TURBOMACHINE INCLUDING A BOUNDARY LAYER MEASUREMENT DEVICE

Abstract

The invention relates to a turbomachine extending about a longitudinal axis (X) and comprising: - a rotor driven in rotation about the longitudinal axis and having a radially external wall (28) intended to guide at least partially an aerodynamic flow; and - at least one measuring device (20) for parameters of the aerodynamic flow of the turbomachine (1), the measuring device comprising a body (21) extending radially with respect to the longitudinal axis and carrying means for acquiring information (22) relating to the parameters of the aerodynamic flow. According to the invention, the measuring device (20) is connected to a stator via a connecting element (30) configured such that a free end (23a) of the body (21) is opposite and close to the radially external wall and such that a portion of the connecting element is guided in rotation with respect to the radially external wall (28). Figure for the abstract: Figure 2

Description

Title of the invention: TURBOMACHINE COMPRISING A BOUNDARY LAYER MEASURING DEVICE Field of invention

[0001] The present invention relates to the general field of aeronautics. It relates, in particular, to a device for measuring at least one parameter of an aerodynamic flow of a turbomachine, this device being intended to cross an aerodynamic flow of the aircraft turbomachine. Technical background

[0002] In the context of the development of turbomachines, and in particular turbomachines for aircraft, these undergo a plurality of tests and trials making it possible to verify and validate, on the one hand, their proper functioning and, on the other hand, their capacity to maintain their integrity and their performances. The validation of these tests and trials makes it possible to obtain a certification authorizing their commissioning. In particular, during these tests and trials, measurements of certain aerodynamic flow parameters, such as pressure, temperature and / or acceleration, are carried out by means of a measuring device.

[0003] This measuring device is generally known as an intrusive meter or measuring comb. There are different types which are suitable for measuring one or more parameters of the flow and which are generally installed in one or more specific zone(s) of the turbomachine where the aerodynamic flow to be measured circulates, such as zones of an aerodynamic vein. These different zones are commonly called "measuring plane". Indeed, the aerodynamic flow circulating in a vein of the turbomachine has different characteristics in various zones of the vein, for example at the central zone thereof, along the walls delimiting the vein, upstream of stator blades, etc. Several devices may therefore be necessary for a complete mapping of the parameters of the flow in the vein.

[0004] A measuring device comprises an elongated body extending through the aerodynamic flow and equipped with means for recording information relating to the parameters of the flow. Such a device is described for example in documents FR-A1-2952713 and FR-A1-3067454. It is known from these examples that the measuring devices are generally fixed to the stator of the turbomachine. However, these measuring devices do not make it possible to obtain a measurement as close as possible to the various components and for example for a measurement of the boundary layer circulating close to the rotor.

[0005] There is a need to resolve all or part of the aforementioned drawbacks. Summary of the invention

[0006] The objective of the present invention is to provide a simple and economical solution for carrying out measurements of at least one parameter of a turbomachine aerodynamic flow near a rotor.

[0007] We achieve this objective in accordance with the invention by means of a turbomachine extending around a longitudinal axis and comprising:

[0008] - a rotor driven in rotation around the longitudinal axis and having a ra- wall externally intended to guide at least in part an aerodynamic flow; and, - at least one device for measuring parameters of the aerodynamic flow of the turbomachine, the measuring device comprising a body which extends radially relative to the longitudinal axis and which carries means for recording information relating to the parameters of the aerodynamic flow, the measuring device being connected to a stator via a connecting element configured so that a free end of the body is opposite and close to the radially external wall and in that a portion of the connecting element is guided in rotation relative to the radially external wall.

[0009] Thus, this solution makes it possible to achieve the aforementioned objective. In particular, the connecting element fixed to the stator of the turbomachine makes it possible to carry at least one measuring device which is placed as close as possible to the rotor, which rotates relative to the measuring device, to measure the air flow at the boundary layer, with minimal disturbance, and while avoiding the transmission of forces to the stator. This configuration also makes it possible more precisely to avoid the generation of forces on the surrounding parts of the turbomachine and on the measuring device itself. The measurements obtained such as the pressure are reliable. Added to this is the fact that integrating the measuring device into the turbomachine by fixing it to the stator and being "suspended" is simpler than fixing it to the rotor. Fixing it to the rotor could also induce errors in reading the measurements.

[0010] The turbomachine also comprises one or more of the following features, taken alone or in combination:

[0011] - the body has a height between 2% and 5% of the height of the vein measured from the radially outer wall of the rotor to a radially inner wall of the stator.

