Stabilizer system, ship, and method

Abstract

The invention relates to a stabilizer system (1) for damping an unwanted motion of a ship. The stabilizer system comprises a first stabilizing element (2) having a first rotation axis (5), a sensing and control system (3) for sensing motions of the ship, selecting an unwanted motion of the ship, and generating control signals on the basis of the selected unwanted motion. The stabilizer system comprises a water flow generation system (4) for providing an artificially generated water flow that is directed transverse to the first rotation axis. The stabilizer system comprising a drive system (6) for rotating the first stabilizing element around the first rotation axis thereby generating a stabilizing force for damping the selected unwanted motion. The invention also relates to a ship (30) comprising the stabilizer system, and to a method of damping an unwanted motion of a ship using the stabilizer system according to the invention.

Description

[0001] STABILIZER SYSTEM, SHIP, AND METHOD

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a stabilizer system for damping an unwanted motion of a ship if the ship is in use. The invention also relates to a ship comprising the stabilizer system according to the invention, and to a method of damping an unwanted motion of a ship using the stabilizer system according to the invention.

[0004] BACKGROUND OF THE INVENTION

[0005] Damping of unwanted motions of a ship such as roll motion or pitch motion is an important aspect for increasing the comfort and well-being of persons on board of a ship. Many stabilizer systems for damping unwanted motions of a ship are known. These stabilizer systems can be different in terms of the type of stabilizing elements, e.g. rotors or fins, that are used, and / or the operational state of the ship, i.e. whether the ship is stationary in a body of water, e.g. when the ship is at anchor, or is moving through the body of water at a certain speed, for which the respective stabilizer system can achieve damping of the unwanted motion of the ship.

[0006] A well-known type of stabilizer systems is based on the Magnus effect for generating a stabilizing force that can dampen an unwanted motion of a ship. This type of stabilizer system typically uses a cylindrical stabilizing element that is rotated in a water flow passing over the rotating cylindrical stabilizing element in order to generate the stabilizing force. Originally, this type of stabilizer system is used while the ship is moving through a body of water as the required water flow results from the ship moving at a sufficient speed. For optimizing the generated stabilizing force, the rotating stabilizing element or rotor is positioned substantially perpendicular to the water flow, i.e. substantially perpendicular to a longitudinal center line of the ship. Positioning the rotating stabilizing element at an angle that is different from the substantially perpendicular angle between the stabilizing element and the longitudinal center line of the ship, the stabilizing force is reduced, but also a drag force caused by the interaction between the stabilizing element and the water flow is reduced. The latter is advantageous for reducing additional fuel consumption of the ship as a result of the rotating stabilizing element that is arranged at a non-zero angle with respect to the longitudinal center line of the ship.

[0007] Stabilizer systems based on the Magnus effect have even been used for ships that are stationary in a body of water, e.g. when being at anchor. In this operational state of the ship, the water flow required for generating the stabilizing force is achieved by moving the rotating stabilizing element, which is positioned substantially perpendicular to the longitudinal center line of the ship, back-and-forth through the water along the longitudinal center line of the ship in a horizontal plane, i.e. in a plane substantially parallel to the waterline.

[0008] SUMMARY OF THE INVENTION

[0009] It is an object of the present invention to provide an improved stabilizer system for damping an unwanted motion of a ship if the ship is in use that allows an improved deployability compared to stabilizer systems based on the Magnus effect known in the art.

[0010] It is another object of the present invention to provide a ship that comprises a stabilizer system according to the invention.

[0011] It is yet another object of the present invention to provide a method of damping an unwanted motion of a ship using the stabilizer system according to the invention.

[0012] Aspects of the present invention are set out in the accompanying independent and dependent claims. Features from the dependent claims may be combined with features from the independent claims as appropriate and not merely as explicitly set out in the claims. Furthermore, all features may be replaced with other technically equivalent features.

