Aircraft turbomachine blade comprising an electromagnet and associated method

Abstract

A blade (1) for an aircraft propulsion turbomachine, the blade (1) extending longitudinally along a blade axis (XA), the blade (1) comprising at least one foot portion (11) and at least one tip portion (12) connected by at least one main electromagnet (5) configured to be electrically powered, the main electromagnet (5) being configured, when activated, to generate a holding force (F) between the tip portion (12) and the foot portion (11) during operation of the turbomachine and configured, when deactivated, to cancel said holding force (F). Abstract figure: Figure 2

Description

Title of the invention: Aircraft turbomachine blade comprising an electromagnet and associated method technical field

[0001] The present invention relates to the field of blades for a turbomachine for the propulsion of an aircraft.

[0002] Climate change is a major concern for many legislative and regulatory bodies worldwide. Indeed, various restrictions on carbon emissions have been, are being, or will be adopted by various states. In particular, an ambitious standard applies both to new types of aircraft and to those already in service, requiring the implementation of technological solutions to bring them into compliance with current regulations. Civil aviation has been actively contributing to the fight against climate change for several years now.

[0003] Technological research efforts have already led to very significant improvements in the environmental performance of aircraft. The Applicant takes into account the factors impacting all phases of design and development in order to obtain aeronautical components and products that are less energy-intensive, more environmentally friendly, and whose integration and use in civil aviation have moderate environmental consequences, with the aim of improving the energy efficiency of aircraft.

[0004] Consequently, the Applicant is constantly working to reduce its negative climate impact by using methods and operating virtuous development and manufacturing processes that minimize greenhouse gas emissions to the minimum possible in order to reduce the environmental footprint of its activity.

[0005] This sustained research and development work focuses on new generations of aircraft engines, the weight reduction of aircraft, in particular through the materials used and lighter on-board equipment, the development of the use of electrical technologies to provide propulsion, and, as essential complements to technological progress, aviation biofuels.

[0006] An aircraft is traditionally equipped with one or more ducted turbomachines, such as a turbojet engine. A ducted turbomachine thus comprises an external casing inside which an airflow is accelerated by the rotation of one or more wheels equipped with blades. Such an external casing guides the accelerated airflow for the propulsion of the aircraft and also ensures the retention of a blade in case of loss due to malfunction. Thus, the lost blade remains trapped in the outer casing and cannot damage the aircraft structure.

[0007] In order to reduce the mass of a turbomachine, it has been proposed to equip an aircraft with unfaired turbomachines called turboprops. One disadvantage of a turboprop is that in the event of the loss of a blade, there is no external casing to ensure its retention, and there is therefore a risk of damage to the aircraft structure.

[0008] An immediate solution to eliminate this drawback would be to cover the aircraft's outer surface with a layer of armor plating to protect its structure in the event of a blade loss. Such a solution runs counter to the objectives of reducing an aircraft's mass to lessen its environmental impact.

[0009] The invention thus aims to eliminate at least some of these drawbacks. PRESENTATION OF THE INVENTION

[0010] The invention relates to a blade for an aircraft propulsion turbomachine, the blade extending longitudinally along a blade axis, the blade comprising at least a foot portion and at least a head portion connected by at least one main electromagnet configured to be electrically powered, the main electromagnet being configured, when activated, to generate a retention force between the head portion and the foot portion during the use of the turbomachine and configured, when deactivated, to cancel said retention force.

[0011] Thanks to the invention, a portion of the blade tip can be detached in a controlled manner at a specific location (at the electromagnet) and at a specific time (the deactivation time). This allows the aircraft structure to be protected by deactivating the electromagnet of a blade with a damaged tip section so that it detaches at a distance from the aircraft structure. The tip section to be detached is predetermined, which improves aerodynamic performance.

[0012] Such an invention is also of great interest for testing the tearing of a material bond between a head and a foot portion. The electromagnet can be used instead of explosives to force blade loss. Blade loss is thus controlled and safe.

[0013] According to one aspect, the main electromagnet comprises a cathode connected to the head part and an anode connected to the foot part, the anode being configured to be electrically powered to generate the retention force.

[0014] According to one aspect, the anode cooperates with the cathode via a plane-to-plane connection. Such a connection is simple to achieve.

[0015] According to one aspect, the anode cooperates with the cathode via a sliding connection, in particular, by a dovetail joint. Such a sliding joint allows This is an advantageous way to guide the loss of a blade tip section, thus limiting the risk of damage to an aircraft structure. Such a connection also helps to keep the debris away from neighboring blades, which is advantageous compared to a blade loss according to the prior art, which can damage one or two adjacent blades.