[0012] - the connecting element comprises an arm extending radially towards the wall ra radially external, the arm cooperating with a support and rotational guidance device mounted on the radially external wall.

[0013] - the guide device comprises a roller, an air cushion or a positioning system- magnetic servo-controlled operation.

[0014] - the connecting element comprises a portion extending radially around the wall radially external, the measuring device being fixed to a free end of the portion.

[0015] - the body of the measuring device comprises a leading edge and a trailing edge opposite along the longitudinal axis, the information collection means extending from the leading edge along the longitudinal axis.

[0016] The invention further relates to an aircraft equipped with such a turbomachine. Brief description of the figures

[0017] The invention will be better understood, and other aims, details, characteristics and advantages thereof will appear more clearly on reading the detailed explanatory description which follows, of embodiments of the invention given as purely illustrative and non-limiting examples, with reference to the appended schematic drawings in which:

[0018] [Fig.l] schematically represents, in axial and partial section, an example of a double-flow turbomachine to which the invention applies;

[0019] [Fig.2] illustrates schematically and in a front view an example of a measuring device installed in a turbomachine according to the invention.

[0020] [Fig.3] is a side view of the measuring device according to [Fig.2]; and

[0021] [Fig.4] is a view from one side of the measuring device according to [Fig.2]. Detailed description of the invention

[0022] [Fig.l] shows a partial axial sectional view of a turbomachine with longitudinal axis X, in particular a double-flow turbomachine 1 intended to be mounted on an aircraft. Of course, the invention is not limited to this type of turbomachine and can be a single-flow turbojet or a turboprop equipped with a single unducted propeller or a pair of counter-rotating, unducted propellers.

[0023] The turbomachine 1 of [Fig.l] comprises, in a conventional manner and, from upstream to downstream, a fan 2, a low-pressure compressor 3, a high-pressure compressor 4, an annular combustion chamber 5, a high-pressure turbine 6, a low-pressure turbine 7. An exhaust nozzle 8 is advantageously arranged downstream of the low-pressure turbine 7. The high-pressure compressor 4 and the high-pressure turbine 6 are connected by a high-pressure shaft and form with it a high-pressure (HP) body. The low-pressure compressor 3 and the low-pressure turbine 7 are connected by a low-pressure shaft and form with it a low-pressure (LP) body.

[0024] In the present invention, the terms “upstream” and “downstream” are defined in relation to the circulation of gases in the turbomachine and here along the longitudinal axis X. Similarly, the terms “radial”, “internal” and “external” are defined in relation to an axis radial Z perpendicular to the longitudinal axis X and with respect to the distance from the longitudinal axis X.

[0025] The turbomachine 1 comprises a first annular vein, called primary vein 9 in which circulates a primary aerodynamic flow Fl or hot flow and a second annular vein, called secondary vein 10 in which circulates a secondary aerodynamic flow F2 or cold flow around the primary vein 9. The primary flow Fl passes through the compressors, the combustion chamber, and the turbines, then opens into the nozzle 8 towards the atmosphere.

[0026] The primary and secondary veins 9, 10 are coaxial. In particular, the primary vein 9 is delimited radially by an annular internal casing 11 and an inter-vein casing 12 surrounding the internal casing. As for the secondary vein 10, this is delimited radially by the inter-vein casing 12 and an annular external casing 13 to which a fan casing 14 is secured. The latter surrounds the blades 15 of the fan 2.

[0027] The turbomachine 1 comprises at least one device 20 for measuring parameters of an aerodynamic flow F1, F2 which is provided for measuring one or more parameters of the aerodynamic flow circulating in the turbomachine so as to establish a map of the pressures, temperatures, accelerations, and / or the composition of said flow in the vicinity of the measuring device 20. These parameters are necessary to obtain certification of the turbomachine before its marketing for example or to verify the state of health of the turbomachine. The measurement is said to be intrusive because it is carried out directly in the flow of the aerodynamic flow.

[0028] Advantageously, the measuring device 20 is intended to be installed substantially radially in one of the primary and secondary veins 9, 10 of the turbomachine.

[0029] According to yet another advantageous characteristic, the measuring device 20 is arranged upstream of the fan 2. Advantageously, the measuring device 20 is arranged along the radial axis and transversely to the flow of the air flow F entering the turbomachine. The air flow F is separated downstream of the fan into the primary flow F1 and the secondary flow F2.

[0030] With reference to figures 2 and 3, the measuring device 20 comprises a body 21 and information recording means 22 configured to record information relating to at least one parameter of the aerodynamic flow flowing in the turbomachine.