[0013] At least one of the abovementioned objects is achieved by a stabilizer system for damping an unwanted motion of a ship if the ship is in use, the stabilizer system comprising: a first stabilizing element that, if the stabilizer system is in use, is associated with a hull of a ship, and is in contact with a body of water in which the ship is arranged, the first stabilizing element having a first rotation axis; a sensing and control system that, if the stabilizer system is in use, is associated with the ship, the sensing and control system being configured and arranged to sense motions of the ship, select an unwanted motion of the ship from the motions of the ship being sensed, and generate a plurality of control signals on the basis of the selected unwanted motion of the ship; a water flow generation system that, if the stabilizer system is in use, is associated with the ship and with the sensing and control system, the water flow generation system being configured to provide an artificially generated water flow on the basis of a first set of control signals from the plurality of control signals, and being arranged relative to the first stabilizing element to allow the artificially generated water flow to be directed transverse to the first rotation axis of the first stabilizing element; and a drive system that, if the stabilizer system is in use, is associated with the ship, the first stabilizing element, and the sensing and control system, wherein the drive system is configured and arranged to rotate the first stabilizing element around the first rotation axis on the basis of a second set of control signals from the plurality of control signals to allow that the first stabilizing element, which is exposed to the artificially generated water flow, enables generation of a stabilizing force for damping the selected unwanted motion of the ship.

[0014] Compared to known stabilizer systems based on the Magnus effect, it is an advantage of the above-mentioned embodiment of the stabilizer system according to the invention that it can dampen an unwanted motion of a ship, e.g. a roll motion or a pitch motion, when the ship is stationary in a body of water without having to move the rotating stabilizing element back-and-forth along the hull of the ship in a direction of the longitudinal center line of the ship. This results in a reduced impact of the stabilizer system according to the invention on the environment surrounding the ship thereby enabling a safer use of the stabilizer system. In addition, the deployability of the stabilizer system according to the invention is improved as damping of an unwanted motion of a ship can be achieved even in situations in which the above- mentioned back-and-forth movement of the rotating stabilizing element is not possible.

[0015] The sensing and control system, which is typically arranged on the inside of the ship, can comprise for example at least one of speed sensors, acceleration sensors, and angle sensors that are configured and arranged to sense at least one of the speed, the acceleration, and the angle of the ship as a result of the motion of the ship. The sensing and control system is configured to select an unwanted motion, e.g. roll motion or pitch motion, from the motions of the ship being sensed and to generate a plurality of control signals on the basis of the selected unwanted motion of the ship.

[0016] In the event that the sensing and control system establishes that the ship is stationary in the body of water in which the ship is arranged, the water flow generation system is activated to generate an artificial water flow on the basis of a first set of control signals of the plurality of control signals. The drive unit is activated to rotate the first stabilizing element, which is exposed to the artificially generated water flow, to enable generation of a stabilizing force for damping the selected unwanted motion of the ship. In the event that the sensing and control system establishes that the ship is moving through the body of water in which the ship is arranged, and that the generated stabilizing force is too small for sufficiently damping the selected unwanted motion of the ship, the water flow generation system can be activated to supplement the water flow to which the stabilizing element is exposed as a result of the movement of the ship through the body of water with the artificially generated water flow. In this way, the generated stabilizing force can be increased to be large enough to sufficiently damping the selected unwanted motion of the ship.

[0017] It is noted that in accordance with the stabilizer system of the invention, the first stabilizing element can have any suitable shape, e.g. cylindrical shape, spherical shape or fin shaped. The stabilizing element can be arranged in any suitable position relative to the hull of the ship as long as the artificially generated water flow is directed transverse to the first rotation axis. It is noted that depending on the location at which the stabilizing element is associated with the hull of the ship it is possible to dampen the roll motion or the pitch motion of the ship. If the stabilizing element is arranged underneath the hull or next to the hull at a location between the stern and the bow, roll motion of the ship can be dampened. If the stabilizing element is arranged at the bow or stern of the ship, pitch motion can be dampened. In the event that the stabilizing element is arranged at the stern of the ship, it can be arranged at the transom.

