EP1685371A1 - Attack angle probe - Google Patents

Attack angle probe

Info

Publication number
EP1685371A1
EP1685371A1 EP04818835A EP04818835A EP1685371A1 EP 1685371 A1 EP1685371 A1 EP 1685371A1 EP 04818835 A EP04818835 A EP 04818835A EP 04818835 A EP04818835 A EP 04818835A EP 1685371 A1 EP1685371 A1 EP 1685371A1
Authority
EP
European Patent Office
Prior art keywords
skin
incidence
air flow
measuring
probe according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP04818835A
Other languages
German (de)
French (fr)
Inventor
Joel Thales Intellectual Property CHOISNET
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Thales SA
Original Assignee
Thales SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Thales SA filed Critical Thales SA
Publication of EP1685371A1 publication Critical patent/EP1685371A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01PMEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P5/00Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft
    • G01P5/02Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring forces exerted by the fluid on solid bodies, e.g. anemometer
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01LMEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L5/00Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01LMEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L7/00Measuring the steady or quasi-steady pressure of a fluid or a fluent solid material by mechanical or fluid pressure-sensitive elements
    • G01L7/02Measuring the steady or quasi-steady pressure of a fluid or a fluent solid material by mechanical or fluid pressure-sensitive elements in the form of elastically-deformable gauges
    • G01L7/08Measuring the steady or quasi-steady pressure of a fluid or a fluent solid material by mechanical or fluid pressure-sensitive elements in the form of elastically-deformable gauges of the flexible-diaphragm type
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01LMEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L9/00Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
    • G01L9/0041Transmitting or indicating the displacement of flexible diaphragms
    • G01L9/0051Transmitting or indicating the displacement of flexible diaphragms using variations in ohmic resistance
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01PMEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P13/00Indicating or recording presence, absence, or direction, of movement
    • G01P13/02Indicating direction only, e.g. by weather vane
    • G01P13/025Indicating direction only, e.g. by weather vane indicating air data, i.e. flight variables of an aircraft, e.g. angle of attack, side slip, shear, yaw
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01PMEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P5/00Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft
    • G01P5/14Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring differences of pressure in the fluid

