Flettner type tilting rotary rigging

Abstract

The invention relates to a Flettner rotary rigging (100) extending in a vertical direction around an axis of rotation (110) comprising: a lower section (101) comprising a lower aerodynamic surface (121) linked to a rotational drive means; an upper section (102) comprising an upper aerodynamic surface (122) linked in continuity to the lower aerodynamic surface (121) by disconnectable connecting means (125, 321, 322); and tilting means (250) comprising a pivot connection (150) along an axis of a direction secant to the vertical direction, between the lower section (101) and the upper section (102) at a height h (15) measured from the base (30), configured so that when the disconnectable connection means (125, 321, 322) are disconnected, the upper section (102) is able to pivot around the pivot connection (150) relative to the lower section (101).

Description

Title of the invention: Tilting Flettner type rotary rigging Technical field

[0001] The invention belongs to the field of sail propulsion, more particularly the invention relates to a Flettner type rotary rigging, suitable for the propulsion of a ship, in main propulsion mode or in assistance of another propulsion mode. Prior art

[0002] Sail propulsion, whether as primary propulsion or as assistance, is a way of reducing the carbon footprint of maritime transport.

[0003] Among the means of sail propulsion envisaged for this type of application, Flettner type rotary sails, using the Magnus effect, are interesting because they make it possible to generate a sail thrust force in a wider range of wind conditions, without the need to orient the sail and with reduced bulk compared to a flexible or rigid static sail.

[0004] However, the addition of these riggings, the height of which can exceed 50 m from the deck of the ship, is not without posing difficulties, particularly when crossing bridges when passing through estuaries, or with regard to port installations. The windage of the rotating rigging and therefore its impact on the consumption of the ship when sailing in a headwind or on the stability of the ship when sailing in a strong wind are also factors limiting the acceptable size of Flettner type riggings.

[0005] While flexible sails can be lowered and the masts carrying these sails inclined so as to limit their height, in the case of a Flettner type rotary rigging such an operation is significantly more complex due to the weight of the rigging and the presence of the devices for driving and guiding the rotation of the rigging.

[0006] Document US 4,401,284 describes an inflatable rotating rigging, this type of device is difficult to adapt to Flettner type rigging whose dimensions are related to the propulsion needs of the ships covered by the invention.

[0007] Document US 4,602,584 describes a ship equipped with a Flettner type rotary sail, comprising at its base, substantially at the level of the ship's deck, an articulation mechanism allowing the rotary rigging to be lowered by tilting it onto the deck. This type of mechanism is also difficult to adapt to large rotary riggings whose weight reaches several tens of tons; it also requires shrouds to hold the rotary rigging in its position, which clutter up the deck. Summary of the invention

[0008] The invention aims to resolve the drawbacks of the prior art and relates to this end to a Flettner type rotary rigging extending in a vertical direction over a height H measured from a base, around an axis of rotation, configured to rotate around this axis of rotation, comprising:

[0009] a lower section comprising a lower aerodynamic surface linked to a rotational drive means;

[0010] an upper section comprising an upper aerodynamic surface continuously connected to the lower aerodynamic surface by disconnectable connecting means; and

[0011] tilting means comprising a pivot connection along an axis of a direction secant to the vertical direction, between the lower section and the upper section at a height h measured from the base, configured so that when the disconnectable connection means are disconnected, the upper section is able to pivot around the pivot connection relative to the lower section.

[0012] Thus, the upper section of the rotating rigging can be tilted around the pivot connection at height h so as to reduce the height of the rotating rigging.

[0013] The Flettner rotary rigging can be implemented according to the embodiments and variants set out below which are to be considered individually or according to any technically operative combination.

[0014] The height h is preferably greater than or equal to a height H / 2., which makes it possible to tilt the upper section by a tilt angle of the order of 180° relative to the lower section.

[0015] Advantageously, the lower section comprises an inner tower extending from the base over a height less than or equal to the height h. This configuration makes it possible to concentrate the weight of the Flettner rotary rigging mainly in the lower section and to reduce the weight of the upper section to facilitate tilting maneuvers.

