ASSEMBLY FOR A TURBOMACHINE INCLUDING A VARIABLE-PITCHING BLADE AND A MEASURING DEVICE
A dynamic measuring device integrated with a variable-pitch blade in turbomachines addresses measurement challenges by moving with the blade, ensuring accurate airflow parameter measurement and overcoming the limitations of static devices.
Patent Information
- Application Number
- FR2023008417
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-08-03
- Publication Date
- 2026-03-06
- Estimated Expiration
- 2043-08-03
AI Technical Summary
Existing turbomachines with unshrouded fans face challenges in accurately measuring airflow parameters due to turbulence caused by static measuring devices, which are not applicable and distort results, and cannot measure parameters near moving elements like the fan cone or disk without risking collision.
A dynamic measuring device is integrated with a variable-pitch blade, moving in conjunction with it to avoid disturbing the aerodynamic and mechanical behavior, allowing precise measurement of airflow parameters, including those near the fan cone or disk.
The solution ensures accurate airflow parameter measurement without disturbing the blade's behavior, eliminating the need for a fixed element and enabling boundary layer parameter measurement, thus improving measurement precision and reliability.
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Abstract
Description
Title of the invention: ASSEMBLY FOR A TURBOMACHINE INCLUDING A VARIABLE-PITCHING BLADE AND A MEASURING DEVICE Technical field of the invention
[0001] The present invention relates to an assembly for a turbomachine comprising a variable-pitch blade and a measuring device, as well as a turbomachine comprising such an assembly. Technical background
[0002] In the context of the development of a turbomachine, engine manufacturers carry out various tests aimed at measuring parameters (pressure, temperature, etc.) specific to each of the flows flowing in the turbomachine during the different operating regimes (takeoff, cruise, thrust reversal, etc.), with the aim in particular of validating or not certain technical solutions put in place.
[0003] To measure these flow-specific parameters, it is known to install intrusive measuring devices, more commonly called "combs" because of their shape, in each of the flows studied. A measuring device is typically mounted on a fixed (or static) element of the turbomachine, such as the fan casing or the nacelle.
[0004] Thus, to measure the airflow parameters upstream of a shrouded fan, it is common practice to mount the measuring device on the fixed housing surrounding the fan. However, such a practice cannot be applied to turbomachinery with an unshrouded fan since there is no fixed element near the fan that could be used to support the measuring device.
[0005] By way of example, a turbomachine known by the English acronym "USF" for "Unducted Single Fan" includes such an unducted fan.
[0006] Engine manufacturers also note that a static measuring device mounted opposite a moving element (for example, the fan) generates turbulence that inevitably disturbs the aerodynamic and mechanical behavior of that moving element. This disturbance thus distorts the results obtained, without being able to precisely quantify the inaccuracy of the results.
[0007] Engine manufacturers also note that static measuring devices do not allow for the measurement of parameters (pressure, temperature, etc.) of the boundary layer formed in the immediate vicinity of the fan cone or disk. Indeed, sufficient clearance must be maintained between a static measuring device and a moving element to to avoid any collision, as the parts are prone to deformation when the turbomachine is in operation.
[0008] The objective of the present invention is therefore to provide a simple, effective and economical solution to address the aforementioned problems. Summary of the invention
[0009] The invention thus proposes an assembly for a turbomachine comprising: - a variable pitch blade of an unfaired fan comprising an aerodynamic blade and a base intended to be mounted in a socket of a pivot; - a measuring device comprising an aerodynamic body which is adjacent to the blade and disposed upstream of the blade, the body carrying at least one measuring instrument configured to measure at least one parameter of an airflow upstream of the blade, the measuring device being configured to be attached to the blade and / or the pivot, so that the measuring device moves jointly with the blade, so as not to disturb the aerodynamic and mechanical behavior of the blade.
[0010] Unlike the prior art, the measuring device here is dynamic and moves in conjunction with the blade, which offers the following advantages: - the aerodynamic and mechanical behavior of the blade (and more generally of the fan) is not disturbed; - the fixing of the measuring device does not require the presence of a fixed element near the blower; - the measuring device can be used to measure the parameters of the boundary layer formed in the immediate vicinity of the cone or disk of the blower.
[0011] The measuring device can be attached only to the blade, only to the pivot or to both.
[0012] The assembly according to the invention may include one or more of the features, taken individually or in combination with each other: - the measuring device and the blade are distinct from each other, the measuring device comprising a foot connected to the body, the foot of the measuring device being intended to be mounted jointly with the foot of the blade in the pivot socket; - the measuring device is mounted on an extension of the base of the blade; - the extension includes a through hole for the passage of the measuring instrument; - the body comprises a leading edge and a trailing edge connected to each other by two lateral walls; - the body is oriented relative to the blade, so as to guide the airflow exiting the trailing edge towards an extrados face of the blade; - the trailing edge of the body coincides with a leading edge of the blade; - the body includes a leading edge from which two wings extend opposite each other, the wings overlapping the intrados and extrados faces of the blade; - the body includes at least one tube projecting from the leading edge, the tube having an inlet orifice at its free end, the tube forming a housing in which the measuring instrument is received.
