TURBOMACHINE COMPRISING AN UNDUCTED FAN AND A MULTIDIRECTIONAL MEASURING DEVICE

Abstract

Turbomachine (1) with a longitudinal axis (X) comprising: - an unducted fan (2) movable around the axis (X), so as to generate an air flow (F1, F2) flowing around a streamlined body (6) of the turbomachine (1); - at least one multidirectional measuring device (19a-19b) which is integral with the fan (2), the measuring device (19a-19b) comprising a mast and a head which are profiled and placed in the air flow (F1, F2), the head being carried by the mast, the head supporting several measuring instruments distributed on the outer surface of the head and each oriented in a direction, each measuring instrument being configured to measure at least one parameter of the air flow (F1, F2). Figure for the abstract: 1

Description

Title of the invention: TURBOMACHINE COMPRISING AN UNDUCTED FAN AND A MULTIDIRECTIONAL MEASURING DEVICE Technical field of the invention

[0001] The present invention relates to a turbomachine comprising an unducted fan and a multidirectional measuring device. Technical background

[0002] As part 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 modes (in particular "propellant" and "reverser"), with the aim in particular of validating or not certain technical solutions implemented.

[0003] To measure these flow-specific parameters, it is known to implant intrusive measuring devices, more commonly called "combs" because of their shape, in each of the flows studied. A measuring device is conventionally 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 in the vicinity (upstream or downstream) of a ducted fan, it is customary to mount the measuring device on the fixed casing surrounding the fan. However, such a practice cannot be transposed to turbomachines comprising an unducted fan since there is no fixed element in the vicinity of the fan that could be used to support the measuring device.

[0005] For example, a turbomachine known by the English acronym “USF” for “Unducted Single Fan” comprises such an unducted fan.

[0006] Engine manufacturers further note that a static measuring device which is mounted opposite a moving element (for example the fan) generates turbulence which inevitably disrupts the aerodynamic and mechanical behavior of this 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 the parameters (pressure, temperature, etc.) of the boundary layer formed in the immediate vicinity of a moving element (for example the cone or a casing) of the fan to be measured. Indeed, sufficient clearance must be maintained between a static measuring device and a moving element to avoid any collision, the parts being caused to deform when the turbomachine is in operation.

[0008] Finally, engine manufacturers are of the opinion that measurements in several directions would make it possible to define the flow studied more precisely, and in particular the local instabilities.

[0009] The objective of the present invention is therefore to provide a simple, effective and economical solution making it possible to respond to the aforementioned problems. Summary of the invention

[0010] The invention thus proposes a turbomachine with longitudinal axis X comprising: - an unducted fan movable around the X axis, so as to generate an air flow Fl, F2 flowing around a streamlined body of the turbomachine; - at least one multidirectional measuring device which is integral with the blower, the measuring device comprising a mast and a head which are profiled and placed in the air flow Fl, F2, the head being carried by the mast, the head supporting several measuring instruments distributed on the outer surface of the head and each oriented in a direction d, each measuring instrument being configured to measure at least one parameter of the air flow Fl, F2.

[0011] Unlike the prior art, the measuring device is here dynamic and moves together with the blower, which has the following advantages: - the aerodynamic and mechanical behavior of the fan is only disturbed to a lesser extent; - 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 a moving element (for example the cone or a casing) of the fan.

[0012] Furthermore, the measuring device here carries out multidirectional measurements, i.e. measurements in various directions, so as to define the flow studied more precisely (instability, pressure, temperature, etc.).

[0013] The turbomachine according to the invention may comprise one or more of the characteristics, taken in isolation from one another or in combination with one another: - that the directions of the measuring instruments are not parallel to each other; - the head is removably mounted on the mast; - the head is adjustable in rotation relative to the mast; - the head is height adjustable along the mast; - the head includes a recess into which the mast is inserted so that the head can slide along the mast, the head being stopped along the mast by a pin passing simultaneously through an adjustment hole formed in the head and an adjustment orifice formed in the mast; - the head supports at least one row of measuring instruments; - the head supports at least one column of measuring instruments; - the measuring instruments are distributed according to a particular profile such as a cross profile; - the measuring device is configured according to one of the following alternatives: — the measuring device is secured to an inlet cone of the fan and placed upstream of the variable-pitch fan blades; — the measuring device is secured to a fan casing and placed between variable-pitch fan blades and an air inlet intended to supply a gas generator of the turbomachine. Brief description of the figures

