FR3111704A1 - DEVICE FOR MEASURING A PHYSICAL PARAMETER IN A TEST BENCH OF AN AIRCRAFT TURBOMACHINE, AND ASSOCIATED TEST BENCH - Google Patents

Abstract

DEVICE FOR MEASURING A PHYSICAL PARAMETER IN A TEST BENCH OF AN AIRCRAFT TURBOMACHINE, AND ASSOCIATED TEST BENCH The invention relates to a device (17) for measuring a physical parameter in a test bench (11) of an aircraft turbine engine (1), the device (17) comprising a sensor (18) having a generally elongated and comprising a first free end (18b) for measuring the parameter and a second end (18a) opposite the first free end (18b) and configured to be connected to a control unit, characterized in that it comprises in addition to a tubular adapter (19) extending longitudinally along an axis of elongation (X), this adapter (19) comprising an internal bore (19a) configured to receive the sensor (18) and to center and position it along of the elongation axis (X) so that its first free end (18b) remains free and has a predetermined axial position with respect to the adapter (19), the adapter (19) further comprising a external thread (20) configured to cooperate by screwing with a complementary internal thread e formed in an orifice (16) in the test bench (11). Abstract Figure: Figure 3

Description

DEVICE FOR MEASURING A PHYSICAL PARAMETER IN A TEST BENCH OF AN AIRCRAFT TURBOMACHINE, AND ASSOCIATED TEST BENCH

Technical field of the invention

The invention relates to the technical field of devices for measuring a physical parameter such as pressure or temperature in an aircraft turbomachine test bench.

The invention falls within the general technical field of aircraft turbomachines.

Technical background

An aircraft turbomachine comprises a fan allowing the suction of an air flow which is divided into a primary flow and a secondary flow. The primary flow flows in an annular primary stream of gas flow passing through the engine of the turbomachine while the secondary flow is directed to a secondary stream surrounding the primary stream.

The primary flow is compressed within, for example, a low pressure compressor then a high pressure compressor of the engine. The compressed air is then mixed with fuel and burned in an annular combustion chamber arranged downstream of the series of compressors. The gases formed by the combustion pass through a high pressure turbine and a low pressure turbine to drive the compressors, the turbines being located downstream of the combustion chamber. The gases finally escape through a nozzle whose section allows the acceleration of these gases to generate propulsion.

In order to ensure the good performance of a turbomachine, it must be tested on test benches.

A test bench is dedicated to a specific test objective. For example, the performance of the turbine or the high-pressure compressor is tested separately, in dedicated test benches.

For example, a low pressure turbine test bed includes a portion of the low pressure turbine. The test bench thus comprises an annular casing in which is formed at least one annular stream of main gas flow. The test bench further comprises at least one annular row of rotating blades surrounded by the casing. The tip of the blades and the casing radially delimit a chamber in which circulates part of the main flow of gas forming an intermediate flow of gas.

As part of the performance evaluation of the turbine, the efficiency between the main flow and the intermediate flow is for example quantified. For this purpose, one or more devices for measuring a parameter such as pressure or temperature are arranged in an orifice made in the test bench in order to quantify the intermediate flow in this chamber.

The measuring device generally comprises a sensor comprising a first free end for measuring the pressure or the temperature and a second opposite end connected to a control unit allowing the processing of the signal. Generally, this measuring device is fixed within the orifice by an adhesive, by a polymeric material formed for example of a cross-linked silicone or even by cement. The device is thus fixed in an irreversible manner within the cavity and in a random manner. This attachment of the device has many disadvantages.

Indeed, in order to evaluate the impact of the geometry of the chamber on the efficiency between the main and intermediate flow, the measurement of the pressure and the temperature must be carried out within chambers whose geometries have been modified between several measures. Thus, it is necessary to disassemble the test bench to modify the geometry of the chamber. The measuring device must then also be disassembled and then reassembled in the test bench to perform new parameter measurements.

However, the measuring device cannot be dismantled since it is irreversibly fixed in the cavity. The implementation of the test bench is thus limited to a single series of measurements corresponding to a given chamber geometry.

Also, the measuring device cannot be positioned precisely in the orifice, which affects the accuracy of the measurement of the parameters.

There is therefore a need to provide a measuring device making it possible to carry out a plurality of tests and to carry out precise measurements of various parameters.

To this end, the invention proposes a device for measuring a physical parameter in a test bench of an aircraft turbine engine, the device comprising a sensor having a generally elongated shape and comprising a first free end for measuring the parameter and a second end opposite the first free end and configured to be connected to a control unit.

The device is characterized in that it comprises a tubular adapter extending longitudinally along an axis of elongation, this adapter comprising an internal bore configured to receive the sensor and to center and position it along the axis of elongation so that its first free end remains free and has a predetermined axial position relative to the adapter, the adapter further comprising an external thread configured to cooperate by screwing with a complementary internal thread provided in an orifice in the test bench.

