Tilting Flettner-type rotating rig

Abstract

The invention relates to a Flettner rotating rig (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) continuously linked to the lower aerodynamic surface (121) by disconnectable linking means (125, 321, 322); and tilting means (250) comprising a pivot joint (150) about an axis in 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 linking means (125, 321, 322) are disconnected, the upper section (102) is able to pivot about the pivot joint (150) relative to the lower section (101).

Description

Title of the invention: Tiltable Flettner-type rotating rigging technical field

[0001] The invention belongs to the field of sail propulsion, more particularly the invention relates to a rotating rig of the Flettner type, adapted to the propulsion of a ship, in main propulsion mode or in assistance to another propulsion mode. Previous technique

[0002] Wind propulsion, in main propulsion mode or as an assistance, is a means of reducing the carbon footprint of maritime transport.

[0003] Among the means of sail propulsion envisaged for this type of application, rotating sails of the Flettner type, 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 needing to orient the sail and with a reduced bulk compared to a static flexible or rigid sail.

[0004] However, the addition of these rigging systems, which can exceed 50 m in height from the ship's deck, presents difficulties, particularly for passing under bridges when transiting estuaries, or in relation to port facilities. The windage of the rotating rigging, and therefore its impact on the ship's fuel consumption when sailing into headwinds or on the ship's stability when sailing in strong winds, are also factors limiting the acceptable size of Flettner-type rigging.

[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 rotating rig of the Flettner type such an operation is clearly more complex due to the weight of the rigging and the presence of the drive and guidance devices for the rotation of the rigging.

[0006] US document 4,401,284 describes an inflatable rotating rig; this type of device is difficult to adapt to Flettner-type rigs whose dimensions are related to the propulsion needs of the ships targeted by the invention.

[0007] US patent 4,602,584 describes a vessel equipped with a Flettner-type rotating rig, comprising at its base, substantially at deck level, a hinge mechanism allowing the rotating rig to be lowered by tilting it onto the deck. This type of mechanism is also difficult to adapt to large rotating rigs weighing several tens of tons; moreover, it requires shrouds to hold the rotating rig in position, which encumber the deck. Summary of the invention

[0008] The invention aims to overcome the drawbacks of the prior art and, to this end, relates to a Flettner-type rotating rigging extending in a vertical direction over a height H measured from a base, around an axis of rotation, configured to rotate about 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 joint along an axis in 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 linking means are disconnected, the upper section is able to pivot around the pivot joint relative to the lower section.

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

[0013] The Flettner rotating 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 allows the upper section to be tilted by a tilting angle of the order of 180° relative to the lower section.

[0015] Advantageously the lower section includes an internal tower extending from the base to a height less than or equal to the height h. This configuration makes it possible to concentrate the weight of the Flettner rotating rigging mainly in the lower section and to reduce the weight of the upper section to facilitate its 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 rotational drive means is configured to drive the tower in rotation and the lower aerodynamic surface is linked in rotation to the tower.

[0017] The tower may include a tower structure made of a material consisting mainly of wood fibers.

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

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

[0020] Advantageously, the tilting means comprise a tilting device configured such that the upper section is moved in the vertical direction before pivoting about the axis of the pivot joint. This embodiment allows the centering and connecting means between the lower and upper sections to be disconnected via the tilting kinematics imposed by the tilting device.

[0021] According to one embodiment, the tilting device is configured so that the axis of the pivot joint moves from the inside of an envelope diameter of the lower section to the outside of the envelope diameter of the lower section during a 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 greater than 160°.

[0023] Advantageously, the Flettner rotating rigging includes a rotational balancing device for 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 rotational balancing device comprises a plurality of weights and means for moving each weight along an inner circumference of the upper section.