[0016] According to alternative embodiments, the tower is fixed and the lower aerodynamic surface is guided in rotation around the tower or the rotation drive means is configured to drive the tower in rotation and the lower aerodynamic surface is rotationally linked to the tower.

[0017] The tower may comprise a tower structure made of a material comprising predominantly wood fibers.

[0018] The aerodynamic surfaces may comprise an assembly of panels made of a material selected from wood, a composite material and a canvas.

[0019] These embodiments make it possible to reduce the weight of the Flettner rotary rigging while giving it great rigidity, particularly in bending perpendicular to the axis of rotation.

[0020] Advantageously, the tilting means comprise a tilting device configured so that the upper section is moved in the vertical direction before pivoting around the axis of the pivot connection. This embodiment makes it possible to disconnect the centering and connection means between the lower section and the upper section via the tilting kinematics imposed by the tilting device.

[0021] According to one embodiment, the tilting device is configured such that the axis of the pivot connection moves from inside an envelope diameter of the lower section to outside the envelope diameter of the lower section during tilting of the upper section relative to the lower section.

[0022] Advantageously, the tilting device is configured to tilt the upper section relative to the lower section by a tilting angle of at least 90° and preferably the maximum tilting angle of the upper section relative to the lower section is greater than 160°.

[0023] Advantageously, the Flettner rotary rigging comprises a device for balancing the rotation of the upper section.

[0024] According to one embodiment, the rotational balancing device comprises a plurality of masses and means for controlling the radial position of each net of the plurality.

[0025] According to another embodiment, which can be combined with the previous one, the rotation balancing device comprises a plurality of weights and means for moving each weight along an inner circumference of the upper section.

[0026] The Flettner rotary rigging may comprise comprising a plurality of accelerometers distributed over a height of the lower airfoil and the upper airfoil and a computing center configured to acquire vibration information from the plurality of accelerometers, and comprising:

[0027] calculation means for determining a configuration of the balancing device as a function of the information received from the accelerometers;

[0028] control means for modifying a configuration of the balancing device.

[0029] According to this latter embodiment, a method for tilting the Flettner rotary rigging, the upper section and the lower section being aligned and connected, comprises the steps of:

[0030] disconnect the disconnectable means;

[0031] pivot the upper section relative to the lower section;

[0032] pivot the upper section in the opposite direction to bring it back into alignment with the lower section;

[0033] connect the disconnectable means;

[0034] driving the rotating rigging to rotate according to a measurement cycle and measuring a vibration using the plurality of accelerometers;

[0035] calculating by means of the computing center a configuration of the balancing device;

[0036] apply the calculated configuration to the balancing device, Brief description of the drawings

[0037] The invention is implemented according to the preferred embodiments, which are in no way limiting, set out below with reference to [Fig.l] to [Fig.9] in which: Fig.l

[0038] [Fig.l] shows in a front view in partial section an example of the principle of a Flettner rotary rigging provided with a tilting mechanism; Fig.2

[0039] [Fig.2] is a partial sectional view of an exemplary embodiment of a rigging Flettner rotary whose two sections are aligned Fig. 3

[0040] [Fig.3] shows in partial view, the Flettner rotary rigging of [Fig.2] in which the upper section is tilted at a tilt angle of around 90° relative to the lower section; Fig.4

[0041] [Fig.4] shows in partial view, the Flettner rotary rigging of [Fig.2] in which the upper section is tilted at a tilt angle of around 170° relative to the lower section; Fig.5

[0042] [Fig.5] shows in a perspective view from above a first example of construction of a rotation balancing device for the upper section of the Flettner rotary rigging; Fig.6

[0043] [Fig.6] shows a second example of the embodiment of a balancing device in rotation of the upper section of the Flettner rotary rigging. Fig.7

[0044] [Fig.7] shows a schematic front view of an example of an embodiment of the Flettner rotating rigging including a balance control device; Fig.8