[0031] Preferably, the measuring device 20 is configured to measure the pressure of the aerodynamic flow F1, F2.

[0032] The body 21 is elongated and extends in a direction of elongation A between a first end 23a and a second end 23b. As we can also see in [Fig.3], the body 21 has a leading edge 24a and a trailing edge 24b opposite transversely to the direction of elongation A. The leading edge 24a and the trailing edge 24b respectively connect two lateral faces 25a, 25b opposite in a transverse direction (or circumferential in the installation situation). This direction is perpendicular to the direction of elongation A.

[0033] The body 21 may have an oblong cross-section or alternatively a NACA type cross-section (the initials of which stand for "National Advisory Committee for Aeronautics"). In the latter case, the opposite side faces 25a, 25b thus meet at an edge at the trailing edge 24b.

[0034] The body 21 advantageously carries the information collection means 22. These extend transversely to the direction of elongation A of the body 21 and here parallel to the longitudinal axis X (and to the flow of the aerodynamic flow).

[0035] In [Fig. 3], the information collection means 22 are arranged at the leading edge 24a of the body 2. These are also arranged and distributed regularly along the leading edge 24a (either along the radial axis Z or along the direction of elongation of the body). The information collection means 22 are advantageously connected to means (not shown) for conveying the information collected by the information collection means.

[0036] The turbomachine 1 is advantageously equipped with an information processing system 50 which is illustrated in [Fig.l] schematically. The information processing system 50 is connected to the routing means.

[0037] In the present example, the information collection means 22 comprise nozzles 26. Each nozzle 26 has a substantially cylindrical shape and extends from the leading edge 24a. The nozzles 26 are regularly distributed along the leading edge 24a. Each nozzle 26 communicates with a longitudinal cavity 27 arranged in the body 21 of the measuring device 20. The longitudinal cavity 27 passes through the body of the measuring device 20 on either side and opens at the first and second ends 23a, 23b. Each nozzle 26 comprises an inlet orifice which is exposed to the aerodynamic flow to take a sample therefrom.

[0038] In the present embodiment, the measuring device 20 is connected to a stator of the turbomachine. The measuring device 20 also cooperates with a rotor of the turbomachine. The rotor is rotated relative to the stator.

[0039] The stator of the turbomachine 1 is advantageously a casing of the turbomachine such as the fan casing 14 or the external casing 13 (or nacelle carried by the fan casing). The stator of the turbomachine could also be an element of the frame of a test bench of an unducted turbomachine or an element of the frame of the turbomachine.

[0040] The rotor of the turbomachine is advantageously formed from the rotor of the fan. The latter is driven by the low pressure shaft.

[0041] With reference to [Fig.3] and advantageously, the fan rotor comprises a hub 16 and an air inlet cone 17. The latter element may consist of a point or a more rounded shape.

[0042] In particular and as shown in [Fig. 2], the hub 16 is centered on the longitudinal axis X. The hub 16 carries a series of fan blades 15 which are distributed regularly around the longitudinal axis X. Each blade 15 extends radially from the hub 16 outwards. The free ends of the blades 15 are opposite the fan casing 14.

[0043] In [Fig. 3], the air inlet cone 17 is rotationally fixed to the hub 16. The air inlet cone 17 is mounted upstream of the hub 16 and covers it. Advantageously, the air inlet cone 17 is centered on the longitudinal axis X and has an axisymmetric shape.

[0044] Advantageously, the rotor (here the air inlet cone 17 and the hub 16) is driven in rotation relative to the measuring device 20. The latter is advantageously arranged as close as possible to a radially external wall 28 of the rotor.

[0045] For this, the turbomachine 1 is advantageously equipped with a connecting element 30 which is integral with the stator of the turbomachine 1. This connecting element 30 makes it possible to connect the measuring device 20 to the stator. More precisely, the connecting element 30 is configured so that a free end of the body 21 of the measuring device 20 is opposite and close to the radially external wall 28 and that a portion of the connecting element 30 is guided in rotation relative to the radially external wall 28.

[0046] Advantageously, but not limitatively, the connecting element 30 comprises a first end 30a which is fixed to the second end 23b of the body 21 of the measuring device 20.

[0047] The connecting element 30 also comprises a second end 30b which is fixed to the stator. The second end 30b is removably fixed using fixing members 31 such as screw / nut systems.

[0048] The first end 30a is advantageously, but not limited to, removably fixed to the body 21 of the measuring device 20. The fixing is carried out using welding or fixing members such as screws, nuts.