[0014] The invention will be better understood and other details, characteristics and advantages of the invention will appear more clearly on reading the following description given by way of non-limiting example and with reference to the appended drawings in which:

[0015] [Fig-1] [Fig.l] is a schematic view in longitudinal half-section of a tur machine according to the invention;

[0016] [Fig.2] [Fig.2] is a detail view of [Fig.l];

[0017] [Fig.3] [Fig.3] is a cross-sectional view of the masts of the devices of measurement of [Fig.l];

[0018] [Fig.4] [Fig.4] is a schematic view of a measuring device according to a first embodiment variant;

[0019] [Fig.5] [Fig.5] is a schematic view of a measuring device according to a second embodiment variant;

[0020] [Fig.6] [Fig.6] is a concrete and perspective view of a measuring device according to a third embodiment variant;

[0021] [Fig.7] [Fig.7] is a sectional view of the measuring device of [Fig.6] along a median sectional plane;

[0022] [Fig.8] [Fig.8] is a view similar to [Fig.l] which illustrates a particular example of the invention. Detailed description of the invention

[0023] In [Fig.l] a turbomachine 1 with longitudinal axis X is schematically represented. The turbomachine 1 comprises an unducted propulsive fan 2 and an unducted fixed rectifier 3. Such a turbomachine 1 is better known by the English acronym USF for “Unducted Single Fan”.

[0024] As illustrated in [Fig.l], the blower 2 is driven in rotation about the axis X by a motor 4 arranged downstream of the blower 2. Such an arrangement of the turbomachine 1 is better known under the designation "tractor" in French or "puller" in English. In such an arrangement, the rectifier 3 is arranged longitudinally downstream of the blower 2.

[0025] The example illustrated in [Fig.l] is in no way limiting, the turbomachine could for example comprise an unducted fan arranged downstream of the engine, or even two unducted counter-rotating fans arranged 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] 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.

[0028] The engine 4 here comprises a gas generator and at least one power turbine (or low-pressure turbine) which is 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 coupled in rotation to each other via a transmission shaft. The gas generator is supplied with air by an air inlet 5 which opens between the fan 2 and the rectifier 3.

[0029] When the turbomachine 1 operates in “propulsor” mode, the fan 2 generates an air flow Fl (also called “direct flow”) which flows generally from upstream to downstream around the external fairings of the streamlined body 6 of the turbomachine 1, so as to propel or move the aircraft forward.

[0030] By convention in the present application, the terms “upstream” and “downstream” are defined relative to the direction of circulation of the air flow F1, the turbomachine 1 then being in “propulsor” mode.

[0031] The turbomachine 1 is here also configured to operate in “reverser” mode, the fan 2 then generates an air flow F2 (also called “reverse flow”) which flows generally from downstream to upstream around the external fairings of the body 6 of the turbomachine 1, so as to brake the aircraft, in particular at the time of its landing.

[0032] In operation (“propulsor” mode or “inverter” mode), a minor part of the air flow F1, F2 is taken by the air inlet 5 to supply the gas generator.

[0033] As illustrated in [Fig.l], the fan 2 comprises a disk 7 carrying an annular row of variable-pitch blades 8, each blade 8 being set around an axis of rotation Y which is specific to it and which is substantially perpendicular to the axis X.

[0034] More precisely, each variable-pitch blade 8 comprises an aerodynamic (or profiled) blade 9 and a root intended to be mounted in a cell of a pivot 10 of the fan 2. The pivot 10 associated with each blade 8 is mounted to move about the Y axis in a housing of the disk 7 via one or more bearings. The disk 7 is driven by the power turbine via a power shaft 11 centered on the X axis and a transmission member 12 coupled in rotation with both the power shaft 11 and the disk 7. The fan 2 also comprises an inlet cone 13 and a profiled casing 14 which covers the disk 7, the inlet cone 13 and the casing 14 being integral with the disk 7.

[0035] As illustrated in [Fig.l], the fan 2 comprises a control system 15 for the pitch of the blades 8, better known by the English acronym PCM for “Pitch Change Mechanism”. The control system 15 may for example comprise an actuator 16 common to all the blades 8 and a mechanism 17 specific to each of the blades 8, this mechanism 17 making it possible to transform the movement initiated by the actuator 16 into a rotational movement of the corresponding blade 8. The movement of the actuator 16 makes it possible to adjust the pitch of all the blades 8 in a synchronized manner, in particular via the different mechanisms 17. Conventionally, in “propulsor” mode, the variable-pitch blades 8 of the fan 2 have a positive pitch angle, and in “reverser” mode, the variable-pitch blades 8 of the fan 2 have a negative pitch angle.