[0045] [Fig.8] represents in front view and in partial section an example of the realization of a Flettner type rotary rigging comprising an exemplary embodiment of a tower structure comprising a lattice girder assembly and a top view of the tower structure, the top view and the front view are not to the same scale; and Fig.9

[0046] [Fig.9] represents in front view and in partial section an example of an embodiment of a Flettner type rotating rigging comprising an exemplary embodiment of a tower structure made of cross-laminated timber panels and a top view of the tower structure, the top view and the front view are not to the same scale. Description of the embodiments

[0047] [Fig. 1] according to an exemplary embodiment, a Flettner rotary rigging (100) adapted to the propulsion of a ship, extends according to a height H (10), commonly greater than 50 meters relative to a deck (30) of the ship, according to an external aerodynamic surface (121, 122) substantially cylindrical included in an envelope diameter D (20), greater than 3 meters, commonly greater than 5 meters and less than or equal to 7 meters. So that a slenderness coefficient defined by a ratio H / D is between 5 and 10, commonly between 5 and 8.

[0048] The term "cylindrical" is not limited to a straight cylinder of constant diameter over its height.

[0049] The weight of such a Flettner rotary rigging is a few dozen tons, commonly 30 to 50 tons. Consequently, tilting and then returning the entire Flettner rotary rigging to a vertical position would require significant resources, especially since during the tilting movement it would be subject to its own weight, which would require the installation of auxiliary support means such as shrouds and controlled winches.

[0050] In use, that is to say to provide a propulsion force capable of moving the ship forward, the Flettner rigging is rotated about a vertical axis (110) at a rotational speed such that the tangential speed to the external aerodynamic surface (121, 122) is of the order of or greater than 2 times the speed of a wind to which the rotating Flettner rigging is subjected, which leads to a rotational speed of between 100 and 300 revolutions / minute, commonly between 100 and 200 revolutions / minute and most often between 100 and 150 revolutions / minute.

[0051] The Flettner rotary rigging comprises inside the aerodynamic surface a tower (131, 132) which ensures its vertical rigidity and the transmission of the sail thrust force to the ship.

[0052] The aerodynamic surface (121) is, at least on a section called the lower section (101), connected by ferrules (140) to the tower (131, 132). According to an exemplary embodiment, the tower (131, 132) comprises a tower structure made of a material comprising wood fibers.

[0053] On a second section of the Flettner rotary rigging, called the upper section (102), the aerodynamic surface (122) is linked in rotation to the lower section, for example via a suitable interface (125) implementing complementary shapes, without being connected to the tower (131, 132).

[0054] According to one embodiment, the tower (131, 132) is fixed and the aerodynamic surface (121, 122) is driven in rotation around the vertical axis (110) by appropriate means and guided in rotation around the tower. In this case the ferrules (140) are bearings implementing means for guiding in rotation around the tower, for example bearings (not shown).

[0055] According to another embodiment, the tower is driven in rotation around the vertical axis (110), the ferrules (140) are then means of complete connection between the tower (131, 132) and the aerodynamic surface (121) of the lower section (101).

[0056] The aerodynamic surface (121, 122) is made up, according to exemplary embodiments, of an assembly of lightweight panels made from wood, a composite material with fiber reinforcement, or even stretched canvas. This assembly comprises reinforcement means (not shown), for example in the form of metal hoops or hoops made from composite material at the level of the connections with the tower and at the level of the interface (125) connecting the two sections (101, 102).

[0057] The Flettner rotary rigging comprises at a height h (15) a pivot connection (150) whose pivot axis extends along an axis other than vertical, and preferably horizontal, linking the upper section (102) to the lower section (101) so that the upper section (102) can tilt relative to the lower section (101) by rotation around this pivot axis.

[0058] Those skilled in the art understand that the tilting around the connection can be achieved by more complex kinematics than simple pivoting and can comprise, for example, a vertical translation of the second section (102) to retract the rotating connection (125) around the vertical axis (110) between the sections before performing the pivoting around the pivot connection (150).