Definitions

  • the invention relates to an incidence probe intended to measure the incidence of an air flow circulating outside a skin.
  • the invention finds particular utility in aeronautics for measuring the incidence of an aircraft. It is understood that the invention is not limited to the aeronautical field.
  • the invention could be implemented, for example, in a wind tunnel to determine the direction of an air flow or even in a weather station to determine the wind direction.
  • the invention will be described in connection with an incidence probe mounted on the skin of an aircraft.
  • the incidence of an aircraft is defined as the angle of the air speed vector with respect to a horizontal plane of the aircraft.
  • the wander of an aircraft is defined as being the angle of the air speed vector with respect to a vertical plane, generally a plane of symmetry, of the aircraft.
  • the incidence and skid are of great importance for the piloting of the aircraft. In fact, they determine with speed, lift and drag, that is to say the forces exerted by the air on the aircraft. Their knowledge is fundamental for flight safety and particularly in the take-off and landing phases during which the speed of the aircraft is low and the incidence high, ie close to stall. As for the slip, it must remain well controlled. Aircraft are equipped with incidence and wander sensors to measure these parameters. In practice, the same probe can be used either to measure the incidence or to measure the slip according to its location on the skin of the aircraft. This type of probe locally measures the direction of air relative to the skin of the aircraft. This is called local incidence. In the following description, the destination of the probe will not be distinguished.
  • incidence probe There are two main families of incidence probes.
  • the first family is formed by so-called mobile probes. They include a movable element orienting in the direction of the air flow. This movable element is generally a pallet movable in rotation about an axis perpendicular to the skin of the aircraft.
  • the incidence measurement is carried out in measuring the angular position of the movable element around its axis of rotation. These probes exhibit friction between the movable element and the skin of the aircraft. This friction disturbs the measurement all the more as the speed of the air flow is low.
  • the second family is formed by so-called fixed probes. They have a fixed body protruding from the skin of the aircraft.
  • the fixed body is aerodynamically profiled and has several pressure taps. The pressure measurements made by means of the pressure taps make it possible to calculate the incidence of the air flow relative to the fixed body.
  • These probes do not exhibit friction but are vulnerable at the level of the pressure taps which can become clogged with water or during the passage of the aircraft through dust clouds, making pressure measurements impossible and therefore the determination of the impact.
  • Certain mobile probes may include pressure taps in order to improve the orientation of the mobile element in the direction of the air flow. They then combine the drawbacks of the two families of probes previously described.
  • the invention aims to overcome the drawbacks of the two families of probes by proposing a new principle of fixed incidence probe, therefore without friction, and without pressure measurement.
  • the subject of the invention is an incidence probe, intended to measure the incidence of an air flow circulating outside a skin, characterized in that it comprises a body located at the outside of the skin and means for measuring a force exerted by the air flow on the body.
  • FIG. 1 represents a body forming a sensitive part to an air flow from an incidence probe
  • Figures 2a and 2b show a first embodiment of the invention in which means for measuring a force exerted by the air flow on the body include strain gauges
  • Figures 3a and 3b show a second embodiment of the invention in which the means for measuring a force exerted by the air flow on the body include electrodes forming capacitors
  • Figure 4 shows the incidence probe shown in Figure 1 to which were added parietal pressure taps.
  • the incidence probe shown in FIG. 1 comprises a body 1 situated outside a skin 2, for example that of an aircraft.
  • the body 1 forms the sensitive part of the incidence probe.
  • the direction of an air flow, materialized by arrow 3, which one wishes to determine by means of the incidence probe is parallel to the skin 2.
  • the body 1 is symmetrical of revolution around an axis 4 substantially perpendicular to the surface of the skin 2.
  • the body 1 is a cylinder of axis 4.
  • the cylinder will also bear the reference 1.
  • the cylinder 1 is subjected to aerodynamic forces created by the air flow. Due to the symmetry of revolution of the cylinder 1, the result of these aerodynamic forces is the drag 5 whose direction is identical to the direction 3 of the air flow.
  • the angle of attack sensor comprises means for measuring a force exerted by the air flow on the body 1, in other words, means for measuring the drag 5.
  • means for measuring the drag 5 By measuring the direction of the drag 5, one obtains directly l incidence of the air flow relative to the probe due to the identity of direction between that of the air flow and that of the drag 5.
  • the drag 5 is balanced by the reaction forces of a plate 6 ensuring the attachment of the body 1 to the skin 2.
  • the means for measuring a force comprise elastic means holding the body 1 secured to the skin 2, and means for measuring the relative position of the body 1 relative to the skin 2.
  • a plate 6 forms the elastic means holding the body 1 integral with the skin 2.
  • the modification of the relative position of the body 1 relative to the skin 2 is representative of drag 5 and therefore direction of the air flow. By measuring this modification, it is therefore possible to determine the incidence of the air flow relative to the probe. It is of course possible to give the body 1 a completely different shape than that shown in FIG. 1.
  • the body 1 can for example form the body of another probe mounted on an aircraft, such as for example a Pitot tube or a total temperature probe. Due to the absence of symmetry of revolution of this probe, the result of the aerodynamic forces exerted by the air flow on the body 1 may have a direction different from that of the air flow. The result of the aerodynamic forces is then the sum of the drag and the lift.
  • the incidence probe comprises a counterweight 7 fixed to the body 1 and arranged so that the center of gravity of an assembly formed by the body 1 and the counterweight 7 is substantially located at the surface of the skin 2.
  • the counterweight 7 is visible on the Figure 2a.
  • the modification of the relative position of the body 1 relative to the skin 2 is then essentially done by a rotation around the center of gravity of the assembly.
  • the position of the center of gravity of the assembly at the level of the skin 2 makes it possible to limit the sensitivity of the measurement of the relative position of the body with respect to the skin 2 to accelerations of the aircraft, in particular those whose direction is perpendicular to the axis 4 of the body 1.
  • the means for measuring a force are distributed symmetrically around the axis 4 when the body 1 is cylindrical or more generally around an axis of inertia of the body 1, axis perpendicular to the surface of the skin 2.