[0036] The fixed rectifier 3 (and in other words not mobile around the axis X) comprises an annular row of guide vanes 18 (or stator vanes), these being able to be variable-pitch or not.

[0037] According to the invention, the turbomachine 1 comprises at least one multidirectional measuring device 19a-19e which is integral with the fan 2.

[0038] More specifically, the measuring device 19a-19e comprises a mast 20 and a head 21 which are profiled and placed in the air flow F1, F2. The head 21 is carried by the mast 20. The head 21 supports several measuring instruments 22 distributed on the outer surface 23 of the head 21 and each oriented in a direction d. Each measuring instrument 22 is configured to measure at least one parameter of the air flow F1, F2.

[0039] The turbomachine 1 can obviously comprise several measuring devices 19a-19e.

[0040] Advantageously, when the turbomachine 1 comprises several measuring devices 19a-19e, the measuring devices 19a-19e are distributed regularly around the axis X, to avoid imbalances.

[0041] Advantageously, when the turbomachine 1 comprises a single measuring device 19a-19e or several measuring devices 19a-19e distributed irregularly, the turbomachine 1 comprises one or more flyweights to balance the fan 2, and in other words to compensate for centrifugal imbalances. The flyweight(s) are generally arranged opposite the measuring device(s) 19a-19e.

[0042] Each measuring instrument 22 supported by the head 21 can obviously be configured to measure several parameters of the air flow F1, F2.

[0043] The measuring instruments 22 are for example pressure sensors (or pressure probes) and / or temperature sensors (or temperature probes).

[0044] Advantageously, the directions d of the measuring instruments 22 are not parallel to each other, so as to extend the range of the measuring device.

[0045] The shape and dimensions of the head 21 may vary. The head 21 is, for example, spherical, polyspherical, triangular, domed, cylindrical, etc.

[0046] The head 21 may have an axis of revolution, the measuring instruments 22 then being able to be distributed along this axis of revolution.

[0047] The measuring instruments 22 can be distributed on the head 21 in a regular or irregular manner.

[0048] The measuring instruments 22 can be distributed in the form of one or more rows 29, and / or in the form of one or more columns 30.

[0049] A row 29 is for example linear, circular, annular, etc. In the same way, a column 30 is for example linear, circular, annular, etc.

[0050] The row(s) 29 of measuring instruments 22 and the column(s) 30 of measuring instruments 22 may intersect.

[0051] The measuring instruments 22 of two adjacent rows 29 can be aligned or offset (for example in a staggered pattern) relative to each other.

[0052] The measuring instruments 22 of two adjacent columns 30 can be aligned or offset (for example in a staggered pattern) relative to each other.

[0053] The pitch between two adjacent measuring instruments 22 of the same row 29 can be regular or irregular.

[0054] The pitch between two adjacent measuring instruments 22 of the same column 30 can be regular or irregular.

[0055] The measuring instruments 22 can be distributed according to a particular profile such as a cross profile or a circular profile.

[0056] The shape and dimensions of the mast 20 may vary. The mast 20 may have, for example, a round section, an oblong section, a U-shaped section, etc.

[0057] The mast 20 can be straight or curved.

[0058] The mast 20 may extend radially or be inclined upstream or downstream.

[0059] The mast 20 and the head 21 may be distinct from each other, the head 21 then being reported and fixed on mast 20.

[0060] The mast 20 and the head 21 may be in one piece (or monobloc).

[0061] The head 21 can be attached (for example welded or screwed) to the mast 20. Advantageously, the head 21 is attached to the mast 20 after the instrumentation (measuring instruments 22) has been installed. The head 21 can be removably mounted on the mast 20.

[0062] The head 21 can be adjustable in rotation relative to the mast 20.

[0063] The head 21 can be adjustable in height along the mast 20.

[0064] A measuring device can be used to understand the measurements of a conventional measuring comb.

[0065] As illustrated in Figures 1 and 2, the turbomachine 1 comprises a first measuring device 19a and a second measuring device 19b.

[0066] The first measuring device 19a is integral with the inlet cone 13 of the fan 2 and is placed upstream of the variable-pitch blades 8 of the fan 2. The mast 20 of the first measuring device 19a is fixed to a sole 24 which is part of the inlet cone 13, the latter being able to be attached and fixed to the inlet cone 13, or else formed in one piece with the inlet cone 13.

[0067] The first measuring device 19a comprises a radial mast 20 at the end of which a spherical head 21 is fixed.

