Device for simultaneously determining the mechanical deformation of a part and the direction of laminar airflow around the part

Abstract

This disclosure relates to a device for the simultaneous determination (1) of fluid flow around a structural part and of the mechanical deformation of said structural part subjected to mechanical stresses, said device being intended to be fixed to a surface of said structural part, the device comprising: - fixed sensors (3) disposed on one face of a flexible substrate adapted to determine the mechanical deformation undergone by the part; - movable sensors (4) disposed on tabs formed by a cutout made in the flexible substrate adapted to determine the deformation undergone by the tab under the effect of the fluid flow. Fig. 2

Description

Title of the invention: Device for simultaneously determining the mechanical deformation of a part and the direction of laminar airflow around the part. Technical field

[0001] The present invention relates to the field of equipment fitted with sensors to determine the mechanical deformation and direction of an airflow.

[0002] More particularly, a device is proposed that is capable of simultaneously determining the deformation and direction of an airflow in real time in a flexible structural part such as the sail of a sailing ship or a solid part such as the mast of a sailboat. Previous technique

[0003] Technological advances have improved the performance of sails for both racing and recreational sailing. In particular, modeling and simulation work has enabled manufacturers to better understand the aerodynamic phenomena occurring around the sail during sailing and the forces applied to it. All this work shows that it is essential during sailing to know and continuously adjust the sail profile and settings to maintain course and speed according to wind direction and strength. In particular, it is essential to know the direction of the airflow in order to adjust the sail to optimize the aerodynamic conditions around the sail, thereby maximizing wind uplift and thus the sailboat's speed.

[0004] Fig. 1 represents a section and top view of a profiled mast 21 and a sail 22 subjected to an airflow 24 which is schematically represented by lines.

[0005] The sail 22 is generally made of a fiber-reinforced plastic film. It can be viewed as a flexible elastic membrane, some sides of which are connected to more rigid elements, namely spars and cables (not shown in [Fig. 1]). It undergoes deformation due to applied stresses from the wind and the forces exerted by the navigator during adjustments made via the spars and cables to adjust the sail profile according to weather conditions or the boat's point of sail. Continuously determining the sail profile in real time would allow the navigator to achieve optimal settings.

[0006] Furthermore, the interaction between the sail and the air flowing around or against a part of the sail is a coupled phenomenon, that is to say, the evolution of each of the two elements depends on that of the other. Thus, for example, the shape of the sail The performance of a boat depends on the airflow around it. Conversely, this flow depends on the shape of the sail. Therefore, to accurately determine the airflow regime around the sail, it is important to simultaneously determine the evolution of the sail's deformation and the evolution of the airflow around the sail.

[0007] Another element of a sailboat to consider during navigation is the mast that supports the sail. The mast 21 can be seen as a beam, generally in the form of a hollow tube, with a constant cross-section at the bottom and a cross-section that gradually decreases towards the top. It allows the sails to be hoisted and held aloft. When an airflow acts on the mast / sail assembly, there is a stagnation point 23 on the mast where the flow velocity is zero, as illustrated in [Fig. 1]. This location marks the separation of the flows on the lower and upper surfaces of the sail profile. The orientation of the mast 21 relative to the flow changes the location of the stagnation point. Accurate real-time determination of its location can be useful in measuring the airflow. Furthermore, the mast 21 is also subjected to mechanical stresses during its use.Its deformation during use can also influence the sail's profile and therefore disrupt the airflow. It is therefore also desirable to determine its deformation in real time during navigation to optimize boat trim.

[0008] To date, the assessment of airflow around the sail is determined using several telltales, one end of which is attached to different points on the sail. The telltales are pieces of fabric or wool that follow the wind flow. The skipper observes their orientation to correct the boat's heading and / or trim in order to maintain a good compromise between course and speed. If the telltales extend horizontally relative to the sail, the airflow is laminar, indicating that the sail is correctly positioned relative to the wind. Conversely, if the telltales are oriented upwards or downwards, the airflow is disturbed and not laminar over the sail, indicating to the navigator that sail trim and / or boat heading adjustment is necessary.However, this approximate solution is not always possible to implement, because the telltales are not visible to the navigator, for example in the dark or when weather conditions are bad.