The measuring device thus comprises a sensor making it possible to measure a parameter in the test bed of the aircraft turbine engine. According to the invention, the sensor is received in an adapter making it possible to center and position the sensor with respect to the axis of the adapter. Furthermore, according to the invention, the adapter comprises an external thread configured to cooperate with an internal thread of an orifice of the test bench.

Thus, the adapter can be positioned precisely in the test bench, allowing the sensor to be positioned precisely, which is centered in the adapter.

Furthermore, the adapter cooperating by screwing with the test bench, the device is, according to the invention, removably mounted in the test bench. Consequently, it is possible according to the invention to remove the measuring device from the test bench, then reassemble it to perform a new series of measurements.

Consequently, the measuring device of the invention makes it possible to accurately measure one or more parameters in one or different test benches.

The device may include any of the following features, taken alone or in combination with each other:

- the adapter comprises at least a first axial portion forming a head for gripping and driving the adapter in rotation during screwing or unscrewing of the adapter, and a second axial portion comprising the external thread,

- the second axial portion is interposed axially between the first axial portion and a third portion located on the side of said free end of the sensor, the third portion having an outer diameter smaller than the outer diameters of the first axial axial portion and of the second axial portion ,

- the gripping head has a hexagonal cross-section,

- a tubular coupling of the male-male type extending along the axis of elongation of the adapter and being traversed axially by the sensor, the coupling comprising a first male part engaged in one end of the internal bore of the adapter opposite the free end of the sensor,

- a nut arranged coaxially around a second male part of the connector opposite the first male part of the connector,

- the sensor is secured to the fitting, in particular by brazing or welding,

- an annular seal extends around the axis of elongation and is arranged between the fitting and the adapter,

- the sensor is a pressure or temperature sensor.

The invention also relates to a test bench for an aircraft turbomachine, comprising an annular casing comprising at least one annular gas flow stream, the casing comprising at least one orifice, the test bench further comprising at least one measuring device as described above, the external thread of the adapter cooperating by screwing with a complementary internal thread of the orifice.

Brief description of figures

Other characteristics and advantages will emerge from the following description of a non-limiting embodiment of the invention with reference to the appended drawings in which:

Figure 1 is a schematic half view of an aircraft turbine engine,

Figure 2 is a schematic sectional view of an example of a test bench of a turbomachine according to the invention,

FIG. 3 is a perspective view of an element of the measuring device according to the invention,

Figure 4 is a longitudinal sectional view of the element of the measuring device of Figure 3,

FIG. 5 is a perspective view of an example of a measuring device according to the invention,

Figure 6 is a longitudinal sectional view of the measuring device of Figure 5.

Detailed description of the invention

A turbomachine 1 of an aircraft is for example represented in FIG. 1. The turbomachine 1 comprises a gas turbine engine extending along an axis A.

The engine has, upstream to downstream in the direction of flow of the gases F along the axis A, a fan 2, at least one compressor such as a low pressure compressor 3 and a high pressure compressor 4, a chamber combustion engine 5, at least one turbine such as a high pressure turbine 6 and a low pressure turbine 7, and a nozzle 8.

In the particular example of FIG. 1, the low pressure turbine 7 is connected to the fan 2 and to the low pressure compressor 3 by a low pressure shaft 10. The high pressure turbine 6 is itself connected to the high pressure compressor 4 by a high pressure shaft (not shown). The low pressure shaft 10 is arranged inside the high pressure shaft coaxially and extends along the axis A.

The blower 2 allows the suction of an air flow dividing into a primary flow F1 and a secondary flow F2. The primary flow F1 passes through the engine of the turbomachine 1 while the secondary flow F2 is directed towards a secondary stream.

The primary flow F1 is compressed within the low pressure compressor 3 then the high pressure compressor 4. The compressed air is then mixed with a fuel and burned within the combustion chamber 5. The gases formed by the combustion pass through the turbine high pressure 6 and low pressure 7. The gases finally escape through the nozzle 8 whose section allows the acceleration of these gases to generate propulsion.

The performance of the turbomachine 1 is tested within a test bench 11 represented for example in FIG. 2. The test bench 11 is for example a test bench for the low pressure 3 or high pressure 4 compressor, of the high pressure 6 or low pressure 7 turbine or any other part of the turbomachine 1.

The test bench 11 is in the example of figure 2 a test bench of the low pressure turbine 7.

The test bench 11 comprises an annular casing 12 comprising at least one annular gas flow vein forming a main flow corresponding to the primary flow F1. The annular casing 12 comprises an internal surface on which is arranged a coating 13 of an abradable material. The annular casing 12 is formed of a plurality of sections 12a fixed to each other. Fixing means such as bolts make it possible to fix the sections 12a of the annular casing 12 together.