  • FIG. 2a shows the first embodiment without the action of the air flow .
  • the elastic means 6 are fixed on the one hand to the skin 2 and on the other hand to the body 1.
  • the elastic means 6 have for example the shape of a washer with an axis 4.
  • the strain gauge 10a is fixed on the elastic means 6 on the inner side of the skin 6.
  • the measurement of the deformation of the elastic means 6 is carried out by measuring the difference in resistance value of the deformation gauge 10a between a reference position such as that shown in the figure 2a and a position where the body 1 is subjected to the action of the air flow 3 as shown in FIG. 2b.
  • the position measurement means comprise several strain gauges distributed symmetrically around the axis 4. In FIGS. 2a and 2b two gauges have been shown and they bear the marks 10a and 10b. The resistance variations of two strain gauges 10a and 10b arranged symmetrically are opposite.
  • FIG. 2b shows the deformation of the elastic means 6 in a direction carried by the plane of Figure 2b and the two deformation gauges 10a and 10b arranged in the same plane.
  • FIGS. 3a and 3b represent a second embodiment of the position measurement means. More specifically, the position measuring means comprise a first electrode 11 secured to the body 1 and at least a second electrode 12a secured to the skin 2. The two electrodes 11 and 12a form a capacity varying according to the modification of the position relative of the body 1 with respect to the skin 2.
  • FIG. 3a represents the second embodiment without the action of the air flow.
  • the elastic means 6 are fixed on the one hand to the skin 2 and on the other hand to the body 1 for example by means of the first electrode 11.
  • the elastic means 6 have for example as in FIGS.
  • the position measuring means advantageously include, several second electrodes distributed symmetrically around the axis 4.
  • FIGS. 3a and 3b two second electrodes have been shown and they bear the marks 12a and 12b.
  • the capacitance values between on the one hand the electrodes 11 and 12a and between on the other hand the electrodes 11 and 12b vary in opposite fashion. This allows, as in the first embodiment, to increase the gain in the position measurement.
  • the incidence probe comprises two identical grids, transparent and having opaque lines. One of these grids is integral with the body 1 and the other with the skin 2. the two grids are placed opposite one another. A light ray is passed through the two grids and the intensity of the ray downstream of the two grids is analyzed.
  • the intensity measured downstream of the grids is maximum and when the opaque lines of the two grids are in opposition the intensity is minimal.
  • the measurement of the intensity makes it possible to determine the relative position of the body 1 relative to the skin 2 of the aircraft. It is possible to have, secured to the skin 2, both means emitting the light ray and means for analyzing its intensity downstream of the two grids, by placing a mirror secured to the body 1 on the optical path of the light ray.
  • the body 1 comprises reheating means in order to avoid the formation of frost on the body 1. The formation of frost is likely to occur during flights of the aircraft at high altitude.
  • the heating means comprise for example a heating wire placed inside the body 1 and supplied by a source of electric voltage, or alternatively means allowing the circulation of a heat-transfer fluid inside the body 1.
  • the probe includes means for determining the direction and intensity of the force 5 exerted by the air flow on the body 1.
  • the direction of the force gives the local incidence of the air flow by ratio to the probe and the intensity of the effort makes it possible to determine the speed of the air flow.
  • the force is proportional to the density of the air and to the square of the speed of the air flow.
  • the coefficient of proportionality is determined by the geometry of the body 1.
  • the density of the air can be known by means external to the probe such as for example by means of an altimeter. FIG.
  • an incidence probe advantageously comprising at least one pressure tap 20 or 21 placed on the skin 2 near the body 1 and more precisely on the plate 6.
  • a pressure tap 20 or 21 makes it possible to determine the static pressure Ps of the air flow surrounding the probe.
  • the position of the pressure tap 20 or 21 is defined so as not to disturb the deformation of the plate 6 when the body 1 is subjected to a force 5.
  • the pressure tap is generally disposed at the periphery of plate 6.
  • Such a probe carrying out in the same equipment the incidence and static pressure measurements makes it possible to obtain, associated with another multifunction probe measuring the pressure and the total temperature, such as that described in the patent application.
  • FR 2 823 846 all aerodynamic parameters of the aircraft, with the exception of sideslip.
  • a system comprising a multifunction probe measuring the pressure and the total temperature associated with 2 probes, in accordance with the present invention, measuring the incidence and the static pressure, the latter 2 probes being located symmetrically with respect to the vertical plane of symmetry of the airplane (right side and left side) allows to calculate the skid and to get rid of its influence.
  • Patent application FR 2 817 044 shows how, from 2 local incidence measurements, it is possible to calculate the true incidence and wander of the aircraft (upstream infinite parameters), and then to carry out all the desired corrections on the pressure measurements in depending on the incidence and wander.
  • the incidence probe comprises two pressure taps 20 and 21 arranged symmetrically with respect to an axis 22 tangent to the skin 2, the tangent axis 22 being concurrent with the axis 4.
  • the incidence probe comprises further means for pneumatically mixing the air taken off by the two pressure taps 20 and 21.
  • the static pressure Ps is then determined from the pneumatic mixture.
  • the tangent axis 22 is materialized on the incidence probe, for example by means of a marking.
  • the probe is oriented around its axis 4 so that the axis 22 coincides with the direction of the air flow surrounding the incidence probe when the incidence of the aircraft is void.
  • the body 1 can be rigid, that is to say very little deformable with respect to the means for measuring a force described with the aid of FIGS. 2a, 2b , 3a and 3b. Alternatively, the body 1 can be deformable under the action of the air flow.
  • the means for measuring a force 5 exerted by the air flow on the body 1 comprise means for measuring the deformation of the body 1 itself.
  • These deformation measuring means comprise for example at least one deformation gauge fixed to the body 1 and measuring its bending under the effect of the air flow.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Aerodynamic Tests, Hydrodynamic Tests, Wind Tunnels, And Water Tanks (AREA)
  • Measuring Fluid Pressure (AREA)

Abstract

The invention relates to an attack angle probe used to measure the attack angle of a circulating air flow outside a skin. The invention is particularly suitable for use in the aeronautics industry, where it can be used to measure the attack angle of an aircraft. According to the invention, the attack angle probe comprises a body (1) which is located outside the skin (2) and means for measuring an effort (5) exerted on the body (1) by the air flow.