[0009] A device for determining the regime and / or direction of a fluid flow near a sail is known from document FR0706196. This device comprises a flexible plate, one area of ​​which is fixed to the surface of the sail and another area of ​​which is free relative to the sail. The plate is extended by a telltale that can follow the airflow. A sensor is positioned in the free area of ​​the plate. It is flexible for determining the flow regime or its direction. However, such a device does not allow for measuring the stresses experienced by the sail, making the determination of the airflow regime incomplete.

[0010] Furthermore, the measuring device of document FR0706169 does not allow measurement of the airflow regime around the mast as well as the stresses applied to the structure of the mast.

[0011] In general, the proposed technical solutions are not compact enough to be integrated onto a mast. However, the instrumentation of the mast is crucial in order to precisely determine the location of the streamline separation point, which corresponds to the velocity stopping point.

[0012] There is therefore a need to provide a device which makes it possible to simultaneously determine the airflow regime near a structural element and the deformation of that structural element, and which is simple to implement, and suitable for optimal operation, even in severe environments, i.e. subjected to extreme conditions.

[0013] Another objective of the present disclosure is to propose a determination device that can be integrated with millimeter precision on the surface of an element not having a compatible support for electronic components, for example the flexible and light surface of a sail subjected to deformations and / or complex airflow, or the surface of a mast which has a substantially tubular shape, while being thin enough not to disturb the flows in order to provide reliable measurement data over a long measurement period. Technical solution

[0014] In order to improve the situation, a device is proposed for simultaneously determining fluid flow around a structural part and the mechanical deformation of said structural part subjected to mechanical stresses, said device being intended to be fixed on a surface of said structural part, the device comprising: - a flexible substrate adapted to be fixed to the surface of said structural part by conforming to the shape of said structural part so that a mechanical deformation of the part induces a mechanical deformation on the substrate; - at least one sensor disposed on one face of said substrate, said at least one sensor forming a fixed sensor adapted to determine the mechanical deformation undergone by the part; - at least one tab formed by a cut made in said substrate, said at least one tab having one edge fixed to the substrate and the other edges free relative to the substrate in order to allow the tab to flex under the effect of the fluid flow; - a sensor being disposed on each of the tabs, said sensor forming a mobile sensor adapted to determine the deformation undergone by the tab

[0015] The device of the present disclosure makes it possible to measure in real time and continuously the mechanical deformation of the part on which it is fixed but also the airflow circulating around this part.

[0016] Thus, the device of the present disclosure makes it possible to instrument different places of a part which is subjected to mechanical stresses and an airflow, such as the sail and / or the mast, to perform simultaneous measurements, for a given period, in real time, to determine the direction of the airflow around the part and the deformation of the part subjected to mechanical stresses.

[0017] The features described in the following paragraphs may optionally be implemented independently of each other or in combination with each other:

[0018] The substrate can be made of a polymeric material such as PET, PVC, PU, ​​Silicone or of a composite material such as a fiberglass or flax and polyester material, fiberglass or flax and epoxy.

[0019] The device can be in the form of a patch suitable for gluing to the surface of the part. The device is therefore ready to be fixed to the structural part and, with an optimized cost, it is therefore possible to consider fixing the devices in several places on the sail and mast, thus obtaining a measurement grid.

[0020] The sensors and the substrate can form a multilayer structure having a total thickness between 2 pm and 4000 pm.

[0021] According to one embodiment, the device may further include a communication interface enabling the transmission of signals from the sensors to a control system.

[0022] The sensors can consist of strain gauges capable of converting the deformation undergone by the structural part and the deformation undergone by the tongue into electrical signals.

[0023] Advantageously, the device may further include at least one auxiliary sensor selected from a group comprising a temperature sensor, a pressure sensor, and a humidity sensor. These auxiliary sensors are thus chosen to enable the real-time detection of a parameter (temperature, pressure, and / or humidity level, for example) that interferes with the measurement performed by the airflow and deformation sensors. The data from the mobile and fixed sensors can therefore be supplemented by data from the auxiliary sensors, making the extracted information more precise.