[0013] The present invention also relates to a turbomachine comprising an unfaired blower which includes the assembly as described above, the foot of the blade being mounted in a recess of a pivot of the blower, the measuring device being integral with the blade and / or the pivot. Brief description of the figures
[0014] The invention will be better understood and other details, features and advantages of the invention will become more apparent upon reading the following description, given by way of non-limiting example and with reference to the accompanying drawings in which:
[0015] [Fig-1] [Fig.1] is a schematic longitudinal half-section view of a turbomachine comprising an assembly according to a first embodiment of the invention, the assembly comprising a variable pitch blade and a measuring device;
[0016] [Fig.2] [Fig.2] is a schematic exploded view of a detail of [Fig.1];
[0017] [Fig.3] [Fig.3] is a side view of the assembly illustrated in [Fig.1];
[0018] [Fig.4] [Fig.4] is a top view of the assembly illustrated in [Fig.1];
[0019] [Fig.5] [Fig.5] is a first perspective view of the assembly illustrated on the [Fig.l];
[0020] [Fig.6] [Fig.6] is a second perspective view of the assembly illustrated in [Fig.1];
[0021] [Fig.7] [Fig.7] is a first perspective view of an assembly according to a second embodiment of the invention;
[0022] [Fig.8] [Fig.8] is a second perspective view of the assembly illustrated in [Fig.7], an upstream part of the extension of the foot of the blade being hidden to illustrate the mounting of the measuring device on the extension. Detailed description of the invention
[0023] Figure 1 schematically represents a turbomachine 1 with longitudinal axis X. The turbomachine 1 comprises an unducted propulsive fan 2 and an unducted fixed stator 3. Such a turbomachine 1 is more commonly known by the English acronym USF for "Unducted Single Fan".
[0024] As illustrated in [Fig. 1], the fan 2 is driven in rotation about the X-axis by a motor 4 located downstream of the fan 2. Such an arrangement of the turbomachine 1 is more commonly known as a "tractor" or "puller." "In English. In such an arrangement, the rectifier 3 is positioned longitudinally downstream of the blower 2.
[0025] The example illustrated in [Fig.1] is in no way limiting; the turbomachine could, for example, include an unfaired fan located downstream of the engine, or two unfaired counter-rotating fans located upstream or downstream of the engine.
[0026] The turbomachine 1 is defined along the longitudinal axis X which corresponds to the axis of rotation of the fan 2.
[0027] The engine 4 here comprises a gas generator and at least one power turbine (or low-pressure turbine) intended to drive the fan 2 in rotation. The fan 2 can be driven in rotation by the power turbine via a speed reducer. The gas generator conventionally comprises, from upstream to downstream, at least one compressor, a combustion chamber, and at least one expansion turbine (or high-pressure turbine). The compressor and the expansion turbine are rotationally coupled to each other via a drive shaft. The gas generator is supplied with air by an air inlet 5 which opens between the fan 2 and the rectifier 3.
[0028] The blower 2 generates a propulsive airflow F which flows upstream to downstream around the outer fairings of the streamlined body 6 of the turbomachine 1, a minor part of this flow F being taken by the air inlet 5 to supply the gas generator.
[0029] By convention in this application, the terms "upstream" and "downstream" are defined with respect to the direction of airflow F.
[0030] Similarly, by convention in the present application, "longitudinal" or "longitudinally" means any direction parallel to the X-axis of the turbomachine 1, and "radial" or "radially" means any direction perpendicular to the X-axis of the turbomachine 1.
[0031] As illustrated in [Fig.1], the blower 2 comprises a disk 7 carrying an annular row of variable-pitch blades 8, each blade 8 being pitched around a rotation axis Y which is its own and which is substantially perpendicular to the axis X.
[0032] As illustrated in the figures, each variable pitch blade 8 comprises an aerodynamic (or profiled) blade 9 and a foot 10 intended to be mounted in a cavity 11 of a pivot 12 of the blower 2.
[0033] The blade 9 extends along a stacking axis from the foot 10 to a top 13. Each blade 9 comprises an intrados face 14 and an extrados face 15 connected to each other by a leading edge 16 and a trailing edge 17. The leading edge 16 is positioned upstream of the trailing edge 17. The leading and trailing edges 16, 17 are each in the form of a rounded shape.
[0034] The foot 10 has a constant cross-section and extends along an elongation axis which is substantially perpendicular to the stacking axis.
