A towing assembly comprising a towing and handling device intended to tow a faired elongate element, the towing device comprises a winch allowing the faired elongate element to be wound in and paid out through a guide device that allows the elongate element to be guided, the guide device comprising
A towing assembly comprising a towing and handling device intended to tow a faired elongate element, the towing device comprises a winch allowing the faired elongate element to be wound in and paid out through a guide device that allows the elongate element to be guided, the guide device comprising a first groove the bottom of which is formed by the bottom of the groove of a pulley, the first groove being delimited by a first surface having a profile that is concave in a radial plane of the pulley, the width of the first groove and the curvature of the profile of the first curved surface in the radial plane being determined in such a way as to allow the fairing element, under the effect of the rotation of the fairing element about the axis of the elongate element under the effect of the traction of the elongate element with respect to the guide device along the longitudinal axis thereof, to flip from a turned-over position in which the fairing element is oriented with its trailing edge toward the bottom of the first groove into an acceptable position in which it is oriented with the leading edge toward the bottom of the first groove.
대표청구항▼
1. A towing assembly comprising an elongate element faired by means of a fairing comprising a plurality of fairing elements, the fairing elements comprising a canal intended to accept the elongate object and being profiled in such a way as to reduce the hydrodynamic drag of the elongate object which
1. A towing assembly comprising an elongate element faired by means of a fairing comprising a plurality of fairing elements, the fairing elements comprising a canal intended to accept the elongate object and being profiled in such a way as to reduce the hydrodynamic drag of the elongate object which is at least partially immersed, said fairing elements being pivot-mounted on the elongate element around the longitudinal axis of the canal, the towing assembly further comprising a towing and handling device intended to tow the faired elongate element while the latter is partially immersed, the towing device comprising a winch allowing the faired elongate element to be wound in and paid out through a guide device that allows the elongate element to be guided, wherein the guide device comprises a first groove the bottom of which is formed by the bottom of the groove of a pulley, the first groove being delimited by a first surface having a profile that is concave in a radial plane of the pulley, the width of the first groove and the curvature of the profile of the first curved surface in the radial plane being determined in such a way as to allow the fairing element, under the effect of the rotation of the fairing element about the axis of the elongate element x under the effect of the traction of the elongate element with respect to the guide device along the longitudinal axis thereof, to flip from a turned-over first position in which the fairing element is oriented with its trailing edge toward the bottom of the first groove into a second position in which it is oriented with the leading edge toward the bottom of the first groove. 2. The towing assembly as claimed in claim 1, in which the guide device comprises a first groove the bottom of which is formed by the bottom of the groove of a pulley, the first groove being delimited by a first concave surface of which the cross section a radial plane of the pulley is a first concave curve comprising the bottom coinciding with the bottom of a second, reference, groove delimited by a second curved surface of which the cross section in a radial plane BB is a V-shaped reference curve, the aperture of the V being at least equal to twice a threshold angle αs, and the width of the V lv, measured along a straight line d parallel to the axis of the pulley, is at least equal to a threshold width is, given by: ls=0.7⋆ltdltd=2(LC+E)⋆sin(αs)αs=αi⋆RR-CARwhere αi is a limit angle greater than 45° and less than 90°, where R is the radius of the pulley and where CAR is the maximum distance separating the trailing edge BF of the fairing elements of the fairing from the axis of the elongate element, measured parallel to the chord CO of the fairing elements, where LC is the chord length of the fairing elements and E is the maximum thickness of the fairing elements,in which the first curve is coincident with the second curve at two endpoints of the reference curve, the first curve is at every point comprised between each of the endpoints and the bottom coincident with the second curve or closer to the axis of the pulley (xp) than the second curve along the radius of the pulley in the radial plane BB. 3. The towing assembly as claimed in claim 2, in which the limit angle αi is given by the following formula: αi=π4+12Arctan(Cf)where Cf is the coefficient of friction between the material that forms the exterior part of the tail of the fairing element and the material that forms the surface delimiting the groove of the pulley. 4. The towing assembly as claimed in claim 1, in which the first groove is the groove of the pulley. 5. The towing assembly as claimed in claim 1, in which the concave first curve has a U-shaped profile between the endpoints. 6. The towing assembly as claimed in claim 1, in which the fairing elements comprise a fairing element comprising a nose accepting the elongate element and comprising a leading edge and a tail of streamlined shape extending from the nose and comprising a trailing edge, the cross section of the first surface in the radial plane of the pulley being a first concave curve, the concave first curve being defined in a radial plane of the pulley such that, when the fairing element extends with the leading edge perpendicular to the radial plane, whatever the position of a fairing element in the first groove, when the nose of the fairing element is bearing on the concave first curve and the elongate element is exerting on the fairing element, in the radial plane, a force to press the nose of the fairing element against the pulley, said pressing force Fp comprising a component CP perpendicular to the axis of the pulley and a lateral component CL, the trailing edge of the fairing element is not in contact with the concave first curve or is in contact with a part of the concave first curve that forms, with a straight line dp of the radial plane perpendicular to the axis xa extending from the axis of the elongate element x as far as the trailing edge of the fairing element, an angle Υthat is at least equal to an angle of slip αt wherein the angle of slip is given by the following formula: αt=Arctan(Cf)where Cf is the coefficient of friction between the material that forms the exterior part of the tail of the fairing element and the material that forms the surface delimiting the groove of the pulley. 