[0024] According to one embodiment, the device may include a fixed sensor and four mobile sensors arranged around said fixed sensor, said mobile sensors being positioned at 90° to each other, the facing mobile sensors being head-to-tail.

[0025] According to another embodiment, the device can include a plurality of mobile and fixed sensors to form a sensor network.

[0026] According to one embodiment, the network may include at least a first row of sensors (L1) comprising a row of alternating mobile and fixed sensors and at least a second row (L2) comprising a row of mobile sensors spaced apart by a distance E, said first row being offset by one sensor relative to the second row so that the mobile sensors are positioned in a staggered pattern between the two rows and the mobile sensors of the first row (L1) are opposite an empty location E of the second row, the mobile sensors being placed head-to-tail from one row to the other.

[0027] According to another aspect, it is proposed to use the aforementioned measuring device to determine simultaneously and continuously the deformation of a sail and / or a mast of a sailboat and the direction of the airflow around said sail and mast.

[0028] According to another aspect, it is proposed to use the aforementioned measuring device to simultaneously and continuously determine the deformation and the direction of the flow of a fluid around a structural element subjected to this flow. Brief description of the drawings

[0029] Other features, details and advantages will become apparent upon reading the detailed description below, Fig. 1

[0030] [Fig.l] [Fig.l] represents a schematic top view of a device for determining the airflow regime and deformation according to an embodiment, comprising a fixed sensor and a mobile sensor. Fig. 2

[0031] [Fig.2] [Fig.2] represents a schematic top view of a measuring device according to an embodiment comprising a fixed sensor and a moving sensor. Fig. 3

[0032] [Fig.3] [Fig.3] represents a schematic perspective view of a measuring device according to another embodiment comprising a fixed sensor and four mobile sensors around the fixed sensor. Fig. 4

[0033] [Fig.4] [Fig.4] represents a schematic perspective view of a measuring device according to another embodiment comprising a network of mobile sensors and a network of fixed sensors. Fig. 5

[0034] [Fig.5] [Fig.5] represents a schematic view of a sailboat equipped with several measuring devices which are arranged on the sail and the mast of the sailboat. Description of the implementation methods

[0035] Several non-limiting examples of embodiments are described in detail below. In the various figures, identical reference numerals indicate identical or similar elements. Some dimensions may be exaggerated for illustrative purposes.

[0036] The terms "upper" and "lower" in this description refer to an arrangement substantially along the vertical direction, considering a direction along the length of the mast.

[0037] With reference to [Fig.2], a measuring device 1 is presented according to an embodiment adapted to be fixed on the outer surface of a structural part, for example a sail and / or a mast.

[0038] It includes a substrate 2 which may include a layer of material or a stack of layers of material.

[0039] In the example of [Fig.2], it has a substantially rectangular shape. But it can have another geometric shape chosen according to the area on which it is fixed.

[0040] As can be clearly seen here, the substrate 2 can extend longitudinally between a front end and a rear end, along a longitudinal axis Al in a straight line or at least along a longitudinal axis Al.

[0041] In practical applications, the size of the substrate 1 can be chosen according to the area on which it is fixed.

[0042] According to one embodiment, the dimensions of the substrate may be as follows: the length is between 10 and 1000 mm, the width is between 10 and 1000 mm. The dimensions of this strip are adapted according to the number of sensors desired.

[0043] The substrate is in the form of a flexible strip made of a polymer insulating material, which may be a thermosetting or thermoplastic material. Thus, when the substrate is fixed to the part, it conforms to the shape of the part, so that the mechanical deformation of the part causes a mechanical deformation in the substrate. The substrate may be made of a polymeric material such as PET, PVC, PU, ​​silicone or in a composite material such as a fiberglass or flax and polyester material, fiberglass or flax and epoxy.

[0044] The substrate has a thickness between Ipm and 3000pm, preferably between 1pm and 500pm.

[0045] According to one embodiment, the device may be in the form of a patch intended to be fixed to the surface of the part. The part may, for example, be a flexible part such as a sail, or a solid part with a complex geometric shape, for example a mast, a profiled part, for example an aeronautical part, an automotive part or a wind turbine part.