[0026] The Flettner rotating rig may include a plurality of accelerometers distributed over a height of the lower and upper aerodynamic surfaces 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 based on information received from accelerometers;

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

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

[0030] disconnect the disconnectable means;

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

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

[0033] connect the disconnectable means;

[0034] drive the rotating rigging into rotation according to a measurement cycle and measure a vibration by means of the plurality of accelerometers;

[0035] calculate using the calculation 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, but not limiting, embodiments set forth below with reference to [Fig. 1] to [Fig. 9] in which: Fig. 1

[0038] [Fig.1] shows, according to a partial cross-sectional front view, a principle example of a Flettner rotating rigging equipped with a tilting mechanism; Fig. 2

[0039] [Fig.2] is a partial cross-sectional view of an example of a rigging embodiment Flettner rotary table with two aligned sections Fig.3

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

[0041] [Fig.4] shows, in partial view, the Flettner rotating rigging of [Fig.2] in which the upper section is tilted at a tilting angle of approximately 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 rotational balancing device for the upper section of the Flettner rotating 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 rotating rigging. Fig. 7

[0044] [Fig.7] represents, in a schematic front view, an example of an embodiment of the Flettner rotating rigging including a balancing control device; Fig. 8

[0045] [Fig.8] shows in front view and in partial section an example of an embodiment of Flettner-type rotating rigging including an example of an embodiment of a tower structure comprising a truss assembly and a top view of the tower structure, the top view and the front view not being to the same scale; and Fig. 9

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

[0047] [Fig. 1] According to an exemplary embodiment, a Flettner rotating rig (100) adapted for ship propulsion extends to a height H (10), commonly greater than 50 meters from a deck (30) of the ship, over a substantially cylindrical external aerodynamic surface (121, 122) contained within an envelope diameter D (20), greater than 3 meters, commonly greater than 5 meters and less than or equal to 7 meters. Thus, a slenderness ratio 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 with a constant diameter over its height.

[0049] The weight of such a Flettner rotating rig is on the order of tens of tons, commonly from 30 to 50 tons. Consequently, tilting and then returning the entire Flettner rotating rig to its vertical position would require substantial resources, especially since during the tilting movement it would be subjected to its own weight, which would necessitate 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 rig is rotated about a vertical axis (110) at a rotation speed such that the tangential speed to the external aerodynamic surface (121, 122) is on the order of or greater than 2 times the speed of a wind to which the rotating Flettner rig is subjected, which leads to a rotation 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 rotating rig includes within 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 one embodiment, the tower (131, 132) comprises a tower structure made of a material including wood fibers.

[0053] On a second section of the Flettner rotating rig, called the upper section (102), the aerodynamic surface (122) is rotationally linked to the lower section, for example via an appropriate interface (125) implementing complementary forms, 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 about the vertical axis (110) by suitable means and guided in rotation around the tower. In this case, the ferrules (140) are bearings incorporating means for guiding rotation around the tower, for example, roller 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 embodiment examples, of an assembly of lightweight wood-based panels, a fiber-reinforced composite material, or even stretched fabric. This assembly includes reinforcement means (not shown), for example in the form of metal hoops or hoops made of composite material at the connections with the tower and at the interface (125) connecting the two sections (101, 102).

[0057] The Flettner rotating rigging includes at a height h (15) a pivot joint (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] A person skilled in the art understands that the tilting around the joint can be achieved by a more complex kinematic than simple pivoting and can include, for example, a vertical translation of the second section (102) to retract the rotating joint (125) around the vertical axis (110) between the sections before performing the pivoting around the pivot joint (150).

[0059] Insofar as the upper section (102) does not include a rotational link with the tower and this section is significantly lighter than the lower section, the means required for this tilting are significantly simplified compared to tilting the entire Flettner rotating rigging.

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

[0061] [Fig.2], thus, according to one embodiment, the tilting mechanism is placed inside the Flettner rotating rigging.

[0062] To this end, the lower section (101) comprises at its apex 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 fully connected to the lower aerodynamic surface (121) and the upper platform (212) is fully connected to the upper aerodynamic surface (122).

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

[0064] According to this 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 around a pivot axis outside the envelope diameter of the lower section.

[0065] Such kinematics allows centering and rotational driving means to be decoupled and coupled between the lower aerodynamic surface (121) and the upper aerodynamic surface (122).

[0066] Thus, according to an example embodiment [Fig.3] the ends of the upper and lower sections include 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 previously indicated, the kinematics imposed by the tilting device (250) allows, during the extension of the cylinder(s) (251) and via the connecting rods, the upper section to be lifted so as to separate the respective centering surfaces (321, 322) of the lower and upper sections, before pivoting around a pivot axis external to the outer envelope of the lower section.

