TURBOMACHINE COMPRISING AN UNFAIRED BLOWER AND A MULTIDIRECTIONAL MEASURING DEVICE

Abstract

A turbomachine (1) with a longitudinal axis (X) comprising: - an unfaired fan (2) movable about the axis (X), so as to generate an airflow (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 positioned in the airflow (F1, F2), the head being supported by the mast, the head supporting several measuring instruments distributed over 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 airflow (F1, F2). Figure for the abstract: 1

Description

Title of the invention: TURBOMACHINE COMPRISING AN UNFACED BLOWER AND A MULTIDIRECTIONAL MEASURING DEVICE Technical field of the invention

[0001] The present invention relates to a turbomachine comprising an unshrouded blower and a multidirectional measuring device. 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 modes (in particular "propeller" and "reversing"), 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 airflow parameters in the vicinity (upstream or downstream) 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] 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 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 a moving element (for example, the cone or a casing) of the fan. Indeed, sufficient clearance must be maintained between a static measuring device and a moving element to avoid any collision, the parts being prone to deformation when the turbomachine is in operation.

[0008] Engine manufacturers are finally of the opinion that measurements along several directions would allow for a more precise definition of the flow studied, and in particular the local instabilities.

[0009] 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

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

[0011] Unlike the prior art, the measuring device here is dynamic and moves in conjunction with the blower, which offers the following advantages: - the aerodynamic and mechanical behavior of the blower 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 shell) of the blower.

[0012] In addition, the measuring device here performs multidirectional measurements, that is to say measurements along various directions, in order to define more precisely the flow studied (instability, pressure, temperature, etc.).

[0013] The turbomachine according to the invention may comprise one or more of the following features, taken individually or in combination with each other: - that the directions of the measuring instruments are not parallel to each other; - the head is mounted removably 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 attached to an inlet cone of the blower and placed upstream of the variable pitch blades of the blower; — the measuring device is attached to a casing of the blower and placed between variable pitch blades of the blower 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 bomachine according to the invention;

[0016] [Fig.2] [Fig.2] is a detailed view of [Fig.1];

[0017] [Fig.3] [Fig.3] is a cross-sectional view of the masts of the devices measurement of the [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 cross-sectional view of the measuring device of [Fig.6] along a median cutting plane;

[0022] [Fig.8] [Fig.8] is a view similar to [Fig.1] which illustrates a particular example of the invention. 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 a fixed unducted 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 blower 2 is driven in rotation about the X-axis by a motor 4 located downstream of the blower 2. Such an arrangement of the turbine 1 is more commonly known as a "tractor" in French or a "puller" in English. In such an arrangement, the straightener 3 is located 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] By convention in this 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) 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.

[0029] When the turbomachine 1 operates in "propulsion" mode, the fan 2 generates an airflow Fl (also called "direct flow") which flows globally from upstream to downstream around the outer fairings of the streamlined body 6 of the turbomachine 1, so as to propel or move the aircraft forward.

[0030] By convention in this application, the terms "upstream" and "downstream" are defined with respect to the direction of airflow Fl, the turbomachine 1 then being in "propeller" mode.

[0031] The turbomachine 1 is also configured here to operate in "reversing" mode, the fan 2 then generates an airflow F2 (also called "reverse flow") which flows globally from downstream to upstream around the outer fairings of the body 6 of the turbomachine 1, so as to slow the aircraft, particularly at the time of its landing.

[0032] In operation (in "propeller" mode or "reversing" mode), a minor part of the airflow Fl, F2 is taken from the air inlet 5 to supply the gas generator.

[0033] 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.

[0034] More specifically, each variable-pitch blade 8 comprises an aerodynamic (or profiled) blade 9 and a foot for mounting in a recess of a pivot 10 of the fan 2. The pivot 10 associated with each blade 8 is movably mounted 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 rotationally coupled to both the power shaft 11 and the disk 7. The fan 2 also comprises an inlet cone 13 and a profiled casing 14 that covers the disk 7, the inlet cone 13 and the casing 14 being integral with the disk 7.