[0046] By patch, we mean a device having an adhesive surface or areas of adhesive surfaces.

[0047] The fact that the device of the present disclosure is in the form of a patch leads to many advantages.

[0048] This patch design first allows for limited intrusion into the part being monitored, thus preserving the part's integrity. In particular, the presence of the device must not disrupt the interaction between the part and the airflow around it, which could lead to erroneous measurements. The patch design allows for the thinnest possible thickness to avoid disturbing deformations and airflow around the element. In other words, the part's settings and performance must not be affected by the onboard instrumentation.

[0049] The use of the device in patch form makes it easier to integrate it onto parts having a three-dimensional geometric shape or made of a material not compatible with the fixing of electronic components.

[0050] Using the device in patch form also allows for the distribution of several devices over different areas of the part to be inspected. A judicious distribution of the measuring devices over the different areas of the part to be monitored makes it possible to collect, on the one hand, local information at the level of each measuring device, and on the other hand, general information by considering the information from all the measuring devices, thus providing overall information about the part.

[0051] The device comprises electrically conductive layers deposited on the substrate, which may be an insulating layer. The assembly thus forms a multilayer structure. The electrically conductive layers form the sensors.

[0052] Electrically conductive layers are deposited on one face of the substrate, for example by screen printing, printing, or thin-film deposition, to form sensors. The number of layers can be, for example, between 1 and 8. Each layer can have a thickness between 1 nm and 3000 nm. The sensors are made, for example, by an assembly of strain gauges.

[0053] The sensors have a thickness of the order of 1 to 600 pm, the substrate having a thickness of between 1 and 3000 pm, the measuring device thus has a total thickness of between 2 pm and 4000 pm.

[0054] The device has a thin profile, meaning it is lightweight, flexible, and conformable, making it particularly suitable for attachment to a sail. For example, it can be glued to the element. When used on a sailboat, it can be glued to the sail during sailmaking, in various areas of the sail. It can also be glued along the sailboat's mast. Furthermore, due to its thin profile, the measuring device is substantially flush with the surface of the element to which it is attached, so that its presence does not disrupt the airflow around the element.

[0055] The device of this disclosure is thus of a low thickness so that when fixed to the structural part, it forms a substantially continuous surface with the part's surface. In other words, the measuring device does not disrupt the airflow around the part.

[0056] By way of example, each sensor consists of, for instance, four gauges and two electrical connection terminals for the signal output. The sensor's operation can be based on the known principle of the strain gauge.

[0057] According to one embodiment, the two electrical connection terminals are connected to a communication interface to transmit the signal to an external acquisition system. In the case of a rosette-type configuration, the sensor may comprise more than two terminals that are connected to the communication interface to transmit the signal to the external acquisition system.

[0058] According to another embodiment, the sensors are connected to the acquisition system by electrically conductive wires having a first end in contact with at least one of the conductive layers and a second end accessible from outside the device, thus allowing the transmission to the outside of the device of a signal representative of a measured physical characteristic.

[0059] The acquisition system can be a conventional computer system comprising memory, a processor with a processing unit, and a display unit. In the context of an application of the device to determine the deformation and airflow of the sails and mast of a sailboat, the control system can, for example, be a computer navigation system into which a module for acquiring and processing data from the device's sensors has been loaded.

[0060] Both wired and wireless signal transmission solutions can be adapted according to needs and constraints. For example, it is possible to combine the two types of transmission depending for example on the location of the measuring device relative to the central unit.

[0061] In order to be able to simultaneously determine the deformation undergone by the part subjected to stresses and the direction of the airflow near this structural part, the device of the present disclosure includes fixed sensors and mobile sensors dedicated respectively to measuring the mechanical deformation of the part and the direction of the airflow around the part which can be for example a sailboat sail, or the sailboat mast.