Description

Sonde d'incidence Incidence probe
L'invention se rapporte à une sonde d'incidence destinée à mesurer l'incidence d'un flux d'air circulant à l'extérieur d'une peau. L'invention trouve une utilité particulière en aéronautique pour mesurer l'incidence d'un aéronef. Il est bien entendu que l'invention n'est pas limitée au domaine aéronautique. On pourrait mettre en oeuvre l'invention, par exemple, dans une soufflerie pour déterminer la direction d'un flux d'air ou encore dans une station météorologique afin de déterminer la direction du vent. Néanmoins l'invention sera décrite en rapport avec une sonde d'incidence montée sur la peau d'un aéronef. On définit l'incidence d'un aéronef comme étant l'angle du vecteur vitesse de l'air par rapport à un plan horizontal de l'aéronef. De même, on définit le dérapage d'un aéronef comme étant l'angle du vecteur vitesse de l'air par rapport à un plan vertical, généralement un plan de symétrie, de l'aéronef. L'incidence et le dérapage sont d'une grande importance pour le pilotage de l'aéronef. En effet ils déterminent avec la vitesse, la portance et la traînée, c'est à dire les forces exercées par l'air sur l'aéronef. Leur connaissance est fondamentale pour la sécurité du vol et particulièrement dans les phases de décollage et d'atterrissage pendant lesquelles la vitesse de l'aéronef est faible et l'incidence élevée, c'est à dire proche du décrochage. Le dérapage doit, quant à lui, rester bien maîtrisé. Les aéronefs sont équipés de sondes d'incidence et de dérapage pour la mesure de ces paramètres. Dans la pratique une même sonde peut être utilisée soit pour mesurer l'incidence soit pour mesurer le dérapage suivant son emplacement sur la peau de l'aéronef. Ce type de sonde mesure localement la direction de l'air par rapport à la peau de l'aéronef. On parle alors d'incidence locale. Dans la suite de la description on ne distinguera pas la destination de la sonde. Il est bien entendu que l'invention s'applique aussi bien aux sondes d'incidence qu'aux sondes de dérapage. On appellera par la suite ce type de sonde : sonde d'incidence. II existe deux familles principales de sondes d'incidence. La première famille est formée par des sondes dites mobiles. Elles comportent un élément mobile s'orientant dans la direction du flux d'air. Cet élément mobile est généralement une palette mobile en rotation autour d'un axe perpendiculaire à la peau de l'aéronef. La mesure d'incidence est réalisée en mesurant la position angulaire de l'élément mobile autour de son axe de rotation. Ces sondes présentent du frottement entre l'élément mobile et la peau de l'aéronef. Ce frottement perturbe d'autant plus la mesure que la vitesse du flux d'air est faible. En effet à basse vitesse, les forces aérodynamiques s'exerçant sur l'élément mobile sont faibles et ont du mal à vaincre le frottement. De plus, il est nécessaire d'assurer l'étanchéité de la sonde au niveau de la jonction entre la palette mobile et la peau de l'aéronef. La deuxième famille est formée par des sondes dites fixes. Elles comportent un corps fixe proéminent par rapport à la peau de l'aéronef. Le corps fixe est aerodynamiquement profilé et comporte plusieurs prises de pression. Les mesures de pression réalisées au moyen des prises de pression permettent de calculer l'incidence du flux d'air par rapport au corps fixe. Ces sondes ne présentent pas de frottement mais sont vulnérables au niveau des prises de pression qui peuvent se boucher avec de l'eau ou lors du passage de l'aéronef dans des nuages de poussière, rendant impossible les mesures de pression et donc la détermination de l'incidence. Certaines sondes mobiles peuvent comporter des prises de pression afin d'améliorer l'orientation de l'élément mobile dans la direction du flux d'air. Elles cumulent alors les inconvénients des deux familles de sondes précédemment décrites. L'invention a pour but de pallier les inconvénients des deux familles de sondes en proposant un nouveau principe de sonde d'incidence fixe, donc sans frottement, et sans prise de pression. A cet effet l'invention a pour objet une sonde d'incidence, destinée à mesurer l'incidence d'un flux d'air circulant à l'extérieur d'une peau, caractérisée en qu'elle comporte un corps situé à l'extérieur de la peau et des moyens de mesure d'un effort exercé par le flux d'air sur le corps.The invention relates to an incidence probe intended to measure the incidence of an air flow circulating outside a skin. The invention finds particular utility in aeronautics for measuring the incidence of an aircraft. It is understood that the invention is not limited to the aeronautical field. The invention could be implemented, for example, in a wind tunnel to determine the direction of an air flow or even in a weather station to determine the wind direction. However, the invention will be described in connection with an incidence probe mounted on the skin of an aircraft. The incidence of an aircraft is defined as the angle of the air speed vector with respect to a horizontal plane of the aircraft. Similarly, the wander of an aircraft is defined as being the angle of the air speed vector with respect to a vertical plane, generally a plane of symmetry, of the aircraft. The incidence and skid are of great importance for the piloting of the aircraft. In fact, they determine with speed, lift and drag, that is to say the forces exerted by the air on the aircraft. Their knowledge is fundamental for flight safety and particularly in the take-off and landing phases during which the speed of the aircraft is low and the incidence high, ie close to stall. As for the slip, it must remain well controlled. Aircraft are equipped with incidence and wander sensors to measure these parameters. In practice, the same probe can be used either to measure the incidence or to measure the slip according to its location on the skin of the aircraft. This type of probe locally measures the direction of air relative to the skin of the aircraft. This is called local incidence. In the following description, the destination of the probe will not be distinguished. It is understood that the invention applies both to incidence probes and to skid probes. This type of probe will be called hereafter: incidence probe. There are two main families of incidence probes. The first family is formed by so-called mobile probes. They include a movable element orienting in the direction of the air flow. This movable element is generally a pallet movable in rotation about an axis perpendicular to the skin of the aircraft. The incidence measurement is carried out in measuring the angular position of the movable element around its axis of rotation. These probes exhibit friction between the movable element and the skin of the aircraft. This friction disturbs the measurement all the more as the speed of the air flow is low. In fact at low speed, the aerodynamic forces exerted on the mobile element are weak and have difficulty in overcoming friction. In addition, it is necessary to seal the probe at the junction between the movable pallet and the skin of the aircraft. The second family is formed by so-called fixed probes. They have a fixed body protruding from the skin of the aircraft. The fixed body is aerodynamically profiled and has several pressure taps. The pressure measurements made by means of the pressure taps make it possible to calculate the incidence of the air flow relative to the fixed body. These probes do not exhibit friction but are vulnerable at the level of the pressure taps which can become clogged with water or during the passage of the aircraft through dust clouds, making pressure measurements impossible and therefore the determination of the impact. Certain mobile probes may include pressure taps in order to improve the orientation of the mobile element in the direction of the air flow. They then combine the drawbacks of the two families of probes previously described. The invention aims to overcome the drawbacks of the two families of probes by proposing a new principle of fixed incidence probe, therefore without friction, and without pressure measurement. To this end, the subject of the invention is an incidence probe, intended to measure the incidence of an air flow circulating outside a skin, characterized in that it comprises a body located at the outside of the skin and means for measuring a force exerted by the air flow on the body.