[0016] According to one aspect, the main electromagnet extends along a main electromagnet axis that is transverse to the blade axis. Thus, a loss of a portion of the head aims to limit its radial length.

[0017] According to one aspect, the main electromagnet extends along a main electromagnet axis that is inclined relative to the blade axis at an angle of inclination between 10° and 75°. Generally, the angle of inclination is defined to form a positive slope downstream to reduce damage to neighboring blades. This improves guidance in the event of a loss of a head portion.

[0018] According to one aspect, several parts or sub-parts of the blade are detached successively, for example, with a regular time interval.

[0019] According to one aspect, the blade includes at least one sheath in which is mounted at least one electrical cable for supplying the main electromagnet, the sheath being housed in the foot part.

[0020] According to one aspect, the head portion comprises at least a first sub-part and a second sub-part connected by at least one auxiliary electromagnet configured to be electrically powered. When activated, the auxiliary electromagnet is configured to generate an auxiliary retaining force between the first and second sub-parts during turbomachine operation, and when deactivated, it is configured to cancel this auxiliary retaining force. This allows only one sub-part of a blade to be detached, which is advantageous for removing only a damaged sub-part or for balancing a rotor wheel during its rotation.

[0021] According to one aspect, the foot portion and the head portion are independent. Thus, they can be separated without breaking the material bond. A new head portion can be conveniently installed.

[0022] According to one aspect, the foot portion and the head portion are joined securely by a material bond. This allows for controlled testing of a tear in the material bond.

[0023] Also presented is a turbomachine comprising at least one rotor wheel with a plurality of blades as previously described and at least one computer configured to control each main electromagnet so as to allow the loss of a portion of the blade tip. Blade loss can thus be actively controlled to protect the aircraft structure.

[0024] According to one aspect, each blade is configured to move circumferentially, and the computer is configured to deactivate a main electromagnet of a blade when said blade is positioned within a predetermined angular detachment range. Preferably, each turbomachine is associated with an angular detachment range based on its mounting location relative to the aircraft structure.

[0025] According to one aspect, the computer is configured to deactivate a selection of main electromagnets in the event of detection of an imbalance.

[0026] In one aspect, the turbomachine is a turboprop. This allows for control of blade loss in the absence of an external casing.

[0027] In another respect, the turbomachine is a turbojet. This is particularly advantageous for testing the rupture of a material bond.

[0028] Also presented is an aircraft comprising at least one turbomachine as previously presented.

[0029] A method for controlling a blade as described above is also presented, the main electromagnet being activated during the rotation of the turbomachine to ensure a retention force between the tip and the foot section. The method includes a step of deactivating the main electromagnet during the rotation of the turbomachine so as to cancel said retention force. This allows the tip section to be released in a controlled and safe manner.

[0030] According to one aspect, the method includes a step of deactivating the main electromagnet during the rotation of the turbomachine so as to cancel the retention force and thus allow the head portion to be detached. The detachment is controlled, and a new head portion can be mounted in place of the detached one.

[0031] According to one aspect, the method includes a step of inactivating the main electromagnet during the rotation of the turbomachine so as to cancel the retention force and thus allow the material bond between the foot and head parts to break. This makes it possible to test material tearing in a controlled and safe manner compared to conventional use of explosives.

[0032] The invention also relates to a computer program type product, comprising at least one sequence of instructions stored and readable by a processor and which, once read by this processor, causes the execution of the steps of the process as previously presented.

[0033] The invention further relates to a computer-readable medium comprising the computer program-type product as previously described. PRESENTATION OF THE FIGURES

[0034] The invention will be better understood upon reading the following description, given by way of example, and referring to the following figures, given by way of non-limiting examples, in which identical references are given to similar objects.

[0035] Fig. 1 is a schematic representation of an aircraft equipped with propulsion turbomachinery.

[0036] Fig. 2 is a schematic representation of a turbomachine blade according to a first embodiment.

[0037] The [Fig.3] is a schematic representation of the blade of the [Fig.2] following the detachment of a part of the head.

[0038] The [Fig.4] is a schematic representation of a variant of the dawn of the [Fig.2].

[0039] Figure 5 is a schematic representation of a plane-to-plane connection between a cathode and an anode of an electromagnet.

[0040] Fig. 6 is a schematic representation of a dovetail sliding joint between a cathode and an anode of an electromagnet.