[0062] According to an embodiment illustrated in [Fig. 2], the device comprises a first sensor 3 which is attached to the flexible substrate 2, which is itself intended to be fixed to the structural part, for example, the mast or sail of a boat. The substrate 2 is therefore fixed relative to the structural part, and the first sensor 3, which is fixed to the substrate, is also fixed relative to the structural part. This first sensor 3 is called the fixed sensor. Thanks to the thin thickness of the device and its flexibility, any mechanical deformation induced in the structural part also causes a mechanical deformation in the substrate, which the fixed sensor 3 can detect by generating an electrical signal.

[0063] The device 1 further includes a second sensor 4 which is fixed to a tab 5 formed by a cutout 6 made directly in the substrate 2. The tab 5 includes a fixed edge 5.1 which is integral with the substrate and the other free edges 5.2, 5.3, 5.4 relative to the substrate in order to allow the tab to be flexible and follow the movement of the airflow. The tab 5, subjected to the airflow, is flexible relative to the substrate 2 which is fixed to the structural part. Thus, the sensor 4 which is fixed to the flexible tab 5 is movable relative to the substrate 2. This second sensor is called the movable sensor 4.

[0064] The fixed sensor 3 and the mobile sensor 4 are each made up of similar strain gauges but have different functionalities depending on whether they are mobile or fixed.

[0065] The fixed sensor 3, which is attached to the structural part via the substrate 2, undergoes the mechanical deformation of the structural part and can therefore measure it. It is particularly possible to arrange several sensors along predefined axes, for example at 90° to each other, to detect different types of stress, for example torsion, compression, or shear.

[0066] The movable sensor 4 can move in space via the flexible tab 5, following the direction of the airflow. Thus, the action of an external constraint due to the airflow will have a direct effect on the displacement of the movable sensor 4. In the case of [Fig. 2], the operating principle of the movable sensor 4 is as follows. When the wind direction, indicated by an arrow labeled F2 in [Fig. 2], is Opposite the fixed edge 5.1 of the flexible tab 4, the tab will detach. The moving sensor 4 will therefore detect the movement of the flexible tab 5. Conversely, when the wind direction is towards the fixed edge 5.1, indicated by an arrow labeled Fl in [Fig. 2], the tab 5 remains stationary and will not detach. The moving sensor 4 attached to the flexible tab 5 will not detect the movement. The stresses applied by the wind to the tab 5 are representative of the airflow direction. These stresses, to which the tab is subjected, generate deformations in the tab, which are detected by the moving sensor 4 attached to the tab. The tab deformations are, for example, converted into electrical signals by a strain gauge.

[0067] Figure 3 illustrates an example of an embodiment of the determination device 10 simultaneous mechanical deformation of a structural part and airflow over the structural part.

[0068] The determination device 10 comprises a fixed sensor 3 and four movable sensors 4.1, 4.2, 4.3, 4.4 arranged at 90° angles to each other around the movable sensor 3. The wind direction, indicated by an arrow F4, is opposite to the fixed edge of the movable sensor 4.1 and lifts the tab to which the movable sensor 4.1 is attached. The latter will detect the movement of the associated tab. The two sensors 4.2, 4.4, perpendicular to the wind direction, will detect a torsional movement of the associated tabs.

[0069] The device in [Fig.3] thus makes it possible to detect the change in wind direction thanks to the arrangement of several mobile sensors oriented in different directions.

[0070] According to another embodiment, the measuring device may include a network of mobile sensors and a network of fixed sensors, thus making it possible to determine in real time the orientation of the airflow, and in particular the variation of the direction of the airflow.

[0071] Figure 4 illustrates an example of an arrangement of a plurality of mobile sensors and fixed sensors to form a sensor network. The mobile sensors are arranged to form sensor lines. Each line is offset by one sensor from the line before and after it, so the mobile sensors are staggered from one line to the next. Furthermore, the sensors are placed end-to-end from one line to the next. Every other line consists of fixed sensors positioned between two mobile sensors.

[0072] In the example of [Fig. 4], the referenced line L1 comprises a row of alternating mobile sensors 4 and fixed sensors 3. The referenced line L2 comprises a row of mobile sensors spaced far enough apart to define an empty slot E for receiving a mobile sensor. Line L1 and line L2 are offset from each other so that the mobile sensors of line L1 are opposite the empty location E and the fixed sensors of line L2 are opposite the mobile sensors of line L1.