[0059] Since the upper section (102) does not include a rotational connection with the tower and this section is significantly lighter than the lower section, the means necessary for this tilting are significantly simplified compared to tilting the entire Flettner rotary rigging.

[0060] Thus the weight of the second section (102) is of the order of a few tonnes, typically 5 to 10 tonnes depending on the height h, compared to several tens of tonnes for the entire Flettner rotary rigging.

[0061] [Fig.2], thus, according to an exemplary embodiment, the tilting mechanism is placed inside the Flettner rotary rigging.

[0062] To this end, the lower section (101) comprises at its top a lower platform (211) and the upper section (102) comprises at its proximal end with the lower section, an upper platform (212). The lower platform (211) is connected in complete connection to the lower aerodynamic surface (121) and the upper platform (212) is connected, in complete connection, to the upper aerodynamic surface (122).

[0063] According to this embodiment, when the lower section and the upper section are coupled with their aerodynamic surfaces (121, 122) in continuity with each other, the tilting device (250), as well as the pivot axis, are located inside the envelopes of the upper and lower sections and are not visible from the outside of the Flettner rotary rigging and thus do not disturb the aerodynamic flows on the surfaces of the sail.

[0064] According to this exemplary embodiment, the tilting device (250) comprises a plurality of connecting rods and is controlled by one or more hydraulic, electric or pneumatic cylinders (251), so that the tilting kinematics produces a vertical translation of the upper section before pivoting about a pivot axis outside the envelope diameter of the lower section.

[0065] Such kinematics makes it possible to decouple and couple centering and rotational drive means between the lower aerodynamic surface (121) and the upper aerodynamic surface (122).

[0066] Thus, according to an exemplary embodiment [Fig. 3] the ends of the upper and lower sections comprise complementary surfaces (321, 322), for example conical, which ensure the centering of the two sections relative to each other and participate in the transmission of the rotational drive around the vertical axis (110) of the upper section by the lower section.

[0067] As indicated previously, the kinematics imposed by the tilting device (250) allows, during the extension of the jack(s) (251) and by means of the connecting rods, to lift the upper section so as to separate the respective centering surfaces (321, 322) of the lower and upper sections, before carrying out the pivoting around a pivot axis external to the external envelope of the lower section.

[0068] A rotation angle of the Flettner rotary rigging around the vertical axis (110), prior to tilting, while the two sections (101, 102) are still coupled, makes it possible to define the angular position around the vertical axis (110) of the pivot axis of the upper section (102) relative to the lower section and thus to position, for example, the upper section (102) relative to the deck of the ship and around the vertical axis (110).

[0069] [Fig.3] shows a tilting of the order of 90° of the upper section (102) relative to the vertical axis (110) of the lower section (101). In certain circumstances, for example for the passage of a point, such a tilting angle (300), or even lower, may be sufficient.

[0070] [Fig.4] advantageously, the final tilting angle (400) of the upper section, defined relative to the vertical axis (110) of the lower section, is greater than 160°, preferably greater than 170° and close to 180°.

[0071] According to this exemplary embodiment, the tilting angle depends on the displacement imposed by the cylinder (251) of the tilting device (250) and can be controlled by the extension distance of this cylinder.

[0072] Advantageously, this tilting angle can also be measured remotely by any optical means, in particular of the Laser Tracker type. To this end, according to an exemplary embodiment, the lower section and the upper section comprise optical targets (not shown) making it possible to measure the relative position and orientation of the upper section with respect to the lower section. This information is advantageously used to control the cylinder (251) of the tilting device in a servo-controlled manner.

[0073] According to an exemplary embodiment, the upper section comprises one or more rotation balancing devices (422).

[0074] [Fig.5] according to an exemplary embodiment such a balancing device (422J comprises a plurality of masses (510) and means such as a worm screw (520) driven by a stepper motor (530) for radially and individually moving each mass (510) of the plurality.

[0075] [Fig.6] according to another exemplary embodiment the balancing device (4222) comprises a plurality of weights (610) each movable individually on a toothed crown (620) along an inner circumference of the upper section, by means of a stepping motor (630).