[0041] Fig. 7 is a schematic representation of a blade whose head part has detachable sub-parts.

[0042] The [Fig.8] is a schematic representation of a detachment of a sub-part.

[0043] Figure 9 is a schematic representation of a detachment from another sub-section. part.

[0044] The [Fig. 10] is a schematic representation of a predetermined angular range for the detachment of a part of the head of a blade.

[0045] Fig. 11 is a schematic representation of a step in the detachment of several blades.

[0046] Fig. 12 is a schematic representation of a turbomachine blade according to a second embodiment, the main electromagnet being activated.

[0047] The [Fig.13] is a schematic representation of the blade of the [Fig.12] following the inactivation of the main electromagnet.

[0048] The [Fig.14] is a schematic representation of the blade of the [Fig.13] following the tearing of the blade.

[0049] It should be noted that the figures set out the invention in detail to implement the invention, said figures being of course able to serve to better define the invention where appropriate. DETAILED DESCRIPTION OF THE INVENTION

[0050] With reference to [Fig. 1], an aircraft A is shown comprising several turbomachines T for its propulsion. In this example, each turbomachine T is a turboprop, that is to say, a turbomachine without a casing. external. However, as will be shown later, the invention also applies to a ducted T turbomachine which includes an external casing.

[0051] With further reference to [Fig. 1], the turbomachine 1 comprises one or more rotor wheels RI comprising a plurality of blades 1 to provide propulsion. During flight, the turbomachine 1 is liable to collide with foreign bodies such as birds, which may weaken one or more blades 1 of one or more rotor wheels RI, potentially leading to the uncontrolled loss of a blade.

[0052] With reference to [Fig. 2], a blade 1 is shown extending longitudinally along a blade axis XA. When the blade 1 is mounted on a rotor wheel RI, the blade 1 extends radially with respect to the axis of rotation of the rotor wheel RL

[0053] The blade 1 comprises at least one foot portion 11 and at least one head portion 12 connected by at least one main electromagnet 5. The foot portion 11 preferably corresponds to the portion intended to be mounted in a hub of the rotor wheel RL. Preferably, the foot portion 11 and the head portion 12 are made of a composite material in order to have a reduced mass. The material particularly comprises reinforcing fibers and a composite matrix.

[0054] In this example, the foot part 11 and the head part 12 are independent. They can therefore be manipulated independently and assembled together by means of the main electromagnet 5.

[0055] The main electromagnet 5 is configured to be electrically powered. The main electromagnet 5 is configured, when activated, to generate a retention force F between the head part 12 and the foot part 11 during the use of the turbomachine T and configured, when deactivated, to cancel said retention force F.

[0056] In this example, the main electromagnet 5 is integrated into the composite matrix.

[0057] Whereas the foot part 11 of the blade 1 is rigidly connected to the hub of The rotor wheel RI is mechanically linked to the blade tip 12, which is connected to the foot tip 11 by a magnetic link that provides the holding force F. Thus, as long as the electromagnet 5 is electrically powered (activated), the tip 12 is held in place as illustrated in [Fig. 2]. Conversely, when the electromagnet 5 is no longer electrically powered (deactivated), the tip 12 detaches from the foot tip 11 as illustrated in [Fig. 3]. This allows the tip 12 to be lost in a controlled manner, as will be described in detail later.

[0058] With reference to [Fig. 2], the main electromagnet 5 extends along a main electromagnet axis XE which is transverse to the blade axis XA. Under the effect of centrifugal force, the head portion 12 moves radially outwards. A This orientation of the main electromagnet axis XE allows a large blade surface to be detached, in particular, greater than 75%.

[0059] According to one embodiment, with reference to [Fig. 4], the main electromagnet 5 extends along a main electromagnet axis XE which is inclined relative to the blade axis XA at ​​an angle of inclination 0 between 10° and 75°. Such an orientation of the main electromagnet axis XE makes it possible to conveniently guide the head portion 12 during its detachment, thus allowing for better control of its evacuation direction.

[0060] With reference to [Fig. 2], the main electromagnet 5 comprises a cathode 52 connected to the head portion 12 and an anode 51 connected to the foot portion 11. The anode 51 is configured to be electrically powered to generate the holding force F by magnetic attraction. The cathode 52 comprises a magnetized surface configured to be attracted by the anode 51. Such a structure for an electromagnet is known per se and will not be described in further detail.