[0068] As illustrated in [Fig. 3], the mast 20 has a U-shaped section and comprises a leading edge 25 from which two wings 26 extend opposite each other. The cavity 27 formed between the two wings 26 allows the passage of the cables of the various measuring instruments 22.

[0069] The head 21 comprises at its lower end a threaded nipple which is screwed into a tapped hole 28 formed at an upper end of the mast 20 at its leading edge 25. The head 21 is thus removably mounted on the mast 20, which makes it possible to mount the same head 21 on different masts 20 which have, for example, different heights.

[0070] The head 21 supports, for example, eight measuring instruments 22 distributed over an upstream portion of the head 21. The measuring instruments 22 are distributed according to a cross profile which is defined by a circular row 29 of four measuring instruments 22 and a circular column 30 of four measuring instruments 22.

[0071] The first measuring device 19a is used here to measure the parameters of the boundary layer of the air flow F1, F2 which is formed in the immediate vicinity of the inlet cone 13.

[0072] The second measuring device 19b is integral with the casing 14 of the fan 2 and is placed between the variable-pitch blades 8 of the fan 2 and the air inlet 5. The mast 20 of the second measuring device 19b is fixed to a sole 31 which is part of the envelope 14, the latter being able to be attached and fixed to the envelope 14, or else formed in one piece with the envelope 14.

[0073] In the same way as the first measuring device 19a, the second measuring device 19b comprises a radial mast 20 at the end of which is fixed a spherical head 21.

[0074] The mast 20 of the second measuring device 19b has the same geometric characteristics as the mast 20 of the first measuring device 19a. Unlike the first measuring device 19a, the mast 20 of the second measuring device 19b has a greater height. The head 21 of the second measuring device 19b is fixed in the same way as the head 21 of the first measuring device 19a.

[0075] The head 21 of the second measuring device 19b for example also supports eight measuring instruments 22 distributed over a central portion of the head 21. The measuring instruments 22 are also distributed according to a cross profile which is defined by a circular row 29 of four measuring instruments 22 and a circular column 30 of four measuring instruments 22.

[0076] The second measuring device 19b is used here to measure the parameters of the air flow F1, F2 at the disturbance node.

[0077] As illustrated in Figures 1 and 2, the turbomachine 1 also comprises a measuring system 32 which is integral with an external fairing 33 of the body 6 and which is placed downstream of the guide vanes 18 of the rectifier 3.

[0078] The measuring system 32 has the same intrinsic characteristics as the measuring device 19a-19d according to the invention. However, unlike the measuring device 19a-19d according to the invention, the measuring system 32 is fixed since it is integral with a fixed element (here an external fairing 33 of the body 6) of the turbomachine 1.

[0079] More precisely, the measuring system 32 comprises a radial mast 20 at the end of which a cylindrical head 21 is fixed.

[0080] The head 21 supports ten annular rows 29 of measuring instruments 22, each row 29 extending around the axis of revolution of the head 21. The rows 29 are staggered, and in other words they are arranged one above the other along the axis of revolution of the head 21. The presence of measuring instruments 22 all around the head 21 (or over 360 degrees) makes it possible to carry out measurements not only when the machine is operating in “propulsor” mode (flow F1) but also when it is operating in “inverter” mode (flow F2), without needing to reorient the measuring system 32. It makes it possible to measure the transient phases between the propellant and the inverter in operation.

[0081] The measuring system 32 is used here to measure the air flow parameters F1, F2 at different heights.

[0082] Such a measuring system 32 can also be used to better calibrate and / or calibrate and / or orient conventional measuring combs.

[0083] Such a measuring system 32 can also be used to interpret the uncertainties of conventional measuring combs.

[0084] According to a first variant embodiment illustrated in [Fig.4], the measuring device 19c comprises a head 21 which is adjustable in rotation relative to the mast 20. For this, the head 21 comprises for example a ball joint housed in a ring which is integral with the mast 20.

[0085] The head 21 is for example adjusted differently depending on the operating modes of the turbomachine 1 (“propellant” or “reverser”), or the operating regimes (takeoff, cruise, etc.).

[0086] According to a second variant embodiment illustrated in [Fig.5], the measuring device 19d comprises a head 21 which is adjustable in height along the mast 20.

[0087] For this, the head 21 comprises a base 34 in which a recess is formed. The mast 20 passes through this recess so that the head 21 can slide along the mast 20. The head 21 is stopped along the mast 20 by a pin 35 simultaneously passing through an adjustment hole formed in the base 34 and an adjustment orifice 36 formed in the mast 20.