[0073] The device illustrated in Figures 2-4 is particularly well-suited for instrumenting structural parts such as the sails and mast of a sailboat. A judicious distribution of several devices on the sails and / or mast makes it possible to simultaneously determine their profile and the wind flow in their vicinity in real time, allowing the navigator to adjust the settings in order to maintain the sailboat's course and speed.

[0074] Figure 5 illustrates a schematic view of a sailboat placed in a coordinate system (X, Y, Z), with X pointing towards the front of the boat, Z along the mast 40 and pointing upwards, and the origin of the coordinate system located at the base of the mast. The boat is equipped with two sails 20, 30.

[0075] Sails are generally made using synthetic fiber fabrics that are sized and oriented to achieve an optimal sail shape for sailing, as close as possible to the simulated design. However, the 3D profile of sails deforms according to the adjustments made by the sailor and the stresses encountered at sea. This deformation, which evolves over time, can be schematically represented by the presence of a "hollow" that moves along the sail.

[0076] In the example illustrated in [Fig. 5], several determining devices are distributed on both faces of the two sails 20, 30. In [Fig. 5], devices 102, 103, 104, 106, and 107 are visible on one of the faces. The positioning and number of devices can be adjusted according to the requirements and the size of the sails. The devices can be attached to the sail by gluing or using adhesive tape. Attaching the devices to the sail can be done during the sail manufacturing process.

[0077] The fixed sensors 3 of each of the determining devices are fixed relative to the sail via the substrate and can measure the deformation undergone by the sail. The fixed sensors make it possible to determine in real time the deformation of the sail and therefore the position of the sail's draft.

[0078] The mobile sensors 4 of each of the devices are mobile relative to the substrate. They allow the airflow around the sail to be determined in real time.

[0079] The simultaneous collection of signals from the sensors allows the navigator to adjust the sail and correct the direction of the sailboat in order to maintain a good compromise between heading and speed.

[0080] Regarding mast 40 of the sailboat, as indicated above, it is also useful to determine in real time the location of the point or stop line on the mast where the flow velocity is zero and its mechanical deformation is linked to mechanical stresses during use.

[0081] In the example illustrated in [Fig. 5], several devices are distributed at different heights on the mast 40. The positioning and number of devices can be adjusted according to the requirements and the size of the mast. In the example in [Fig. 5], three devices 101, 105, and 107 are positioned on the mast. The determining devices can be attached to the mast by gluing or using adhesive tape. The devices can be attached to the mast during the manufacturing of the mast.

[0082] Fixed sensors allow the mechanical deformation of the mast to be determined, while mobile sensors allow the direction of the airflow to be determined.

[0083] According to a particular embodiment, one of the measuring devices on the mast can be that of [Fig. 4], which comprises a network of determination devices with a specific arrangement of the movable sensors in a back-to-back configuration. It is thus possible to locate the stop line on the mast where the flow velocity is zero. Its location is indicated when the tabs of the movable sensors in the back-to-back configuration are raised in opposite directions. This configuration is shown in [Fig. 4] by the sensors DI belonging to line L2 and the sensors D2 belonging to line L1, located on either side of the stop line, which is a black line L0. In the case where there is an established airflow over the mast or sail in a certain direction, only the tabs whose edges attached to the substrate are opposite to the wind direction are raised. In [Fig. 4], the direction of the established flow is indicated by arrow F3.The mobile sensor D4, under the action of the wind, is lifted while the mobile sensor D3 remains stationary.

[0084] According to one embodiment, the determination device may include other types of sensors made on the same substrate. By way of example, these auxiliary sensors may be a pressure sensor, a temperature sensor, or a humidity sensor.

[0085] The device is described here in the context of use on a sailboat to determine in real time the stresses exerted on the sail and mast as well as the airflow around the sail and mast in order to help the navigator adjust the sails and mast to optimize navigation.

[0086] It is understood from the description that the device of the present disclosure can also be used to simultaneously determine the deformation and direction of flow of a fluid in the vicinity of any structural element.