[0061] Preferably, an interface surface is defined between the anode 51 and the cathode 52. The latter is at least equal to 50% of the blade profile section, preferably at least 51%.

[0062] The anode 51 and the cathode 52 cooperate magnetically when the anode 51 is energized, but they can also cooperate mechanically. According to one aspect, with reference to [Fig. 5], the anode 51 cooperates with the cathode 52 via a plane-to-plane connection, which simplifies the fabrication of the main electromagnet 5.

[0063] According to another aspect, with reference to [Fig. 6], the anode 51 cooperates with the cathode 52 by means of a sliding joint, in particular, by a dovetail joint. This advantageously guides the detachment of the head portion 12 under the effect of centrifugal force. Such a joint is particularly suitable when the axis of the main electromagnet XE is inclined relative to the axis of the blade XA as illustrated in [Fig. 4].

[0064] With further reference to [Fig. 2], the blade 1 comprises at least one sheath 2 in which at least one electrical cable 3 is mounted for supplying power to the main electromagnet 5. The sheath 2 is housed in the foot portion 11. This advantageously allows for power supply via the hub of the rotor wheel RL

[0065] Preferably, the turbomachine T includes at least one computer 4 configured to control the main electromagnets 5 of each blade 1 so as to allow a loss of a part of the head 12 of a blade 1. The computer 4 is preferably connected to each electrical cable 3 in order to achieve selective deactivation.

[0066] According to one aspect, with reference to [Fig.7], the head part 12 comprises at least a first subpart 12a and a second subpart 12b connected by at least one auxiliary electromagnet 5a configured to be electrically powered. The auxiliary electromagnet 5a is configured, when activated, to generate an auxiliary retention force Fa between the first subpart 12a and the second subpart 12b when using the turbomachine T and configured, when deactivated, to cancel said auxiliary retention force FA.

[0067] In this example, with reference to [Fig. 7], the head portion 12 comprises four sub-parts 12a, 12b, 12c, 12d and three auxiliary electromagnets 5a, 5b, 5c. It is understood that the number of sub-parts 12a, 12b, 12c, 12d and auxiliary electromagnets 5a, 5b, 5c could be different. Such a partitioning of the head portion 12 allows for calibrating the mass of the head portion 12 to be detached. This can be particularly advantageous for correcting an imbalance in the rotor wheel RI.

[0068] Preferably, each auxiliary electromagnet 5a, 5b, 5c has a structure analogous to a main electromagnet 5. Each auxiliary electromagnet 5a, 5b, 5c thus comprises a cathode 52a, 52b, 52c and an anode 51a, 51b, 51c configured to be powered. In this example, each anode 51a, 51b, 51c is connected by at least one electrical cable 3 for powering its auxiliary electromagnet 5a, 5b, 5c.

[0069] In this example, each auxiliary electromagnet 5a, 5b, 5c is integrated into the composite matrix.

[0070] The electrical cables 3 are mounted in one or more sheaths 2 housed in the blade 1. With reference to [Fig.7], the electrical cables 3 are connected to the computer 4. In the case of a head part 12 comprising several sub-parts 12a-12d, the computer 4 allows for selective deactivation so as to detach one or more desired sub-parts 12a-12d.

[0071] According to one aspect, the activation current of the main electromagnet 5 or auxiliary electromagnet 5a-5c is controlled, in particular, progressively reduced to detach a portion of the blade. This is advantageous for an inclined electromagnet, which can thus slide while controlling its speed of movement.

[0072] With reference to [Fig.8], only the auxiliary electromagnet 5c is deactivated to detach the sub-part 12d from the head part 12. Such a detachment may be relevant to correct an imbalance during a flight of aircraft A.

[0073] With reference to [Fig.9], the auxiliary electromagnet 5a is deactivated to detach the sub-parts 12b, 12c, 12d from the head part 12. Such a detachment may be relevant to correct an imbalance during a flight of aircraft A. The auxiliary electromagnets 5b, 5c are automatically deactivated when their electrical cables 3 are broken.

[0074] With reference to [Fig. 10], a rotor wheel RI comprising a plurality of blades 1 is schematically represented. Each blade 1 comprises at least one main electromagnet 5. By convention, in Figures 10 and 11, an electromagnet principal 5 is represented by a black disk when activated (with retention force F) and by a white disk when deactivated (without retention force F).

[0075] Each blade 1 is configured to move circumferentially through an angular range of 360°, between -180° and +180°. By convention, the upper angular position corresponds to 0° (12 o'clock) while the lower angular position corresponds to 180° (6 o'clock). The example is given for an aircraft structure positioned at -90° (9 o'clock).