[0035] As illustrated in [Fig. 1], the fan 2 includes 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, include an actuator 16 common to all the blades 8 and a mechanism 17 specific to each of the blades 8, this mechanism 17 transforming the movement initiated by the actuator 16 into a rotational movement of the corresponding blade 8. The movement of the actuator 16 allows for the synchronized adjustment of the pitch of all the blades 8 via, in particular, the various mechanisms 17. Typically, in "propeller" mode, the variable-pitch blades 8 of the fan 2 have a positive pitch angle, and in "reversing" 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 X axis) 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 blower 2.

[0038] More specifically, the measuring device 19a-19e comprises a mast 20 and a head 21 which are profiled and placed in the airflow Fl, F2. The head 21 is supported 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 along a direction d. Each measuring instrument 22 is configured to measure at least one parameter of the airflow Fl, F2.

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

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

[0041] Advantageously, when the turbomachine 1 comprises a single measuring device 19a-19e or several irregularly distributed measuring devices 19a-19e, the turbomachine 1 includes one or more counterweights to balance the fan 2, and in other words, to compensate for centrifugal imbalances. The counterweight(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 airflow Fl, 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 can 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 can then 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 arranged 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 or rows 29 of measuring instruments 22 and the column or columns 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) with respect to each other.

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

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

[0054] The pitch between two adjacent measuring instruments 22 in 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 can vary. The mast 20 can, for example, have a round section, an oblong section, a U-shaped section, etc.

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

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

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

[0060] The mast 20 and the head 21 can 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 adjusted in rotation relative to the mast 20.

[0063] The head 21 can be adjusted 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 attached to the inlet cone 13 of the blower 2 and is placed upstream of the variable pitch blades 8 of the blower 2. The mast 20 of the first measuring device 19a is fixed to a base 24 which is part of the inlet cone 13, the latter being able to be added and fixed to the inlet cone 13, or formed as a single piece with the inlet cone 13.

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

[0068] As illustrated in [Fig. 3], the mast 20 has a U-shaped cross-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 cables for the various measuring instruments 22.

[0069] The head 21 includes at its lower end a threaded stud which is screwed into a tapped hole 28 formed at an upper end of the mast 20 at the level of its leading edge 25. The head 21 is thus mounted removably on the mast 20, which allows the same head 21 to be mounted 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 airflow boundary layer Fl, 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 blower 2 and is positioned between the variable-pitch blades 8 of the blower 2 and the air inlet 5. The mast 20 of the second measuring device 19b is fixed to a base 31 which forms part of envelope 14, this one being able to be attached and fixed to envelope 14, or formed in one piece with 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 also supports, for example, 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 airflow parameters Fl, F2 at the level of the disturbance node.

[0077] As illustrated in Figures 1 and 2, the turbomachine 1 also includes 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 outer fairing 33 of the body 6) of the turbomachine 1.

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

[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 perform measurements not only when the machine is operating in "propeller" mode (flux Fl) but also when it is operating in "reversing" mode (flux F2), without needing to reorient the measuring system 32. It makes it possible to measure the transient phases between propeller and reversing during operation.

[0081] The measuring system 32 is used here to measure the airflow parameters Fl, F2 over different heights.

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

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

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

[0085] The head 21 is for example adjusted differently according to the operating modes of the turbomachine 1 (“propeller” or “reversing”), or the operating regimes (takeoff, cruise, etc.).

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

[0087] For this purpose, 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 held in place along the mast 20 by a pin 35 passing simultaneously through an adjustment hole formed in the base 34 and an adjustment orifice 36 formed in the mast 20.

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

[0089] As illustrated in Figures 6 and 7, the mast 20 has an oblong cross-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 inclined downstream, and the trailing edge 37 extends radially. The body of the mast 20 is hollow and includes a radial groove 39 for routing the cables / wires of the various measuring instruments 22. The groove 39 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 improve aerodynamics. The mast 20 is connected to a base 40 which is fixed to one of the flanges 24, 31. The base 40 is here placed in a housing 41 inside the flange 24, 31 and fixed to the flange 24, 31 via four fixing elements (for example screws or bolts) distributed at each of its corners, the mast 20 passing through a radial hole 42 formed in the flange 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 stepped, 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 blower 2, and in other words to compensate for centrifugal imbalances, the turbomachine 1 comprises a first counterweight 43 which is diametrically opposite the first measuring device 19a and a second counterweight 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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