[0068] A rotation angle of the Flettner rotating 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 tilt of approximately 90° of the upper section (102) relative to the vertical axis (110) of the lower section (101). In certain circumstances, for example for passing a point such a tilt angle (300), or even less, 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 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 by a laser tracker. To this end, according to one embodiment, the lower and upper sections include optical targets (not shown) for measuring the relative position and orientation of the upper section with respect to the lower section. This information is advantageously used to control the actuator (251) of the tilting device.

[0073] According to one embodiment the upper section includes one or more rotational balancing devices (422).

[0074] [Fig.5] according to an example of an 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) to radially and individually move each mass (510) of the plurality.

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

[0076] According to another embodiment (not shown) the balancing device comprises a hollow torus with a diameter equivalent to an inside 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 rotating rigging includes a plurality of accelerometers (751, 752, 753, 754) installed, for example, on the envelopes constituting the aerodynamic surfaces (121, 122) of the lower and upper sections, preferably on the inner 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) includes a file defining, for each identifier, a position of the accelerometer on the Flettner rotating rigging and a program computer technology allowing, from acquired signals, the determination of a balancing defect in the Flettner rotating rigging according to one or more planes.

[0081] Thus, after a tilting and realignment maneuver of the upper section of the Flettner rotating rigging, a measurement and balancing cycle is launched consisting of making the Flettner rotating rigging complete at least one turn, 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 carried out during the balancing procedure in order to determine the rotational imbalance of the Flettner rotating rigging.

[0083] In order to limit the vibrations of the Flettner rotating rig, it is made according to a light and rigid structure, making it possible to shift the first resonance frequencies in bending of the rig away from the rotation frequency of the Flettner rotating rig,

[0084] The rotation speed N in rpm of the Flettner rotating rig 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 rotating rigging of 100 rpm the main frequency of excitation is 1.67 Hz, and for a rotation speed of 150 rpm the main frequency of excitation is 2.5 Hz.

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

[0087] The tower structure can be a solid tubular structure made up of beams or panels assembled end to end, or an open-frame structure made up of crossed rafters with bracing or trusses arranged according to a lattice structure.

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

[0089] Truss beams (850), also made of wood or a technical derivative of wood, extend in a truss structure between the chord beams (830).

[0090] The framework thus formed may include a lower ferrule (871) for its connection with a fixed base or a rotating drive device.

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

[0092] The connections between the chord beams (830) and the truss 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 cross-laminated layers of dried solid wood planks, selected from among fir, spruce, maritime pine, Scots pine and Douglas fir or combinations thereof, without these examples being limiting. The mechanical properties of these panels are sufficient to allow their use, without additional framing, as flooring, walls or bracing.

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

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

[0097] The panels can be assembled together by means of a system of metal tongue and groove joints and bolted seams,

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

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

[0100] Regardless of the method of implementation of the tower structure, the structural elements made of wood or technical wood derivatives can be protected from the environment by fungicide treatments and marine protective varnishes.

[0101] The above description and the examples of embodiment show that the invention achieves the objectives intended, in particular it makes it possible to reduce the height of a large Flettner rotating rig by tilting a lighter upper part of this Flettner rotating rig, facilitating and accelerating such a maneuver compared to the solutions of the prior art.

Claims

Demands

1. Rotating Flettner 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 about 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) continuously linked to the lower aerodynamic surface (121) by disconnectable connecting means (125, 321, 322);and tilting means (250) comprising a pivot joint (150) about an axis in 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 linking means (125, 321, 322) are disconnected, the upper section (102) is able to pivot about the pivot joint (150) relative to the lower section (101).

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

3. Flettner rotating 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. Rotating Flettner rigging according to claim 1, wherein the tilting means comprise 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 joint.

5. Flettner rotating rigging according to claim 4, wherein the rocking device (250) is configured so that the axis of the pivot joint moves from the inside of an envelope diameter (20) of the lower section (101) to the outside of the envelope diameter of the lower section during a rocking of the upper section (102) relative to the lower section (101).

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

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

9. Flettner rotating rig 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) as a function of the information received from the accelerometers; control means for modifying a configuration of the balancing device.

10. A method for tilting a Flettner rotating rig according to claim 9, the upper and lower sections 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 into alignment with the lower section; connecting the disconnectable means; rotating the rotating rig through a measurement cycle and measuring vibration using the plurality of accelerometers; calculating a balancing device configuration using the computing center; applying the calculated configuration to the balancing device,

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