thus, the signals are brought back into the same time frame which simplifies their processing in step (iv) with a view to deducing a piece of test measurement information from the part.

In summary, the present invention relates to a measurement method for testing a part of an aircraft turbomachine on the basis of analog output signals from sensors 11, 13, 13, the method comprising a step of synchronization by a device analog of at

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- 11 minus some of these signals 61, 71, 62, 72, 63, 73 preceding a step of processing by an electronic device the synchronized signals.

The present invention has been described in relation to specific embodiments, which have a purely illustrative value and should not be considered as limiting. In general, it will be obvious to a person skilled in the art that the present invention is not limited to the examples illustrated and / or described above. The invention each includes new features and all of their combinations.

In the context of this document, the terms "first", "second", "third" and "fourth" serve only to differentiate between the different elements and do not imply an order between them. The use of the verbs "to understand", "to include", "to include", or any other variant, as well as their conjugations, cannot in any way exclude the presence of elements other than those mentioned. The use of the indefinite article "a", "an", or of the definite article "the", "the" or "the", to introduce an element does not exclude the presence of a plurality of these elements.

Claims (15)

1. Measurement method for a test of a part of an aircraft turbomachine comprising the following steps: (i) provide: - said part; - sensors (11; 12; 13) for measuring the same physical quantity, and able to supply analog signals corresponding to said same physical quantity; - an analog electronic preprocessing device coupled to said sensors (11; 12; 13) for preprocessing signals from said sensors (11; 12; 13); and - an electronic processing device coupled to said electronic preprocessing device to deduce at least one item of information related to said physical quantity; (ii) positioning said sensors (11; 12; 13) at separate locations to measure the same physical quantity influenced at least partially by said part at these different locations; (iii) synchronize analogically, and using the analog electronic device for preprocessing the analog signals (61,71; 62, 72; 63, 73) coming from said sensors (11; 12; 13); (iv) using the electronic processing device to process the signals (61, 71; 62, 72; 63, 73) synchronized in the previous step to deduce at least information related to said physical quantity and test information of said piece. BE2018 / 5281 2. Method according to the preceding claim, characterized in that step (iii) comprises a step of adding a delay (612; 613) to each of said signals (61,71; 62, 72; 63, 73) , said delay (612; 613) consisting of a positive, negative or zero time delay. 3. Method according to the preceding claim, characterized in that step (iii) comprises the following sub-steps: - choosing a reference signal (61, 71) from among said signals (61, 71; 62, 72; 63, 73); - identify a common area for each of said signals (61, 71; 62, 72; 63, 73); - determining said delay (612; 613) to be added to each of said signals (61, 71; 62, 72; 63, 73), said delay (612; 613) being a delay separating said common areas from said reference signal (61, 71) and said each of said signals (61, 71; 62, 72; 63, 73). 4. Method according to the preceding claim, characterized in that step (iii) comprises the following sub-steps: - decomposing each of said signals (61, 71; 62, 72; 63, 73) into a collection of periods (61; 62; 63; 71; 72; 73); - identify common periods (61, 62, 63; 71, 72, 73) for each of said signals (61, 71; 62, 72; 63, 73); - determining a variation for each of said common periods (61, 62, 63; 71, 72, 73) of each of said signals (61, 71; 62, 72; 63, 73), said variation consisting of a positive time variation, negative or zero, of said delay (612; 613) added to said each of said signals (61, 71; 62, 72; 63, 73); BE2018 / 5281 5. Method according to one of claims 3 or 4, characterized in that said common area identified for each of said signals (61, 71; 62, 72; 63, 73) consists of a vertex and / or a trough and / or a rising edge and / or a falling edge of a curve representing said each of said signals (61, 71; 62, 72; 63, 73). 6. Method according to any one of the preceding claims, characterized in that step (iii) consists in synchronization of said analog output signals. 7. Method according to any one of the preceding claims, characterized in that it comprises a step of recording said signals processed in step (iv). 8. Method according to any one of the preceding claims, characterized in that it comprises a step of detecting at least one defect in said part on the basis of said signals processed in step (iv). 9. Method according to any one of the preceding claims, characterized in that step (iii) is preceded by a step of setting in motion of said turbomachine. 10 ferrule (6, 7) of an aircraft turbomachine according to any one of the preceding claims. 10. Method according to any one of the preceding claims, characterized in that step (i) comprises a step of supplying pressure sensors (11, 12, 13). BE2018 / 5281 11. Method according to any one of the preceding claims, characterized in that step (i) comprises a step of supplying at least one device (4) comprising at least three sensors (11, 5 12, 13) positioned and oriented separately, and in that step (ii) comprises a step of positioning the at least one device (4) near said part. 12. Method of measurement for testing at least one blade and / or one 13. Method for measuring an angle of an air flow for a test at at least one blade and / or one shroud (6, 7) of a turbomachine - 14 - adding said variation to said each of said common periods (61, 62, 63; 71, 72, 73) of said each of said signals (61, 71; 62, 72; 63, 73). 15 aircraft according to any one of claims 10 or 11.