[0076] According to one aspect, the computer 4 is configured to deactivate a main electromagnet 5 of a blade 1 when said blade 1 is positioned within a predetermined angular detachment range PL. In this example, each blade 1 is referenced and its angular position is known at any given time, in particular, by an angular sensor. In this example, with reference to [Fig. 10], the rotor wheel RI rotates clockwise. The predetermined angular detachment range PI is determined here so as to detach the blade 1 in a manner opposite to the structure of the aircraft A and, preferably, upwards so as to reduce the speed of the blade 1 due to friction when it falls back to the ground. Preferably, the predetermined angular detachment range PI is between a first angle al and a second angle a2. Preferably, the first angle al is less than 0°. Preferably, the second angle a2 is greater than 0°.This helps reduce the risk of damage to neighboring blades.

[0077] For the sake of brevity, the term "blade detachment 1" refers to the detachment of a part of the head 12 of a blade 1 by inactivation of its main electromagnet 5 or of at least a sub-part of a head part by deactivation of its auxiliary electromagnet.

[0078] When a head part 12 of a blade 1 is to be detached, the computer 4 deactivates the main electromagnet 5 when its angular position is within the predetermined detachment angular range PI so as to preserve the integrity of the structure of the aircraft A. The detachment of the head part 12 of the blade 1 is controlled.

[0079] Preferably, to account for the information processing time between a deactivation command from the control unit 4 and an actual detachment, a command angular range PO is defined, which is located before the predetermined detachment angular range PI within which the control unit 4 can issue a deactivation command. The angular ranges PO and PI may overlap, be distinct, or be adjacent.

[0080] According to one aspect, the computer 4 is configured to deactivate a selection of main electromagnets 5 or auxiliary electromagnets 5a-5c in the event of detection of an imbalance on the rotor wheel RI or following the reception of an electrical signal transmitted to the computer 4. By way of example, the deformation of a blade 1 could be measured, in particular with a plurality of strain gauges, and the computer 4 could deactivate a selection of main electromagnets 5 or auxiliary electromagnets 5a-5c if excessive deformation is detected. The deformation of a blade 1 could be measured in real time.

[0081] Preferably, for the selected blades, each head portion 12 of a blade 1 is detached when its angular position is within the predetermined detachment angular range PI. By way of example, with reference to [Fig. 1 1], a rotor wheel RI is shown with ten blades 1, which are referenced 1-1 to 1-10. Blade 1-1 has a defect DEF (for example, the beginning of a break) and blade 1-1 must be detached, which will result in an imbalance. In order to correct this imbalance, the computer 4 detaches blades 1-4 and 1-8 as illustrated in [Fig. 1 1] to obtain a more balanced rotation of the rotor wheel RL. Preferably, blades 1-1, 1-4, and 1-8 are detached synchronously.

[0082] Thus, the calculator 4 is configured, in certain configurations, to detach a selection of blades instead of a single blade in order to correct the imbalance.

[0083] With reference to Figures 12 to 14, a blade 1 is shown in another embodiment. In this embodiment, the foot portion 11 and the tip portion 12 are rigidly connected, in particular by a material bond. Such a blade 1 is advantageous in the field of experimentation and testing for blade loss due to material tearing.

[0084] As illustrated in [Fig. 12], the blade 1 comprises a body 10 which has a cavity 13 in which the main electromagnet 5 is integrated. In particular, the main electromagnet 5 has a cathode 52, mounted in the cavity 13 and connected to the tip portion 12, and an anode 51, partially mounted in the cavity 13 and connected to the foot portion 11. Preferably, the cathode 52 has a shoulder 520 configured to ensure a retention force on the tip portion 12 when a retention force F is exerted between the cathode 52 and the anode 51. The cathode 52 reinforces the blade 1 but also serves as an ejection mass. This allows for practical variation of the experimental protocol.

[0085] According to one aspect, the anodes 51 of the blades 1 can be connected together and form a common anode.

[0086] When mounting the blade 1 in a rotor wheel RI, the hub of the rotor wheel RI is connected to the foot part 11 and to the anode 51. When the electromagnet 5 is activated ([Fig.12]), the head part 12 of the blade 1 is retained, on the one hand, by its material connection with the foot part 11 according to a first zone Z1 and, on the other hand, indirectly by the cathode 52 retained by the anode 51 according to a second zone Z2.