7. The towing assembly as claimed in claim 1, in which the first curve has a U-shaped profile and has a central zone of width equal to g*lid, where lid is the ideal width and g is comprised between 0.7 and 1, between the endpoints coinciding with the endpoints of the reference curve having a width equal to g*lid, the central zone being delimited by the following two curves: an upper curve having a first radius of curvature R1 radius equal to ½* g*lid passing through the bottom and the center of which is situated on a straight line perpendicular to the axis of the pulley passing through the bottom,a lower curve INF comprising a central portion CENT extending substantially parallel to the axis of the pulley symmetric with respect to a plane perpendicular to the radial plane passing through the bottom and extending, along the axis of the pulley, over a first width equal to g*lid and comprising, on each side of the central portion CENT, lateral portions LAT1 and LAT2 connecting the central portion to the endpoints 133, 134 and having a second radius of curvature R2 equal to ¼*g*lid. 8. The towing assembly as claimed in claim 1, in which the the fairing elements are rigid. 9. The towing assembly as claimed in claim 1, in which the fairing comprises a plurality of fairing portions, each fairing portion comprising a plurality of fairing elements joined together along the axis of the elongate element and articulated to one another, the fairing portions being free to rotate about the axis of the elongate element relative to one another. 10. The towing assembly as claimed in claim 9, in which the fairing portions have respective heights along the axis of the canal, these heights being defined as a function of the angular stiffnesses k of the respective fairing portions, and as a function of the chord length LC of said fairing elements of said respective portions so as to prevent a full twist from forming on said respective portions. 11. The towing assembly as claimed in claim 10, in which the fairing portions have respective heights that are less than a maximum height hmax such that: hmax≤π⋆kFLC2where F is a constant comprised between 250 and 500. 12. The towing assembly as claimed in claim 1, in which at least one fairing element comprises a leading edge and a trailing edge, comprises a bearing edge comprising a first bearing edge that is mitered with respect to the leading edge, the first bearing edge being arranged in such a way that the distance between the leading edge and the bearing edge, measured perpendicular to the leading edge, decreases continuously, along an axis parallel to the leading edge, from a first end of the first bearing edge to a second end of the bearing edge, said fairing element being referred to as a mitered fairing element. 13. The towing assembly as claimed in claim 12, in which the bearing edge is arranged in such a way that the distance between the bearing edge and the leading edge decreases continuously, along an axis parallel to the leading edge, from the first end of the first bearing edge to a first lateral face of the fairing element closer to the second to the first bearing edge than to the first end of the bearing edge. 14. The towing assembly as claimed in claim 12, in which the bearing edge is the trailing edge. 15. The towing assembly as claimed in claim 12, in which the mitered fairing element is sized in such a way as to be more resistant to a pressure loading, applied in a direction perpendicular to the leading edge and connecting the leading edge to the trailing edge, than the other fairing elements. 16. The towing assembly as claimed in claim 12, in which the mitered fairing element comprises two parts back to back along the first bearing edge, the fairing element being configured to be kept in a deployed configuration when subjected to the hydrodynamic flow of the water, the two parts being arranged, relative to one another about the first bearing edge, in such a way that the fairing element has a trailing edge parallel to the leading edge and a cross section that is constant along the leading edge, and configured in such a way as to allow relative pivoting between the two parts about the first bearing edge when a torque inducing relative pivoting between the two parts, applied about an axis formed by the first bearing edge, exceeds a predetermined threshold so that the fairing element passes from the deployed configuration into a configuration folded about the bearing edge. 17. The towing assembly as claimed in claim 12, wherein the fairing comprises a plurality of fairing portions, each fairing portion comprising a plurality of fairing elements joined together along the axis of the elongate element and articulated to one another, the fairing portions being free to rotate about the axis of the elongate element relative to one another, and wherein of said portions, at least one comprises at least one end fairing element, adjacent to one single other fairing element belonging to said portion, having a bearing edge comprising a first bearing edge which is mitered with respect to the leading edge, the first bearing edge being arranged in such a way that the distance between the leading edge and the first bearing edge, considered perpendicular to the leading edge, decreases continuously, along an axis parallel to the leading edge, from a first end of the first bearing edge to a second end of the first bearing edge, further away from the other fairing element than the first end, along the axis parallel to the leading edge.
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이 특허에 인용된 특허 (3)
Hale Neville E. (Mississauga CAX), Fairing assembly for towed underwater cables.
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