L'invention sera mieux comprise et d'autres avantages apparaîtront à la lecture de la description détaillée de deux modes de réalisation donnés à titre d'exemples, description illustrée par le dessin joint dans lequel : La figure 1 représente un corps formant une partie sensible à un flux d'air d'une sonde d'incidence ; les figures 2a et 2b représentent un premier mode de réalisation de l'invention dans lequel des moyens de mesure d'un effort exercé par le flux d'air sur le corps comportent des jauges de déformation ; les figures 3a et 3b représentent un second mode de réalisation de l'invention dans lequel les moyens de mesure d'un effort exercé par le flux d'air sur le corps comportent des électrodes formant des capacités ; la figure 4 représente la sonde d'incidence représentée sur la figure 1 à laquelle on a ajouté des prises de pression pariétales. La sonde d'incidence représentée sur la figure 1 comporte un corps 1 situé à l'extérieur d'une peau 2 par exemple celle d'un aéronef. Le corps 1 forme la partie sensible de la sonde d'incidence. La direction d'un flux d'air, matérialisée par la flèche 3, que l'on souhaite déterminer au moyen de la sonde d'incidence est parallèle à la peau 2. Dans sa configuration la plus simple, le corps 1 est à symétrie de révolution autour d'un axe 4 sensiblement perpendiculaire à la surface de la peau 2. Sur la figure 1 , le corps 1 est un cylindre d'axe 4. Pour simplifier la description, le cylindre portera également le repère 1. Le cylindre 1 est soumis à des forces aérodynamiques crées par le flux d'air. En raison de la symétrie de révolution du cylindre 1 , la résultante de ces forces aérodynamiques est la traînée 5 dont la direction est identique à la direction 3 du flux d'air. La sonde d'incidence comporte des moyens de mesure d'un effort exercé par le flux d'air sur le corps 1 , autrement dit, des moyens de mesure de la traînée 5. En mesurant la direction de la traînée 5 on obtient directement l'incidence du flux d'air par rapport à la sonde du fait de d'identité de direction entre celle du flux d'air et celle de la traînée 5. La traînée 5 est équilibrée par des forces de réaction d'une plaque 6 assurant la fixation du corps 1 à la peau 2. Avantageusement, les moyens de mesure d'un effort comportent des moyens élastiques maintenant le corps 1 solidaire de la peau 2, et des moyens de mesure de position relative du corps 1 par rapport à la peau 2. Une plaque 6 forme les moyens élastiques maintenant le corps 1 solidaire de la peau 2. Plus précisément, en donnant à la plaque 6 une certaine élasticité, la modification de la position relative du corps 1 par rapport à la peau 2 est représentative de la traînée 5 et donc de la direction du flux d'air. En mesurant cette modification on peut donc déterminer l'incidence du flux d'air par rapport à la sonde. Il est bien entendu possible de donner au corps 1 une toute autre forme que celle représentée sur la figure 1. Le corps 1 peut par exemple former le corps d'une autre sonde montée sur un aéronef, comme par exemple un tube de Pitot ou une sonde de température totale. Du fait de l'absence de symétrie de révolution de cette sonde, la résultante des forces aérodynamiques exercées par le flux d'air sur le corps 1 peut avoir une direction différente de celle du flux d'air. La résultante des forces aérodynamiques est alors la somme de la traînée et de la portance. Ces deux forces sont exercées par le flux d'air. Il est néanmoins possible de définir une relation univoque entre la résultante des forces aérodynamiques et l'incidence du flux d'air. Cette relation est par exemple définie de façon empirique par des essais en soufflerie. Cette relation prend essentiellement en compte la vitesse et l'incidence du flux d'air. On peut, comme précédemment, déterminer l'incidence du flux d'air par rapport à la sonde à partir d'une mesure de l'effort exercé par le flux d'air sur le corps 1. Avantageusement, la sonde d'incidence comporte un contrepoids 7 fixé au corps 1 et disposé de telle sorte que le centre de gravité d'un ensemble formé par le corps 1 et le contrepoids 7 est sensiblement situé au niveau de la surface de la peau 2. Le contrepoids 7 est visible sur la figure 2a. La modification de la position relative du corps 1 par rapport à la peau 2 se fait alors essentiellement par une rotation autour du centre de gravité de l'ensemble. La position du centre de gravité de l'ensemble au niveau de la peau 2 permet de limiter la sensibilité de la mesure de position relative du corps par rapport à la peau 2 à des accélérations de l'aéronef notamment celles dont la direction est perpendiculaire à l'axe 4 du corps 1. Avantageusement, les moyens de mesure d'un effort sont répartis de façons symétriques autour de l'axe 4 lorsque le corps 1 est cylindrique ou de façon plus générale autour d'un axe d'inertie du corps 1 , axe perpendiculaire à la surface de la peau 2. Cette caractéristique associée à une position du centre de gravité de l'ensemble au niveau de la peau 2 permet d'obtenir deux fois la même valeur, au signe près, pour chaque moyen de mesure et ainsi améliorer la sensibilité et la fiabilité de la sonde d'incidence. En effet, la mesure d'un déplacement en rotation réalisée par des moyens de mesure disposés de façon symétrique par rapport au point autour duquel la rotation s'effectue donne des résultats opposés. Les figures 2a et 2b représentent un premier mode de réalisation des moyens de mesure de position. Plus précisément, les moyens de mesure de position comportent au moins une jauge de déformation 10a fixée sur les moyens élastiques 6 et mesurant une déformation des moyens élastiques 6. La figure 2a représente le premier mode de réalisation sans l'action du flux d'air. Les moyens élastiques 6 sont fixés d'une part sur la peau 2 et d'autre part sur le corps 1. Les moyens élastiques 6 ont par exemple la forme d'une rondelle d'axe 4. La jauge de déformation 10a est fixée sur les moyens élastiques 6 du côté intérieur de la peau 6. La mesure de la déformation des moyens élastiques 6 est réalisée en mesurant la différence de valeur de résistance de la jauge de déformation 10a entre une position de référence comme par exemple celle représentée sur la figure 2a et une position où le corps 1 est soumis à l'action du flux d'air 3 comme représenté sur la figure 2b. Avantageusement, les moyens de mesure de position comportent plusieurs jauges de déformation réparties de façons symétriques autour de l'axe 4. Sur les figures 2a et 2b deux jauges ont été représentées et elles portent les repères 10a et 10b. Les variations de résistances de deux jauges de déformation 10a et 10b disposées de façon symétrique sont opposées. En plaçant ces deux jauges de déformation 10a et 10b dans deux branches opposées d'un pont de Wheatstone alimenté par une tension continue la tension mesurée en sortie du pont est représentative de la modification de position du corps 1 avec un gain double de celui obtenu avec une seule jauge de déformation 10a. La figure 2b représente la déformation des moyens élastiques 6 dans une direction portée par le plan de la figure 2b ainsi que les deux jauges de déformation 10a et 10b disposées dans ce même plan. Pour obtenir la véritable incidence du flux d'air, on dispose au moins une autre jauge de déformation, et préférentiellement deux, dans un pian distinct de celui des deux premières jauges de déformation 10a et 10b, par exemple perpendiculaire à celui de la figure 2b. Les déformations mesurées par les jauges de déformation disposées dans des plans orthogonaux permettent de reconstituer l'incidence locale du flux d'air 3 dans un repère orthogonal lié à la peau 2. Les figures 3a et 3b représentent un second mode de réalisation des moyens de mesure de position. Plus précisément, les moyens de mesure de position comportent une première électrode 11 solidaire du corps 1 et au moins une seconde électrode 12a solidaire de la peau 2. Les deux électrodes 1 1 et 12a forment une capacité variant en fonction de la modification de la position relative du corps 1 par rapport à la peau 2. La figure 3a représente le second mode de réalisation sans l'action du flux d'air. Les moyens élastiques 6 sont fixés d'une part sur la peau 2 et d'autre part sur le corps 1 par exemple par l'intermédiaire de la première électrode 11. Les moyens élastiques 6 ont par exemple comme sur les figures 2a et 2b la forme d'une rondelle d'axe 4. La seconde électrode 12a est par exemple fixée à l'intérieur d'un boîtier 13 fixé à la peau 2. Comme dans le premier mode de réalisation, les moyens de mesure de position comportent avantageusement, plusieurs secondes électrodes réparties de façons symétriques autour de l'axe 4. Sur les figures 3a et 3b deux secondes électrodes ont été représentées et elles portent les repères 12a et 12b. Les valeurs de capacités entre d'une part les électrodes 11 et 12a et entre d'autre part les électrodes 11 et 12b varient de façon opposée. Ceci permet, comme dans le premier mode de réalisation, d'augmenter le gain dans la mesure de position. Il est bien entendu possible de disposer au moins une autre électrode solidaire de la peau 2, et préférentiellement deux, en regard de l'électrode 11 , dans un plan distinct de celui des deux électrodes12a et 12b, par exemple perpendiculaire à celui de la figure 3b afin de reconstituer l'incidence locale du flux d'air 3 dans un repère orthogonal lié à la peau 2. L'invention peut être mise en oeuvre avec d'autres moyens de mesure de position, comme par exemple des moyens optiques basés sur un effet de moiré. Plus précisément, la sonde d'incidence comporte deux grilles identiques, transparentes et présentant des lignes opaques. L'une de ces grilles est solidaire du corps 1 et l'autre de la peau 2. les deux grilles sont placées en regard l'une de l'autre. On fait passer un rayon lumineux au travers des deux grilles et on analyse l'intensité du rayon en aval des deux grilles. Lorsque les lignes opaques des deux grilles sont en regard, l'intensité mesurée en aval des grilles est maximale et lorsque les lignes opaques des deux grilles sont en opposition l'intensité est minimale. La mesure de l'intensité permet de déterminer la position relative du corps 1 par rapport à la peau 2 de l'aéronef. Il est possible de disposer, solidaire de la peau 2 à la fois des moyens émettant le rayon lumineux et des moyens d'analyse de son intensité en aval des deux grilles, en disposant un miroir solidaire du corps 1 sur le chemin optique du rayon lumineux. Avantageusement, le corps 1 comporte des moyens de réchauffage afin d'éviter la formation de givre sur le corps 1. La formation de givre risque de se produire lors de vols de l'aéronef en haute altitude. Les moyens de réchauffage comportent par exemple un fil chauffant