[0088] According to a third variant embodiment illustrated in Figures 6 and 7, the measuring device 19e comprises a radial mast 20 at the end of which a spherical head 21 is fixed.

[0089] As illustrated in Figures 6 and 7, the mast 20 has an oblong section and comprises a leading edge 25 and a trailing edge 37 connected to each other by two lateral faces 38. The leading edge 25 is here inclined downstream and the trailing edge 37 here extends radially. The body of the mast 20 is hollow and comprises a radial groove 39, for routing the cables / wires of the various measuring instruments 22. The groove 39 here opens onto one of the lateral faces 38 to facilitate the installation of the measuring instruments 22. The groove 39 can be covered with a cover, to promote aerodynamics. The mast 20 is connected to a base 40 which is fixed to one of the soles 24, 31. The base 40 is here placed in a housing 41 inside the sole 24, 31 and fixed to the sole 24, 31 via four fixing elements (for example screws or bolts) distributed at each of its corners, the mast 20 passing through a radial orifice 42 formed in the sole 24, 31.

[0090] The head 21 supports a measuring instrument 22 at its top and three annular rows 29a-29c of measuring instruments 22, each row 29a-29c extending around the axis of revolution of the head 21. The rows 29a-29c are staggered, and in other words they are arranged one above the other along the axis of revolution of the head 21.

[0091] As illustrated in [Fig.7], the measuring instruments 22 of the first row 29a are oriented at -45 degrees, the measuring instruments 22 of the second row 29b are oriented at 0 degrees, the measuring instruments 22 of the third row 29c are oriented at +45 degrees, and the measuring instrument 22 located at the top of the head 21 is oriented at +90 degrees.

[0092] According to the particular example illustrated in [Fig.8], the turbomachine 1 comprises the first and second measuring devices 19a, 19b arranged at a determined angular position. To balance the fan 2, and in other words to compensate for centrifugal imbalances, the turbomachine 1 comprises a first flyweight 43 which is diametrically opposite the first measuring device 19a and a second flyweight 44 which is diametrically opposite the second measuring device 19b.

Claims

Claims

1. Turbomachine (1) with longitudinal axis (X) comprising: - an unducted fan (2) movable around the axis (X), so as to generate an air flow (Fl, F2) flowing around a streamlined body (6) of the turbomachine (1); - at least one multidirectional measuring device (19a-19e) which is integral with the blower (2), the measuring device (19a-19e) comprising a mast (20) and a head (21) which are profiled and placed in the air flow (Fl, F2), the head (21) being carried by the mast (20), the head (21) supporting several measuring instruments (22) distributed on the outer surface (23) of the head (21) and each oriented in a direction (d), each measuring instrument (22) being configured to measure at least one parameter of the air flow (Fl, F2).

2. Turbomachine (1) according to claim 1, characterized in that the directions (d) of the measuring instruments (22) are not parallel to each other.

3. Turbomachine (1) according to one of the preceding claims, characterized in that the head (21) is removably mounted on the mast (20).

4. Turbomachine (1) according to one of the preceding claims, characterized in that the head (21) is adjustable in rotation relative to the mast (20).

5. Turbomachine (1) according to one of the preceding claims, characterized in that the head (21) is adjustable in height along the mast (20).

6. Turbomachine (1) according to the preceding claim, characterized in that the head (21) comprises a recess into which the mast (20) is introduced so that the head (21) can slide along the mast (20), the head (21) being stopped along the mast (20) by a pin (35) simultaneously passing through an adjustment hole formed in the head (21) and an adjustment orifice (36) formed in the mast (20).

7. Turbomachine (1) according to one of the preceding claims, characterized in that the head (21) supports at least one row (29, 29a-29c) of measuring instruments (22).

8. Turbomachine (1) according to one of the preceding claims, characterized in that the head (21) supports at least one column (30) of measuring instruments (22).

9. Turbomachine (1) according to one of the preceding claims, characterized in that the measuring instruments (22) are distributed according to a particular profile such as a cross profile.

10. Turbomachine (1) according to one of the preceding claims, characterized in that the measuring device (19a-19e) is configured according to one of the following alternatives: - the measuring device (19a) is integral with an inlet cone (13) of the fan (2) and placed upstream of the variable-pitch blades (8) of the fan (2); - the measuring device (19b) is integral with a casing (14) of the fan (2) and placed between variable-pitch blades (8) of the fan (2) and an air inlet (5) intended to supply a gas generator of the turbomachine (1).

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