[0035] The foot 10 can be in cross-section, for example, in the form of a bulb, a dovetail, or a fir tree. The foot 10 is obtained, for example, by pinning. The recess 11 of the pivot 12 has a shape complementary to that of the foot 10 to allow its assembly.
[0036] As illustrated in [Fig. 1], the pivot 12 associated with each blade 8 is movably mounted about the Y-axis in a housing 18 of the disk 7 via two roller bearings. The disk 7 is annular about the X-axis and can be a single piece or formed of two half-disks joined together. The disk 7 is driven by the power turbine via a power shaft 19 centered on the X-axis and a transmission member 20 rotationally coupled to both the power shaft 19 and the disk 7. The blower 2 also includes an inlet cone 21 which is fixed to the disk 7.
[0037] As illustrated in [Fig. 1], the blower 2 includes a control system 22 for the pitch of the blades 8, better known by the English acronym PCM for "Pitch Change Mechanism". The control system 22 may, for example, include an actuator 23 common to all the blades 8 and a mechanism 24 specific to each of the blades 8, this mechanism 24 transforming the movement initiated by the actuator 23 into a rotational movement of the corresponding blade 8. The movement of the actuator 23 allows for the synchronized adjustment of the pitch of all the blades 8 via, in particular, the various mechanisms 24.
[0038] According to the invention, a measuring device 25 is associated with at least one of the variable pitch blades 8 of the blower 2.
[0039] The turbomachine 1 can obviously include several measuring devices 25, each measuring device 25 being associated with a variable pitch blade 8.
[0040] Advantageously, when the blower 2 includes several measuring devices 25, the measuring devices 25 are distributed regularly around the X axis, so as to have a balanced blower, and in other words avoid imbalances.
[0041] A measuring device 25 comprises an aerodynamic (or profiled) body 26 which is adjacent to the blade 9 of the associated vane 8 and disposed upstream of this blade 9. The body 26 carries at least one measuring instrument 27 (visible in [Fig. 2]) configured to measure at least one parameter (pressure, temperature, etc.) of the airflow F upstream of the blade 9. The measuring device 25 is configured to be fixed to the vane 8 and / or the pivot 12, so that the measuring device 25 moves in conjunction with the vane 8, in particular so as not to disturb the aerodynamic and mechanical behavior of the vane 8.
[0042] The body 26 of each measuring device 25 can obviously comprise several measuring instruments 27, each measuring instrument 27 being configured to measure one or more parameters of the airflow F upstream of the blade 9. The or The measuring instruments 27 are for example pressure sensors (pressure) and / or thermocouples (temperature).
[0043] Securing the measuring device 25 to the blade 8 (which is fixed to the pivot 12) or directly to the pivot 12 allows the measuring instruments 27 or the associated cables to be routed through the pivot 12. This avoids the need for one or more extra length loops which could not be fixed in any case and which would be damaged or come loose during the rotation of the blower.
[0044] According to the first embodiment illustrated in figures 1 to 6, the measuring device 25 is mounted on an extension 28 of the foot 10 of the blade 8. The extension 28 of the foot 10 extends in line with its main portion 29 located under the blade 9.
[0045] The measuring device 25 comprises a foot (not visible in figures 1 to 6) and a body 26 which extends radially from this foot.
[0046] More specifically, the body is slightly inclined upstream. The body 26 comprises a leading edge 30 and a trailing edge 31 connected to each other by two lateral walls 32. The leading edge 30 is located upstream of the trailing edge 31. The leading and trailing edges 30 and 31 are each rounded. The trailing edge 31 of the body 26 coincides with the leading edge 16 of the blade 9.
[0047] The body 26 is arranged upstream of the blade 9 and is oriented with respect to the blade 9, so as to guide the airflow F exiting the trailing edge 31 towards the extrados face 15 of the blade 9.
[0048] The body 26 includes one or more internal cavities (not visible in figures 1 to 6) to allow the passage of the measuring instrument(s) 27.
[0049] The body 26 comprises, for example, five tubes 33 projecting from the leading edge 30. The tubes 33 are spaced radially from one another at regular intervals. Each tube 33 has an inlet orifice 34 at its free end. The tubes 33 have different lengths so that the various inlet orifices 34 are radially aligned. Each tube 33 forms a housing in which one or more measuring instruments 27 can be received, each tube 33 being connected with at least one internal cavity of the body 26. The various tubes 33 are here located in the immediate vicinity of the cone 21 and the disk 7, to measure the parameters of the airflow F at the level of its boundary layer.
[0050] The foot of the measuring device 25 is mounted in a groove formed in the extension 28, the groove having a shape that is complementary to that of the foot to allow its mounting. The foot of the measuring device 25 is, for example, in the form of a dovetail, so as to withstand the centrifugal forces to which it is subjected when the turbomachine is in operation.