disposé à l'intérieur du corps 1 et alimenté par une source de tension électrique, ou bien encore des moyens permettant la circulation d'un fluide caloporteur à l'intérieur du corps 1. Avantageusement, la sonde comporte des moyens pour déterminer la direction et l'intensité de l'effort 5 exercé par le flux d'air sur le corps 1. En effet, la direction de l'effort donne l'incidence locale du flux d'air par rapport à la sonde et l'intensité de l'effort permet de déterminer la vitesse du flux d'air. Plus précisément, l'effort est proportionnel à la densité de l'air et au carré de la vitesse du flux d'air. Le coefficient de proportionnalité est déterminé par la géométrie du corps 1. La densité de l'air peut être connue par des moyens extérieurs à la sonde comme par exemple au moyen d'un altimètre. La figure 4 représente une sonde d'incidence comportant avantageusement au moins une prise de pression 20 ou 21 disposée sur la peau 2 à proximité du corps 1 et plus précisément sur la plaque 6. Une telle prise de pression 20 ou 21 permet de déterminer la pression statique Ps du flux d'air entourant la sonde. On définit la position de la prise de pression 20 ou 21 de façon à ne pas perturber la déformation de la plaque 6 lorsque le corps 1 est soumis à un effort 5. A cet effet, la prise de pression est en général disposée à la périphérie de la plaque 6. Une telle sonde réalisant dans un même équipement les mesures d'incidence et de pression statique permet d'obtenir, associée à une autre sonde multifonction mesurant la pression et la température totale, telle que celle décrite dans la demande de brevet FR 2 823 846, l'ensemble des paramètres aérodynamiques de l'aéronef, à l'exception du dérapage. Ces paramètres aérodynamiques sont généralement altérés si le dérapage n'est pas nul. Un système comprenant une sonde multifonction mesurant la pression et la température totale associée à 2 sondes, conforme à la présente invention, mesurant l'incidence et la pression statique, ces 2 dernières sondes étant situées symétriquement par rapport au plan de symétrie vertical de l'avion (coté droit et coté gauche) permet de calculer le dérapage et de s'affranchir de son influence. La demande de brevet FR 2 817 044 montre comment à partir de 2 mesures d'incidence locale on peut calculer les incidence et dérapage vrais de l'avion (paramètres infini amont), et ensuite effectuer toutes les corrections voulues sur les mesures de pressions en fonction de l'incidence et du dérapage. Avantageusement, la sonde d'incidence comporte deux prises de pression 20 et 21 disposées de façon symétrique par rapport à un axe 22 tangent à la peau 2, l'axe tangent 22 étant concourant de l'axe 4. La sonde d'incidence comporte en outre des moyens pour mélanger de façon pneumatique l'air prélevé par les deux prises de pression 20 et 21. La pression statique Ps est alors déterminée à partir du mélange pneumatique. Plus précisément, l'axe tangent 22 est matérialisé sur la sonde d'incidence, par exemple au moyen d'un marquage. Lors du montage de la sonde d'incidence sur l'aéronef, la sonde est orientée autour de son axe 4 de telle sorte que l'axe 22 coïncide avec la direction du flux d'air entourant la sonde d'incidence lorsque l'incidence de l'aéronef est nulle. De cette façon, si la présence du corps 1 modifie légèrement les valeurs des pressions au niveau des deux prises de pression 20 et 21 , augmentant la pression sur l'une et la diminuant sur l'autre, le mélange pneumatique des deux pressions réduit cette influence. En tout état de cause, même si l'on ne dispose qu'une seule prise de pression sur la plaque 6, on peut toujours calculer si nécessaire une valeur corrigée de la pression statique Ps, à partir de la pression dynamique, que l'on sait déduire de la mesure de la force 5 appliquée au corps 1. Le corps 1 peut être rigide, c'est à dire très peu déformable par rapport aux moyens de mesure d'un effort décrits à l'aide des figures 2a, 2b, 3a et 3b. A titre d'alternative, le corps 1 peut être déformable sous l'action du flux d'air. Dans ce cas, les moyens de mesure d'un effort 5 exercé par le flux d'air sur le corps 1 comportent des moyens de mesure de la déformation du corps 1 lui même. Ces moyens de mesure de déformation comportent par exemple au moins une jauge de déformation fixée sur le corps 1 et mesurant sa flexion sous l'effet du flux d'air. Ici encore il est possible de disposer sur le corps 1 plusieurs jauges de déformation autour du corps pour augmenter le gain de la mesure et pour reconstituer l'incidence locale. The invention will be better understood and other advantages will appear on reading the detailed description of two embodiments given by way of examples, description illustrated by the attached drawing in which: FIG. 1 represents a body forming a sensitive part to an air flow from an incidence probe; Figures 2a and 2b show a first embodiment of the invention in which means for measuring a force exerted by the air flow on the body include strain gauges; Figures 3a and 3b show a second embodiment of the invention in which the means for measuring a force exerted by the air flow on the body include electrodes forming capacitors; Figure 4 shows the incidence probe shown in Figure 1 to which were added parietal pressure taps. The incidence probe shown in FIG. 1 comprises a body 1 situated outside a skin 2, for example that of an aircraft. The body 1 forms the sensitive part of the incidence probe. The direction of an air flow, materialized by arrow 3, which one wishes to determine by means of the incidence probe is parallel to the skin 2. In its simplest configuration, the body 1 is symmetrical of revolution around an axis 4 substantially perpendicular to the surface of the skin 2. In FIG. 1, the body 1 is a cylinder of axis 4. To simplify the description, the cylinder will also bear the reference 1. The cylinder 1 is subjected to aerodynamic forces created by the air flow. Due to the symmetry of revolution of the cylinder 1, the result of these aerodynamic forces is the drag 5 whose direction is identical to the direction 3 of the air flow. The angle of attack sensor comprises means for measuring a force exerted by the air flow on the body 1, in other words, means for measuring the drag 5. By measuring the direction of the drag 5, one obtains directly l incidence of the air flow relative to the probe due to the identity of direction between that of the air flow and that of the drag 5. The drag 5 is balanced by the reaction forces of a plate 6 ensuring the attachment of the body 1 to the skin 2. Advantageously, the means for measuring a force comprise elastic means holding the body 1 secured to the skin 2, and means for measuring the relative position of the body 1 relative to the skin 2. A plate 6 forms the elastic means holding the body 1 integral with the skin 2. More precisely, by giving the plate 6 a certain elasticity, the modification of the relative position of the body 1 relative to the skin 2 is representative of drag 5 and therefore direction of the air flow. By measuring this modification, it is therefore possible to determine the incidence of the air flow relative to the probe. It is of course possible to give the body 1 a completely different shape than that shown in FIG. 1. The body 1 can for example form the body of another probe mounted on an aircraft, such as for example a Pitot tube or a total temperature probe. Due to the absence of symmetry of revolution of this probe, the result of the aerodynamic forces exerted by the air flow on the body 1 may have a direction different from that of the air flow. The result of the aerodynamic forces is then the sum of the drag and the lift. These two forces are exerted by the air flow. It is nevertheless possible to define a unique relationship between the result of aerodynamic forces and the incidence of air flow. This relationship is for example empirically defined by wind tunnel tests. This relationship essentially takes into account the speed and incidence of the air flow. It is possible, as previously, to determine the incidence of the air flow relative to the probe from a measurement of the force exerted by the air flow on the body 1. Advantageously, the incidence probe comprises a counterweight 7 fixed to the body 1 and arranged so that the center of gravity of an assembly formed by the body 1 and the counterweight 7 is substantially located at the surface of the skin 2. The counterweight 7 is visible on the Figure 2a. The modification of the relative position of the body 1 relative to the skin 2 is then essentially done by a rotation around the center of gravity of the assembly. The position of the center of gravity of the assembly at the level of the skin 2 makes it possible to limit the sensitivity of the measurement of the relative position of the body with respect to the skin 2 to accelerations of the aircraft, in particular those whose direction is perpendicular to the axis 4 of the body 1. Advantageously, the means for measuring a force are distributed symmetrically around the axis 4 when the body 1 is cylindrical or more generally around an axis of inertia of the body 1, axis perpendicular to the surface of the skin 2. This characteristic associated with a position of the center of gravity of the assembly at the level of the skin 2 makes it possible to obtain twice the same value, except for the sign, for each means of measure and thus improve the sensitivity and reliability of the incidence sensor. Indeed, the measurement of a rotational displacement carried out by measuring means arranged symmetrically