[0087] According to one embodiment, each device further comprises a communication interface for continuously transmitting the measurement data collected by each sensor to an acquisition system. The device can Perform a series of measurements at a high rate, for example, with an interval of less than 10 seconds between successive measurements. High temporal resolution can be achieved with a measurement rate of, for example, every 4 seconds, or even less than one second. At a high frequency, it is thus possible to determine the sail profile and the airflow around the sail and mast in real time. Data acquisition is controlled by dedicated software.

[0088] According to another embodiment, the acquisition control system may include a data recorder having a link interface connecting to the sensors of the devices.

[0089] The acquisition system can be, for example, a computer navigation system in which is integrated a computing module configured to process the signals from the various mobile sensors, fixed sensors and auxiliary sensors to generate information representative of the settings to be made by the crew to adjust the sail and the mast according to the direction of the wind and the deformation of the sail, the location of the stopping line and the deformation of the mast.

[0090] The description of the embodiments presented above is provided as examples to describe one or more ways of obtaining the device, without limitation. Furthermore, each part of this disclosure is not limited to the corresponding embodiment, and various variations may be made within the same technical framework.

Claims

Demands

1. Device for simultaneously determining (1) fluid flow around a structural part and the mechanical deformation of said structural part subjected to mechanical stresses, said device being intended to be fixed to a surface of said structural part, the device comprising: - a flexible substrate (2) adapted to be fixed to the surface of said structural part by conforming to the shape of said structural part so that a mechanical deformation of the part induces a mechanical deformation on the substrate; - at least one sensor (3) disposed on a face of said substrate, said at least one sensor forming a fixed sensor (3) adapted to determine the mechanical deformation undergone by the part; - at least one tab (5) formed by a cut (6) made in said substrate (2), said at least one tab (5) having one edge fixed (5.1) to the substrate (2) and the other edges free (5.2, 5.3, 5.4) relative to the substrate (2) in order to allow the tab (5) to flex under the effect of the fluid flow; - a sensor (4) being disposed on each of the tabs, said sensor forming a movable sensor (4) adapted to determine the deformation undergone by the tab.

2. Device according to claim 1, wherein the substrate is made of a polymeric material such as PET, PVC, PU, ​​Silicone or of a composite material such as a fiberglass or flax and polyester material, fiberglass or flax and epoxy.

3. Device according to claim 1 or 2, wherein the device is in the form of a patch suitable for being glued onto the surface of the part.

4. Device according to any one of claims 1 to 3, wherein the sensors (3, 4) and the substrate form a multilayer structure having a total thickness between 2 pm and 4000 pm.

5. Device according to any one of the preceding claims, further comprising a communication interface for transmitting signals from the sensors to a control system.

6. Device according to any one of the preceding claims, wherein the sensors consist of strain gauges capable of converting the deformation undergone by the structural part and the deformation undergone by the tongue into electrical signals.

7. Device according to any one of the preceding claims, further comprising at least one auxiliary sensor selected from a group comprising a temperature sensor, a pressure sensor, a humidity sensor.

8. Device according to any one of the preceding claims, comprising a fixed sensor (3) and four mobile sensors (4.1, 4.2, 4.3, 4.4) arranged around said fixed sensor, said mobile sensors being positioned at 90° to each other, the facing mobile sensors being head-to-tail.

9. Device according to any one of the preceding claims, comprising a plurality of mobile sensors and fixed sensors to form a sensor network.

10. Device according to claim 9, wherein said network comprises at least a first row of sensors (L1) comprising a row of alternating moving and fixed sensors and at least a second row (L2) comprising a row of moving sensors spaced apart by a distance E, said first row being offset by one sensor relative to the second row such that the moving sensors are positioned in a staggered pattern between the two rows and the moving sensors of the first row (L1) are opposite an empty location E of the second row, the moving sensors being placed head-to-tail from one row to the other.

11. Use of a device according to any one of claims 1 to 10 for simultaneously and continuously determining the deformation of a sail and / or mast of a sailboat and the direction of the airflow around said sail and mast.

12. Use of a device according to any one of claims 1 to 10 to simultaneously and continuously determine the deformation and direction of the flow of a fluid around a structural element subjected to this flow.

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