[0051] The extension 28 includes a through hole 35 for the passage of the measuring instrument(s) 27. The through hole 35 is formed partly in a bulge 36 which protrudes upstream of the extension 28.
[0052] The measuring device 25 is here fixed to the blade 8 and moves jointly with the blade 8 when its positioning is changed.
[0053] According to the second embodiment illustrated in figures 7 and 8, the measuring device 25 is also mounted on an extension 28 of the foot 10 of the blade 8.
[0054] The measuring device 25 comprises a foot 37 (visible in [Fig.8]) and a body 26 which extends radially from this foot 37.
[0055] More specifically, the body 26 includes a leading edge 30 from which two wings 38 extend opposite each other, the wings 38 overlapping the intrados and extrados faces 14, 15 of the blade 9.
[0056] The body 26 includes an internal cavity 39 to allow the passage of the measuring instrument(s).
[0057] The body 26 comprises, for example, two tubes 33 projecting from the leading edge 30. Each tube 33 has an inlet orifice 34 at its free end. Each tube 33 forms a housing in which one or more measuring instruments can be received, each tube 33 being connected with the internal cavity 39 of the body 26. The two tubes 33 are here located in the immediate vicinity of the cone 21 and the disk 7, to measure the parameters of the airflow F at the level of its boundary layer.
[0058] The foot 37 of the measuring device 25 is mounted in a groove 40 formed in the extension 28, the groove 40 having a shape complementary to that of the foot 37 to allow its mounting. The foot 37 of the measuring device 25 is in the form of a dovetail, so as to withstand the centrifugal forces to which it is subjected when the turbomachine is in operation.
[0059] The extension 28 includes a through hole 35 for the passage of the measuring instrument(s). The through hole 35 is formed partly in a bulge 36 which projects upstream of the extension 28.
[0060] The measuring device 25 is here fixed to the blade 8 and moves jointly with the blade 8 when its positioning is changed.
[0061] According to an embodiment not shown, the measuring device 25 and the associated blade 8 are separate from each other. The measuring device 25 comprises a foot connected directly or indirectly to the body, this foot of the measuring device 25 being mounted together with the foot 10 of the associated blade 8 in the recess 11 of the corresponding pivot 12. The measuring device 25 is here fixed to the pivot 12 and moves together with the blade 8 (the blade 8 is also fixed to the pivot 12) when its position is changed.
[0062] Advantageously, the foot of the measuring device 25 and the foot 10 of the blade 8 have identical dimensional and geometric characteristics.
[0063] The body of such a measuring device 25 may have the characteristics of the body 26 of the measuring device 25 according to the first embodiment and / or the characteristics of the body 26 of the measuring device 25 according to the second embodiment.
Claims
Demands
1. Assembly for a turbomachine (1) comprising: - a variable pitch blade (8) of an unfaired fan (2) comprising an aerodynamic blade (9) and a foot (10) intended to be mounted in a recess (11) of a pivot (12); - a measuring device (25) comprising an aerodynamic body (26) which is adjacent to the blade (9) and disposed upstream of the blade (9), the body (26) carrying at least one measuring instrument (27) configured to measure at least one parameter of an airflow (F) upstream of the blade (9), the measuring device (25) being configured to be integral with the blade (8) and / or the pivot (12), so that the measuring device (25) moves jointly with the blade (8), in order not to disturb the aerodynamic and mechanical behavior of the blade (8), the measuring device (25) being mounted on an extension (28) of the foot (10) of the blade (8).
2. Assembly according to claim 1, characterized in that the extension (28) includes a through hole (35) for the passage of the measuring instrument (27).
3. Assembly according to any one of the preceding claims, characterized in that the body (26) comprises a leading edge (30) and a trailing edge (31) connected to each other by two side walls (32).
4. Assembly according to the preceding claim, characterized in that the body (26) is oriented with respect to the blade (9), so as to guide the airflow (F) exiting the trailing edge (31) towards an extrados face (15) of the blade (9).
5. Assembly according to any one of claims 3 or 4, characterized in that the trailing edge (31) of the body (26) coincides with a leading edge (16) of the blade (9).
6. Assembly according to any one of claims 1 to 2, characterized in that the body (26) comprises a leading edge (30) from which two wings (38) extend opposite each other, the wings (38) overlapping the intrados and extrados faces (14, 15) of the blade (9).
7. Assembly according to any one of claims 3 to 6, characterized in that the body (26) comprises at least one tube (33) projecting from the leading edge (30), the tube (33) having an inlet orifice (34) at its free end, the tube (33) forming a housing in which the measuring instrument (27) is received.
8. Turbomachine (1) comprising an unshod blower (2) which includes the assembly according to any one of the preceding claims, the foot (10) of the blade (8) being mounted in a recess (11) of a pivot (12) of the blower (2), the measuring device (25) being integral with the blade (8) and / or the pivot (12).