with respect to the point around which the rotation takes place gives opposite results. Figures 2a and 2b show a first embodiment of the position measuring means. More specifically, the position measuring means comprise at least one deformation gauge 10a fixed on the elastic means 6 and measuring a deformation of the elastic means 6. FIG. 2a shows the first embodiment without the action of the air flow . The elastic means 6 are fixed on the one hand to the skin 2 and on the other hand to the body 1. The elastic means 6 have for example the shape of a washer with an axis 4. The strain gauge 10a is fixed on the elastic means 6 on the inner side of the skin 6. The measurement of the deformation of the elastic means 6 is carried out by measuring the difference in resistance value of the deformation gauge 10a between a reference position such as that shown in the figure 2a and a position where the body 1 is subjected to the action of the air flow 3 as shown in FIG. 2b. Advantageously, the position measurement means comprise several strain gauges distributed symmetrically around the axis 4. In FIGS. 2a and 2b two gauges have been shown and they bear the marks 10a and 10b. The resistance variations of two strain gauges 10a and 10b arranged symmetrically are opposite. By placing these two strain gauges 10a and 10b in two opposite branches of a Wheatstone bridge supplied by a DC voltage, the voltage measured at the output of the bridge is representative of the change in position of the body 1 with a gain twice that obtained with a single strain gauge 10a. Figure 2b shows the deformation of the elastic means 6 in a direction carried by the plane of Figure 2b and the two deformation gauges 10a and 10b arranged in the same plane. To obtain the true incidence of the air flow, there is at least one other strain gauge, and preferably two, in a plane different from that of the first two strain gauges 10a and 10b, for example perpendicular to that of FIG. 2b . The deformations measured by the strain gauges arranged in orthogonal planes make it possible to reconstitute the local incidence of the air flow 3 in an orthogonal coordinate system linked to the skin 2. FIGS. 3a and 3b represent a second embodiment of the position measurement means. More specifically, the position measuring means comprise a first electrode 11 secured to the body 1 and at least a second electrode 12a secured to the skin 2. The two electrodes 11 and 12a form a capacity varying according to the modification of the position relative of the body 1 with respect to the skin 2. FIG. 3a represents the second embodiment without the action of the air flow. The elastic means 6 are fixed on the one hand to the skin 2 and on the other hand to the body 1 for example by means of the first electrode 11. The elastic means 6 have for example as in FIGS. 2a and 2b the shape of an axis washer 4. The second electrode 12a is for example fixed inside a housing 13 fixed to the skin 2. As in the first embodiment, the position measuring means advantageously include, several second electrodes distributed symmetrically around the axis 4. In FIGS. 3a and 3b two second electrodes have been shown and they bear the marks 12a and 12b. The capacitance values between on the one hand the electrodes 11 and 12a and between on the other hand the electrodes 11 and 12b vary in opposite fashion. This allows, as in the first embodiment, to increase the gain in the position measurement. It is of course possible to have at least one other electrode secured to the skin 2, and preferably two, facing the electrode 11, in a plane distinct from that of the two electrodes 12a and 12b, for example perpendicular to that of the figure 3b in order to reconstruct the local incidence of the air flow 3 in an orthogonal coordinate system linked to the skin 2. The invention can be implemented with other position measurement means, such as for example optical means based on a moire effect. More specifically, the incidence probe comprises two identical grids, transparent and having opaque lines. One of these grids is integral with the body 1 and the other with the skin 2. the two grids are placed opposite one another. A light ray is passed through the two grids and the intensity of the ray downstream of the two grids is analyzed. When the opaque lines of the two grids are opposite, the intensity measured downstream of the grids is maximum and when the opaque lines of the two grids are in opposition the intensity is minimal. The measurement of the intensity makes it possible to determine the relative position of the body 1 relative to the skin 2 of the aircraft. It is possible to have, secured to the skin 2, both means emitting the light ray and means for analyzing its intensity downstream of the two grids, by placing a mirror secured to the body 1 on the optical path of the light ray. . Advantageously, the body 1 comprises reheating means in order to avoid the formation of frost on the body 1. The formation of frost is likely to occur during flights of the aircraft at high altitude. The heating means comprise for example a heating wire placed inside the body 1 and supplied by a source of electric voltage, or alternatively means allowing the circulation of a heat-transfer fluid inside the body 1. Advantageously, the probe includes means for determining the direction and intensity of the force 5 exerted by the air flow on the body 1. Indeed, the direction of the force gives the local incidence of the air flow by ratio to the probe and the intensity of the effort makes it possible to determine the speed of the air flow. More precisely, the force is proportional to the density of the air and to the square of the speed of the air flow. The coefficient of proportionality is determined by the geometry of the body 1. The density of the air can be known by means external to the probe such as for example by means of an altimeter. FIG. 4 represents an incidence probe advantageously comprising at least one pressure tap 20 or 21 placed on the skin 2 near the body 1 and more precisely on the plate 6. Such a pressure tap 20 or 21 makes it possible to determine the static pressure Ps of the air flow surrounding the probe. The position of the pressure tap 20 or 21 is defined so as not to disturb the deformation of the plate 6 when the body 1 is subjected to a force 5. For this purpose, the pressure tap is generally disposed at the periphery of plate 6. Such a probe carrying out in the same equipment the incidence and static pressure measurements makes it possible to obtain, associated with another multifunction probe measuring the pressure and the total temperature, such as that described in the patent application. FR 2 823 846, all aerodynamic parameters of the aircraft, with the exception of sideslip. These aerodynamic parameters are generally altered if the wander is not zero. A system comprising a multifunction probe measuring the pressure and the total temperature associated with 2 probes, in accordance with the present invention, measuring the incidence and the static pressure, the latter 2 probes being located symmetrically with respect to the vertical plane of symmetry of the airplane (right side and left side) allows to calculate the skid and to get rid of its influence. Patent application FR 2 817 044 shows how, from 2 local incidence measurements, it is possible to calculate the true incidence and wander of the aircraft (upstream infinite parameters), and then to carry out all the desired corrections on the pressure measurements in depending on the incidence and wander. Advantageously, the incidence probe comprises two pressure taps 20 and 21 arranged symmetrically with respect to an axis 22 tangent to the skin 2, the tangent axis 22 being concurrent with the axis 4. The incidence probe comprises further means for pneumatically mixing the air taken off by the two pressure taps 20 and 21. The static pressure Ps is then determined from the pneumatic mixture. More specifically, the tangent axis 22 is materialized on the incidence probe, for example by means of a marking. During the mounting of the incidence probe on the aircraft, the probe is oriented around its axis 4 so that the axis 22 coincides with the direction of the air flow surrounding the incidence probe when the incidence of the aircraft is void. In this way, if the presence of the body 1 slightly modifies the values of the pressures at the level of the two pressure taps 20 and 21, increasing the pressure on one and decreasing it on the other, the pneumatic mixture of the two pressures reduces this affecting. In any event, even if there is only one pressure tap on the plate 6, it is still possible to calculate if necessary a corrected value of the static pressure Ps, from the dynamic pressure, that the it is known to deduce from the measurement of the force 5 applied to the body 1. The body 1 can be rigid, that is to say very little deformable with respect to the means for measuring a force described with the aid of FIGS. 2a, 2b , 3a and 3b. Alternatively, the body 1 can be deformable under the action of the air flow. In this case, the means for measuring a force 5 exerted by the air flow on the body 1 comprise means for measuring the deformation of the body 1 itself. These deformation measuring means comprise for example at least one deformation gauge fixed to the body 1 and measuring its bending under the effect of the air flow. Here again it is possible to arrange on the body 1 several strain gauges around the body to increase the gain of the measurement and to reconstruct the local incidence.