The test bench 11 also comprises an annular row of vanes 14 arranged in the annular casing 12. According to the example of FIG. 2, the test bench 11 comprises a plurality of annular rows of vanes 14, for example at least one annular row of vanes 14 movable in rotation and at least one annular row of vanes 14 stationary.

The annular row of vanes 14 and the annular casing 12 are preferably arranged coaxially. The top of the blades 14 delimits with the internal surface of the annular casing 12 a chamber 15. A part of the gas flow of the annular stream forming a secondary flow flows into the chamber 15.

The test bench 11 also comprises at least one orifice 16 and preferably a plurality of orifices 16. In the example of FIG. 2, the orifice 16 is for example provided in the annular casing 12. The walls of the orifice 16 are thus formed by the annular casing 12. The orifice 16 passes radially through the annular casing 12 and opens into the chamber 15. The orifice 16 preferably has a circular section, and an internal diameter for example comprised between 5 .5mm and 6.5mm.

Furthermore, the orifice 16 has an internal thread (not shown).

In order to evaluate the performance of the turbine, it is important to measure the efficiency between the main flow in the annular casing 12 and the secondary flow in the chamber 15.

To this end, according to the invention, the test bench 11 comprises at least one device 17 for measuring a physical parameter. The physical parameter is for example a pressure, a temperature or any other relevant parameter. As shown by way of example in Figure 2, the test bench 11 comprises a plurality of measuring devices 17. The measuring device 17 is arranged in the orifice 16. When the test bench comprises a plurality of measuring devices 17, each orifice 16 includes a measuring device 17.

The measuring device 17 comprises a sensor 18 and an adapter 19.

The sensor 18 has a generally elongated shape. The sensor 18 comprises a first free end 18b for measuring the parameter and an opposite second end 18a configured to be connected to a control unit (not shown). The sensor 18 is for example a temperature sensor. According to this example, it is made up of a thermocouple. According to another example, the sensor 18 is a pressure sensor. It is for example formed of a pressure tube.

The adapter 19 is for example shown in Figures 3 and 4. The adapter 19 is tubular and extends longitudinally along an axis of elongation X. The adapter 19 comprises an internal bore 19a configured to receive the sensor 18, to center it and position it along the elongation axis X so that its first end 18b remains free in the orifice 16 and has a predetermined axial position with respect to the adapter 19.

In addition, the adapter 19 comprises an external thread 20 configured to cooperate by screwing with the complementary internal thread of the test bench 11, in particular of the orifice 16.

In particular, and as shown by way of example in Figures 3 and 4, the adapter 19 comprises at least a first axial portion 21a and a second axial portion 21b, and optionally a third axial portion 21c.

The first axial portion 21a forms a head for gripping and rotating the adapter 19 when it is screwed or unscrewed in the orifice 1. It thus facilitates the assembly and disassembly of the measuring device 17 in the test bench. test 11. As best seen in Figure 3, the gripping head has a cross section relative to the axis of elongation X of hexagonal shape. It is thus easily operable by conventional tools such as a split wrench.

Preferably, the second portion 21b comprises the external thread 20. The external thread 20 extends for example over the entire length of the second portion 21b. According to another example, the external thread 20 extends over part of the length of the second portion 21b, for example over half the length of the second portion 21b. Furthermore, the external diameter of the second portion 21b is for example between 4 and 5 mm.

Preferably, the adapter 19 comprises a third portion 21c located on the side of the first free end 18b of the sensor 18. The second portion 21b is interposed axially between the first portion 21a and the third portion 21c. The external diameter of the third portion 21c is smaller than the external diameter of the first portion 21a and of the second portion 21b. Preferably, the outer diameter of the second portion 21b is smaller than the outer diameter of the first portion 21a.

Thus, the first portion and the second portion form a first shoulder 22. The shoulder 22 forms a support surface for the measuring device 17 in the orifice 16.

As shown in Figure 2, preferably, a seal 16a is arranged on the bearing surface, between the first portion 21a and the second portion 21b. The seal 16a makes it possible to seal the assembly formed by the measuring device 17 and the orifice 16.

According to an embodiment of the measuring device 17 shown in Figures 4 and 5, the measuring device 17 further comprises a connector 23. The connector 23 cooperates with the adapter 19 and extends along the axis of elongation X of the adapter 19. The sensor 18 passes axially through the connector 23 and the adapter 19. More particularly, the first end 18b of the sensor is free and the second end 18a of the sensor 18 passes through the connector 23 to be connected to the control unit.

The connector 23 is tubular and is of the male-male type. As seen in Figure 6, the connector 23 thus comprises a first male part 23a and a second male part 23b opposite the first male part 23a. The first male part 23a is connected to the second male part 23b by an intermediate part 23c. The first male part 23a has an outer diameter smaller than the inner diameter of the intermediate part 23c. The first male part 23a and the intermediate part 23c thus form a shoulder 23d forming a bearing surface.