[0076] According to another embodiment (not shown) the balancing device comprises a hollow torus with a diameter equivalent to an internal diameter of the upper section, which hollow torus is filled with a powdery material such as sand.

[0077] These embodiments of the rotational balancing device can be combined on the same section at different heights.

[0078] [Fig.7] To this end, the Flettner rotary rigging comprises a plurality of accelerometers (751, 752, 753, 754) installed, for example, on the envelopes constituting the aerodynamic surfaces (121, 122) of the lower section and the upper section, preferably on the internal face of this envelope so that the accelerometers are relatively protected from the environment.

[0079] Said accelerometers provide a signal proportional to a vibration level, this signal is transmitted, for example via a WiFi® type link to a computing center (790) with an identifier specific to each accelerometer.

[0080] Said computing center (790) comprises a file defining for each identifier a position of the accelerometer on the Flettner rotary rigging and a program computer allowing to determine from the acquired signals a balance defect of the Flettner rotary rigging according to one or more planes.

[0081] Thus, after a tilting and re-alignment maneuver of the upper section of the Flettner rotary rigging, a measurement and balancing cycle is launched consisting of making the Flettner rotary rigging perform at least one revolution, acquiring the signals from the accelerometers, deducing an imbalance and a correction from the computer program of the computing center (190) and applying this correction by acting on the rotating balancing devices.

[0082] Alternatively or in addition to accelerometers, a non-contact measurement, for example by laser interferometry, can also be performed during the balancing procedure in order to determine the rotational imbalance of the Flettner rotary rigging.

[0083] In order to limit the vibrations of the Flettner rotary rigging, it is made using a light and rigid structure, making it possible to offset the first resonance frequencies in bending of the rigging, from the rotation frequency of the Flettner rotary rigging,

[0084] The rotation speed N in rpm of the Flettner rotary rigging is such that the tangential speed on the aerodynamic surface is greater than 2 times the apparent wind speed.

[0085] Thus, for a rotation speed N of the Flettner rotary rigging of 100 rpm the main stress frequency is 1.67 Hz, and for a rotation speed of 150 rpm the main stress frequency is 2.5 Hz.

[0086] For this purpose, a lower section of the tower (131) comprises a tower structure made of wood or a technical derivative of wood such as glued laminated timber, cross-laminated timber, laminated wood or a composite reinforced with wood fibers such as bamboo fibers.

[0087] The tower structure may be a solid tubular structure made up of joined beams or panels, or an openwork frame structure made up of crossed rafters with cross-bracing or trusses organized in a lattice structure.

[0088] [Fig.8] according to an exemplary embodiment the tower structure is in openwork frame (800) and comprises a lattice structure (800) comprising at least one ferrule (870), for example in its upper section, to which are connected vertically extending chord beams (830). The chord beams (830) may be made of wood or a technical derivative of wood such as glued laminated wood or laminated wood without these examples being limiting.

[0089] Lattice beams (850), also made of wood or a technical derivative of wood, extend in a lattice structure between the member beams (830).

[0090] The frame thus formed may comprise a lower ferrule (871) for its connection with a fixed base or a rotation drive device.

[0091] The ferrules may be made of wood or a technical derivative of wood, a metallic material, such as steel, a light aluminum alloy, a titanium alloy, a composite material with a thermosetting or thermoplastic organic matrix reinforced by continuous fibers of glass, carbon, or biosourced organic fibers such as linen, hemp or bamboo.

[0092] The assemblies between the member beams (830) and the lattice beams (850) can be made by nailed or screwed steel fittings.

[0093] [Fig.9] according to the tower structure is a solid tubular structure (900) made cross-laminated timber panels, also known as CLT panels for “Cross Laminated Timber”.

[0094] Such panels are composed of several crossed layers of dried solid wood boards, of a species selected from fir, spruce, maritime pine, Scots pine and Douglas fir or combinations thereof, without these examples being limiting. Their mechanical characteristics of these panels are sufficient to be able to use them, without additional framework, as a floor, wall or bracing.