Claims

REVENDICATIONS
1. Sonde d'incidence, destinée à mesurer l'incidence d'un flux d'air circulant à l'extérieur d'une peau (2), caractérisée en ce qu'elle comporte un corps (1 ) situé à l'extérieur de la peau (2) et des moyens de mesure d'un effort (5) exercé par le flux d'air sur le corps (1 ).1. Incidence probe, intended to measure the incidence of an air flow circulating outside a skin (2), characterized in that it comprises a body (1) located outside skin (2) and means for measuring a force (5) exerted by the air flow on the body (1).
2. Sonde d'incidence seion la revendication 1 , caractérisée en ce que les moyens de mesure d'un effort comportent des moyens élastiques (6) maintenant le corps (1) solidaire de la peau (2), et des moyens de mesure de position relative du corps (1 ) par rapport à la peau (2).2. incidence sensor according to claim 1, characterized in that the means for measuring a force comprise elastic means (6) holding the body (1) integral with the skin (2), and means for measuring relative position of the body (1) relative to the skin (2).
3. Sonde d'incidence selon l'une des revendications précédentes, caractérisée en ce que le corps (1 ) est à symétrie de révolution autour d'un axe (4) sensiblement perpendiculaire à la surface de la peau (2). 3. Incidence probe according to one of the preceding claims, characterized in that the body (1) is rotationally symmetrical about an axis (4) substantially perpendicular to the surface of the skin (2).
4. Sonde d'incidence selon l'une des revendications précédentes, caractérisée en ce qu'elle comporte un contrepoids (7) fixé au corps (1 ) et disposé de telle sorte que le centre de gravité d'un ensemble formé par le corps (1 ) et le contrepoids (7) est sensiblement situé au niveau de la surface de la peau (2).4. Incidence probe according to one of the preceding claims, characterized in that it comprises a counterweight (7) fixed to the body (1) and arranged so that the center of gravity of an assembly formed by the body (1) and the counterweight (7) is substantially located at the surface of the skin (2).
5. Sonde d'incidence selon l'une des revendications précédentes, caractérisée en ce que le corps (1) comporte un axe d'inertie (4) perpendiculaire à la surface de la peau (2), et en ce que les moyens de mesure d'un effort (5) sont répartis de façons symétriques autour de l'axe d'inertie (4).5. Incidence probe according to one of the preceding claims, characterized in that the body (1) has an axis of inertia (4) perpendicular to the surface of the skin (2), and in that the means for measurement of a force (5) are distributed symmetrically around the axis of inertia (4).
6. Sonde d'incidence selon l'une quelconque des revendications 2 à 5, caractérisée en ce que les moyens de mesure de position comportent au moins une jauge de déformation (10a, 10b) fixée sur les moyens élastiques (6) et mesurant une déformation des moyens élastiques (6).6. Incidence probe according to any one of claims 2 to 5, characterized in that the position measuring means comprise at least one strain gauge (10a, 10b) fixed on the elastic means (6) and measuring a deformation of the elastic means (6).
7. Sonde d'incidence selon l'une quelconque des revendications 2 à 5, caractérisée en ce que les moyens de mesure comportent une première électrode (11 ) solidaire du corps (1 ) et au moins une seconde électrode (12a, 12b) solidaire de la peau (2), les deux électrodes (11 , 12a, 12b) formant une capacité variant en fonction de la modification de la position relative du corps (1 ) par rapport à la peau (2). 7. Incidence probe according to any one of claims 2 to 5, characterized in that the measuring means comprise a first electrode (11) secured to the body (1) and at least a second electrode (12a, 12b) integral with the skin (2), the two electrodes (11, 12a, 12b) forming a capacity varying as a function of the modification of the relative position of the body (1) relative to the skin (2).
8. Sonde d'incidence selon l'une des revendications précédentes, caractérisée en ce que le corps (1 ) comporte des moyens de réchauffage.8. Incidence probe according to one of the preceding claims, characterized in that the body (1) comprises heating means.
9. Sonde d'incidence selon l'une des revendications précédentes, caractérisée en ce qu'elle comporte des moyens pour déterminer la direction d'un effort (5) exercé par le flux d'air sur le corps (1).9. Incidence probe according to one of the preceding claims, characterized in that it comprises means for determining the direction of a force (5) exerted by the air flow on the body (1).
10. Sonde d'incidence selon l'une des revendications précédentes, caractérisée en ce qu'elle comporte des moyens pour déterminer l'intensité d'un effort (5) exercé par le flux d'air sur le corps (1 ).10. Incidence probe according to one of the preceding claims, characterized in that it comprises means for determining the intensity of a force (5) exerted by the air flow on the body (1).
11. Sonde d'incidence selon l'une des revendications précédentes, caractérisée en ce qu'elle comporte au moins une prise de pression (20, 21) disposée sur la peau (2) à proximité du corps (1). 11. Incidence probe according to one of the preceding claims, characterized in that it comprises at least one pressure tap (20, 21) disposed on the skin (2) near the body (1).
12. Sonde d'incidence selon revendication 11 , caractérisée en ce qu'elle comporte deux prises de pression (20, 21) disposées de façon symétrique par rapport à un axe tangent (22) à la peau (2), l'axe tangent (22) étant concourant d'un axe (4) de symétrie du corps (1 ), et en ce que la sonde d'incidence comporte des moyens pour mélanger de façon pneumatique l'air prélevé par les deux prises de pression (20, 21 ).12. Incidence probe according to claim 11, characterized in that it comprises two pressure taps (20, 21) arranged symmetrically with respect to a tangent axis (22) to the skin (2), the tangent axis (22) being concurrent with an axis (4) of symmetry of the body (1), and in that the incidence probe comprises means for pneumatically mixing the air taken up by the two pressure taps (20, 21).
13. Sonde d'incidence selon l'une des revendications précédentes, caractérisée en ce que le corps (1) est rigide. 13. Incidence probe according to one of the preceding claims, characterized in that the body (1) is rigid.
14. Sonde d'incidence selon l'une quelconque des revendications14. Incidence probe according to any one of claims
1 à 12, caractérisée en ce que le corps (1 ) est déformable sous l'action du flux d'air et en ce que les moyens de mesure d'un effort (5) exercé par le flux d'air sur le corps (1) comportent des moyens de mesure de la déformation du corps (1 ). 1 to 12, characterized in that the body (1) is deformable under the action of the air flow and in that the means for measuring a force (5) exerted by the air flow on the body ( 1) include means for measuring the deformation of the body (1).
EP04818835A 2003-11-18 2004-11-18 Attack angle probe Withdrawn EP1685371A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR0313492A FR2862383B1 (en) 2003-11-18 2003-11-18 IMPACT PROBE
PCT/EP2004/053007 WO2005050154A1 (en) 2003-11-18 2004-11-18 Attack angle probe

Publications (1)

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EP1685371A1 true EP1685371A1 (en) 2006-08-02

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Application Number Title Priority Date Filing Date
EP04818835A Withdrawn EP1685371A1 (en) 2003-11-18 2004-11-18 Attack angle probe

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US (1) US20070119231A1 (en)
EP (1) EP1685371A1 (en)
FR (1) FR2862383B1 (en)
WO (1) WO2005050154A1 (en)

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EP2623993A1 (en) * 2012-02-01 2013-08-07 IRDAM Institut de Recherches et Développements Aérologiques Marketing SA Wind speed and direction measuring device
WO2014132138A2 (en) * 2013-02-07 2014-09-04 King Abdullah University Of Science And Technology Method and sensors for estimating and predicting airflow around air vehicles
FR3008073B1 (en) * 2013-07-04 2015-08-07 Thales Sa AIRCRAFT COMPRISING A MEASURING PROBE AND METHOD FOR DETERMINING FLIGHT PARAMETERS OF SUCH AN AIRCRAFT
EP3598143B1 (en) * 2018-07-18 2021-10-27 Jean-Daniel Carrard Device for measuring the speed of movement of a fluid

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US3108473A (en) * 1960-07-25 1963-10-29 Giannini Controls Corp Fluid stream direction indicator
JP2913005B2 (en) * 1992-04-06 1999-06-28 科学技術庁航空宇宙技術研究所長 Flight velocity vector detection system using a truncated polygonal pitot tube probe and a truncated polygonal pitot tube probe
JP2694263B2 (en) * 1994-08-23 1997-12-24 科学技術庁航空宇宙技術研究所長 Three-dimensional airflow generator, flight control system verification method for aircraft using the device, and flight motion simulator
JP2952397B2 (en) * 1994-08-23 1999-09-27 科学技術庁航空宇宙技術研究所長 Active air control aircraft using air speed vector measurement device
FR2793022B1 (en) * 1999-04-30 2001-07-13 Sextant Avionique FIXED MULTIFUNCTION PROBE FOR AIRCRAFT
FR2802636B1 (en) * 1999-12-17 2002-03-22 Thomson Csf Sextant MULTIFUNCTIONAL PROBE FOR AIRCRAFT
US6526821B1 (en) * 2001-07-18 2003-03-04 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Airfoil shaped flow angle probe
FR2833347B1 (en) * 2001-12-11 2004-02-27 Thales Sa MULTIFUNCTIONAL PROBE FOR AIRCRAFT
FR2859787B1 (en) * 2003-09-16 2006-01-20 Thales Sa DEVICE AND METHOD FOR DETERMINING THE TOTAL TEMPERATURE FOR AN AIRCRAFT

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Also Published As

Publication number Publication date
US20070119231A1 (en) 2007-05-31
WO2005050154A1 (en) 2005-06-02
FR2862383B1 (en) 2006-02-17
FR2862383A1 (en) 2005-05-20

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