[0087] To test for a material tear at the foot part 11, the computer 4 deactivates the electromagnet 5 as illustrated in [Fig. 13], which cancels the retention force F. The cathode 52 separates from the anode 51 under the effect of the centrifugal force and the head part 12 of the blade 1 is retained only by its material bond with the foot part 11 along the first zone Zl.

[0088] As rotation progresses, the material bond is insufficient to withstand the centrifugal force, which tears the material bond at the interface along a tear zone ZR between the foot portion 11 and the tip portion 12, as illustrated in [Fig. 14]. The tear zone ZR can then be analyzed. This allows for a rigorous and controlled characterization of the blade loss phenomenon. The loss of a blade 11 can be controlled. This method advantageously offers an alternative to the use of explosives, thus improving the safety of the operators in charge of the tests.

Claims

Demands

1. Blade (1) for a turbomachine (T) propulsion of an aircraft (A), the blade (1) extending longitudinally along a blade axis (XA), the blade (1) comprising at least one foot portion (11) and at least one head portion (12) connected by at least one primary electromagnet (5) configured to be electrically powered, the primary electromagnet (5) being configured, when activated, to generate a retention force (F) between the head portion (12) and the foot portion (11) during the use of the turbomachine (T) and configured, when deactivated, to cancel said retention force (F).

2. Blade (1) according to claim 1, wherein the main electromagnet (5) comprises a cathode (52) connected to the head portion (12) and an anode (51) connected to the foot portion (11), the anode (51) being configured to be electrically powered to generate the retention force (F).

3. Blade (1) according to any one of claims 1 to 2, wherein the anode (51) cooperates with the cathode (52) according to a plane-to-plane connection.

4. Blade (1) according to any one of claims 1 to 2, wherein the anode (51) cooperates with the cathode (52) according to a sliding connection, in particular, by a dovetail cooperation.

5. Blade (1) according to any one of claims 1 to 4, wherein the main electromagnet (5) extends along a main electromagnet axis (XE) which is transverse to the blade axis (XA).

6. Blade (1) according to any one of claims 1 to 4, wherein the main electromagnet (5) extends along a main electromagnet axis (XE) which is inclined with respect to the blade axis (XA) by an angle of inclination (0) between 10° and 75°.

7. Blade (1) according to any one of claims 1 to 6, wherein the head part (12) comprises at least a first subpart (12a) and a second subpart (12b) connected by at least one auxiliary electromagnet (5a) configured to be electrically powered, the auxiliary electromagnet (5a) being configured, when activated, to generate an auxiliary retention force (Fa) between the first subpart (12a) and the second subpart (12b) during the use of the turbomachine (T) and configured, when deactivated, to cancel said auxiliary retention force (Fa).

8. Blade (1) according to any one of claims 1 to 7, wherein the foot part (11) and the head part (12) are independent.

9. Blade (1) according to any one of claims 1 to 7, wherein the foot part (11) and the head part (12) are joined together by a material bond.

10. Turbomachine (T) comprising at least one rotor wheel (RI) comprising a plurality of blades (1) according to any one of claims 1 to 9 and at least one computer (4) configured to drive each main electromagnet (5) so as to permit a loss of a head portion (12) of a blade (1).

11. Turbomachine (T) according to claim 10, wherein, each blade (1) is configured to move circumferentially, the computer (4) is configured to deactivate a main electromagnet (5) of a blade (1) when said blade (1) is positioned within a predetermined angular detachment range (PI).

12. Turbomachine (T) according to any one of claims 10 to 11, wherein the turbomachine (T) is a turboprop.

13. Method of controlling a blade (1) according to any one of claims 1 to 9, main electromagnet T (5) being activated during the rotation of the turbomachine (T) to ensure a retention force (F) between the head part (12) and the foot part (11), the method comprising a step of: • Deactivating main electromagnet T (5) during the rotation of the turbomachine (T) so as to cancel said retention force (F).

14. Method of controlling a blade according to claims 8 and 13 taken in combination, the method comprising a step of: • Deactivating the main electromagnet (5) during the rotation of the turbomachine (T) so as to cancel said retention force (F) so as to allow the loss of the head part (12).

15. A method for controlling a blade (1) according to claims 9 and 13 taken in combination, the method comprising a step consisting of: Deactivate the main electromagnet (5) during the rotation of the turbomachine (T) so as to cancel said retention force (F) so as to allow the breaking of the bond of material solid between the foot part (11) and the head part (12).

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