The first male part 23a is engaged in one end of the internal bore 19a of the adapter 19 opposite the first free end 18b of the sensor 18. The bearing surface rests on an external surface of the first axial portion 21a of the 'adapter. Thus, the first male part 23 cooperates with the first axial portion 21a of the adapter 19.

Preferably, the sensor 18 is secured to the connector 23. This makes it possible to maintain the sensor 18 in the adapter 19 at a pre-determined axial position and thus to increase the precision of the measurement. The sensor 18 is secured to the internal surface of the connector 23. The sensor 18 is for example secured to the second male part 23b of the connector 23. For example, the sensor 18 and the connector 23 are secured by brazing or by welding.

Advantageously, an annular seal 24 is arranged between the connector 23 and the adapter 19. The annular seal 24 extends around the axis of elongation X of the adapter 19. The annular seal 24 makes it possible to reinforce the seal of the measuring device 17. The annular seal 24 is for example formed of a metallic material such as copper. The annular seal 24 is for example a flat seal.

Furthermore, the measuring device 17 may further comprise a nut 25 cooperating with the connector 23. The nut 25 is for example arranged coaxially around the second male part 23b of the connector 23.

The connector 23 and the nut 25 allow maintenance of the measuring device 17. In the event of breakage for example of the sensor 18, it is possible to replace it by removing only the connector 23 to replace the sensor 18 without dismantling the device. measuring 17 as a whole.

Furthermore, advantageously, the test bench 11 further comprises a marker making it possible to identify the measuring device 17 and the associated orifice 16. The marker is for example a visual marking made both on the measuring device 17 and on a part of the casing 12, close to the orifice 16. The visual marking is for example an engraved character marking.

Thus, according to the invention, the measuring device 17 makes it possible to carry out measurements of parameters such as the pressure or the temperature in the test bench 11 in a precise manner. The measuring device 17 is also removable according to the invention and can thus be assembled and disassembled according to the needs of the test.

Claims (10)

Device (17) for measuring a physical parameter in a test bench (11) of an aircraft turbine engine (1), the device (17) comprising:
- a sensor (18) having a generally elongated shape and comprising a first free end (18b) for measuring the parameter and a second end (18a) opposite the first free end (18b) and configured to be connected to a control unit , characterized in that it further comprises:
- a tubular adapter (19) extending longitudinally along an axis of elongation (X), this adapter (19) comprising an internal bore (19a) configured to receive the sensor (18) and to center and position it along of the elongation axis (X) so that its first free end (18b) remains free and has a predetermined axial position with respect to the adapter (19), the adapter (19) further comprising a external thread (20) configured to cooperate by screwing with a complementary internal thread made in an orifice (16) in the test bench (11). Device according to Claim 1, characterized in that the adapter (19) comprises at least a first axial portion (21a) forming a head for gripping and driving the adapter (19) in rotation during screwing or unscrewing the adapter (19), and a second axial portion (21b) comprising the external thread (20). Device according to the preceding claim, characterized in that the second axial portion (21b) is interposed axially between the first axial portion (21a) and a third portion (21c) located on the side of the said free end (18b) of the sensor (18) , the third axial portion (21c) having an outer diameter smaller than the outer diameters of the first axial axial portion (21a) and of the second axial portion (21b). Device according to one of Claims 2 or 3, characterized in that the gripping head has a hexagonal cross-section. Device according to any one of the preceding claims, characterized in that it further comprises a tubular connector (23) of the male-male type extending along the axis of elongation (X) of the adapter (19) and being crossed axially by the sensor (18), the connector (23) comprising a first male part (23a) engaged in one end of the internal bore (19a) of the adapter (19) opposite the free end ( 18b) of the sensor (18). Device according to the preceding claim, characterized in that it further comprises a nut (25) arranged coaxially around a second male part (23b) of the connector (23) opposite the first male part (23a) of the connector (23 ). Device according to the preceding claim, characterized in that the sensor (18) is secured to the connector (23), in particular by brazing or welding. Device according to one of Claims 5 to 7, characterized in that an annular seal (24) extends around the elongation axis (X) and is arranged between the connector (23) and the adapter (19 ). Device according to any one of the preceding claims, characterized in that the sensor (18) is a pressure or temperature sensor. Test bench (11) for an aircraft turbine engine (1), comprising an annular casing (12) comprising at least one annular gas flow stream, the casing (12) comprising at least one orifice (16) , the test bench (11) further comprising at least one measuring device (17) according to one of claims 1 to 9, the external thread (20) of the adapter (19) cooperating by screwing with a thread internal complementary to the orifice (16).