[0049] The rotor is, in other words, driven in rotation relative to the connecting element 30.

[0050] According to the embodiment illustrated in Figures 2 and 3, the connecting element comprises a first portion 32 which extends around the radially external wall 28 of the rotor (i.e. in the circumferential direction). In other words, the first portion 32 is substantially curved.

[0051] The connecting element 30 further comprises a second portion 33 which is connected to the first portion 32 and which is in the form of a pole which crosses the aerodynamic flow.

[0052] The first portion 32 comprises the first end 30a while the second portion 33 comprises the second end 30b. The measuring device 20 is located at the free end 30a of the first portion 32.

[0053] Several measuring devices 30 can be arranged regularly around the longitudinal axis X and carried by one or more connecting elements 30.

[0054] Advantageously, but not limitatively, the first end 30a of the connecting element 30 is located at a radial distance corresponding substantially to the height H1 of the body 21 of the measuring device 20. However, the first (free) end 23a of the measuring device 20 is not in contact with the rotor. In this way, the rotor can rotate freely without obstacle.

[0055] According to an advantageous characteristic, the height H1 of the body 21 is between 2% and 5% of the height H of the vein (primary or secondary 9, 10) measured from the external wall 28 of the rotor. This configuration makes it possible to measure the aerodynamic flow of the boundary layer which extends along the walls of the veins.

[0056] The height H, here of the secondary vein 10) is preferably measured between the radially external wall 28 of the rotor and a radially internal wall 29 of the stator, here the fan casing 14.

[0057] The connecting element 30 advantageously comprises an arm 34 extending radially towards the radially external wall 28. The arm 34 extends parallel to the measuring device 20 and at a distance therefrom. The arm 34 comprises a free end 34a facing the radially external wall 28.

[0058] Between the radially external wall 28 and the free end 34a of the arm 34 is arranged a guide device 35.

[0059] The guide device 35 is advantageously fixed to the radially external wall 28 of the rotor or to the free end of the measuring device 20. In the present example, the guide device 35 is fixed to the rotor, and in particular to the radially external wall 28. This makes it possible to create support on the rotor without transmitting force and to position the measuring device 20 as close as possible to the rotor. The measuring device 20 provides, among other things, a degree of freedom to the connecting element 30.

[0060] The guiding device 35 may comprise a roller, an air cushion or a servo-controlled magnetic positioning system.

[0061] Thus, such a configuration makes it possible to place the measuring device 20 as close as possible to the rotor, and in particular in the boundary layer and without transmission of forces. towards the stator to which the measuring device is attached.

Claims

Claims

1. Turbomachine (1) extending around a longitudinal axis (X) and comprising: - a rotor (16, 17) driven in rotation around the longitudinal axis (X) and having a radially external wall (28) intended to guide at least in part an aerodynamic flow (F, F1, F2), and - at least one device (20) for measuring parameters of the aerodynamic flow of the turbomachine (1), the measuring device (20) comprising a body (21) which extends radially with respect to the longitudinal axis (X) and which carries means for recording information (22) relating to the parameters of the aerodynamic flow (F, F1, F2), characterized in that the measuring device (20) is connected to a stator (13, 14) via a connecting element (30) configured so that a free end (23a) of the body (21) is opposite and close to the radially external wall (28) and in that a portion of the connecting element (30) is guided in rotation relative to the radially external wall (28).

2. Turbomachine (1) according to the preceding claim, characterized in that the body (21) has a height (Hl) of between 2% and 5% of the height of the vein (H) measured from the radially external wall (28) of the rotor (16, 17) to a radially internal wall (29) of the stator (13, 14).

3. Turbomachine (1) according to claim 1 or 2, characterized in that the connecting element (30) comprises an arm (34) extending radially towards the radially external wall (28), the arm cooperating with a rotational support and guide device (35) mounted on the radially external wall (28).

4. Turbomachine (1) according to the preceding claim, characterized in that the guide device (35) comprises a roller, an air cushion or a servo-controlled magnetic positioning system.

5. Turbomachine (1) according to any one of the preceding claims, characterized in that the connecting element (30) comprises a portion (32) extending radially around the radially external wall (28), the measuring device (20) being fixed to a free end of the portion (32).

6. Turbomachine (1) according to one of the preceding claims, characterized in that the body (21) of the measuring device (20) comprises a leading edge (24a) and a trailing edge (24b) opposite each other along the longitudinal axis (X), the information recording means (22) extending from the leading edge (24a) along the longitudinal axis (X).

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