[0095] The panels (930) are flat and have a thickness of between 50 mm and 600 mm, the greatest thicknesses being used at the base of the tower structure and then of decreasing thicknesses along the vertical axis (110).

[0096] The panels are directly assembled together so as to form a hollow, hexagonal polygonal section according to the non-limiting example of [Fig.9].

[0097] The panels can be assembled together by a system of metal grooves and tongues and stitching by bolting,

[0098] Such flat panels are rigid and easy to manufacture, cut, machine and assemble.

[0099] The structure may include openings (990) to improve its interior ventilation.

[0100] Whatever the method of realization of the tower structure, the structural elements made of wood or technical derivatives of wood can be protected from the environment by fungicidal treatments and marine protection varnishes.

[0101] The above description and the exemplary embodiments show that the invention achieves the objectives sought, in particular it makes it possible to reduce the height of a large Flettner rotary rigging by tilting a lightened upper part of this Flettner rotary rigging, facilitating and accelerating such a maneuver compared to the solutions of the prior art.

Claims

Claims

1. Flettner rotary rigging (100) extending in a vertical direction over a height H (10) measured from a base (30), around an axis of rotation (110), configured to rotate around this axis of rotation, comprising: a lower section (101) comprising a lower aerodynamic surface (121) linked to a rotational drive means; an upper section (102) comprising an upper aerodynamic surface (122) linked in continuity to the lower aerodynamic surface (121) by disconnectable connecting means (125, 321, 322);and tilting means (250) comprising a pivot connection (150) along an axis of a direction secant to the vertical direction, between the lower section (101) and the upper section (102) at a height h (15) measured from the base (30), configured so that when the disconnectable connection means (125, 321, 322) are disconnected, the upper section (102) is able to pivot around the pivot connection (150) relative to the lower section (101).;

2. A Flettner rotary rigging according to claim 1, wherein the height h (15) is greater than or equal to a height H / 2.

3. A Flettner rotary rigging according to claim 1, wherein the lower section (101) comprises an inner tower (131, 132) extending from the base to a height less than or equal to the height h (15).

4. A Flettner rotary rigging according to claim 1, wherein the tilting means comprises a tilting device (250) configured so that the upper section (102) is moved in the vertical direction before pivoting about the axis of the pivot link.

5. A Flettner rotary rigging according to claim 4, wherein the tilting device (250) is configured so that the axis of the pivot link moves from inside a casing diameter (20) of the lower section (101) to outside the casing diameter of the lower section during a tilting of the upper section (102) relative to the lower section (101).

6. A Flettner rotary rigging according to claim 4, wherein the tilting device (250) is configured to tilt the section upper (102) relative to the lower section (101) by a tilting angle (300, 400) of at least 90°.

7. A Flettner rotary rigging according to claim 6, wherein a maximum tilt angle (400) of the upper section (102), relative to the lower section (101), is greater than 160°.

8. Flettner rotary rigging according to claim 1, comprising a balancing device (422) in rotation of the upper section (102).

9. A Flettner rotary rigging according to claim 8, comprising a plurality of accelerometers (751, 752, 753, 754) distributed over a height of the lower aerodynamic surface and the upper aerodynamic surface and a computing center (190) configured to acquire vibration information from the plurality of accelerometers, and comprising: computing means for determining a configuration of the balancing device (422) based on the information received from the accelerometers; control means for modifying a configuration of the balancing device.

10. A method for tilting a Flettner rotary rigging according to claim 9, the upper section and the lower section being aligned and connected, the method comprising the steps of: disconnecting the disconnectable means; pivoting the upper section relative to the lower section; pivoting the upper section in the opposite direction to bring it back into alignment with the lower section; connecting the disconnectable means; rotating the rotary rigging according to a measurement cycle and measuring a vibration by means of the plurality of accelerometers; calculating by means of the computing center a configuration of the balancing device; applying the calculated configuration to the balancing device,

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