[0018] It is noted that in the context of the present invention rotation of the first stabilizing element around the first rotation axis can be either rotating fully around the first rotation axis or rotating over a first rotation angle that is smaller than 360°, i.e. partially rotating the first stabilizing element around the first rotation axis. The degree of rotation, i.e. fully around the first rotation axis or partially around the first rotation axis, depends on the actual shape of the stabilizing element.

[0019] Furthermore, it is noted that on the basis of the first set of control signals from the plurality of control signals provided by the sensing and control system, it is possible to adjust the flow rate of the artificially generated water flow. Standard basic performance calculations show that by directing an artificially generated water flow having a velocity of 5 knots (9.26 km / h) transverse to the first rotation axis of an exemplary embodiment of a stabilizing element that has a cylindrical shape and an effective cross-section of 0.14 m2and that rotates at 1000 rpm around the first rotation axis, a decent wave slope capacity, and therefore good stabilization performance can be achieved. To provide an artificially generated water flow having a velocity of 5 knots (9.26 km / h), a flow rate of at least 0.36 m3 / s is required. Ideally, the direction of the artificially generated water flow across the stabilizing element is in line with an imaginary line through the rolling point of the ship. It is noted that the direction of the artificially generated water flow is not always at right angles to the hull of the ship, but differs depending on the type of ship.

[0020] On the basis of the second set of control signals from the plurality of control signals provided by the sensing and control system, it is possible to change the direction of rotation of the first stabilizing element, the rotation angle in case the first stabilizing element is rotated partially around the first rotation axis, and the rotation speed in case the first stabilizing element is rotated fully around the first rotation axis.

[0021] The water flow generation system can be arranged on the inside of the hull of the ship, in which case the hull is configured to allow water to be taken in from the body of water in which the ship is arranged, and the artificially generated water flow to be directed transverse to the first rotation axis of the first stabilizing element. It is noted that if the artificially generated water flow is directed perpendicular to the first rotation axis, then the generated stabilizing force is maximal. However, the stabilizer system according to the present invention can generate a useful stabilizing force as long as the artificially generated water flow is directed transverse to the first rotating axis. In the context of this application, the artificially generated water flow is considered to be directed transverse to the first rotation axis if an acute angle between flow lines of the artificially generated water flow and the first rotation axis is at least 45°.

[0022] Based on the above, it will be clear that the stabilizer system according to the present invention is an improved stabilizer system that allows damping of an unwanted motion of a ship both when the ship is moving through a body of water in which the ship is arranged and when the ship is stationary in the body of water. Especially regarding the latter operational state of the ship, it is noted that in situations in which known stabilizer systems based on the Magnus effect cannot be used to dampen unwanted motions of the stationary ship as a result of the back-and-forth movement of the rotating stabilizing element, the stabilizer system according to the present invention can still be used due to its improved configuration including the water generation system for providing the artificially generated water flow. Therefore, the stabilizer system according to the invention has an improved deployability compared to stabilizer systems based on the Magnus effect known in the art.

[0023] In an embodiment of the stabilizer system according to the invention, the first rotation axis of the first stabilizing element, if the stabilizer system is in use, is arranged parallel to a longitudinal center line of the ship. In this case, the stabilizing element is arranged in a position that in the context of this application is referred to as a retracted position. It is noted that the stabilizing element can be a rotor having a cylindrical shape, a fin or a sphere that is associated with the hull of the ship either with one of its end parts or with both its end parts. As mentioned above, depending on the actual shape of the stabilizing element, the stabilizing element is rotated fully around the first rotation axis or rotated over a first rotation angle that is smaller than 360°, i.e. partially rotated around the first rotation axis for generating the required stabilizing force.

[0024] An advantage of the stabilizer system according to the invention compared to stabilizer systems based on the Magnus effect known in the art, is that a stabilizing force for damping an unwanted motion of the ship can be generated even when the stabilizing element is in the above-mentioned retracted position because the artificially generated water flow is directed transverse to the first rotation axis of the stabilizing element. It is noted that damping of an unwanted motion of a ship can be achieved with the stabilizing element in the retracted position both when the ship is stationary in a body of water and when the ship is moving through a body of water. This is advantageous as an operator of the stabilizer system does not need to worry about whether the stabilizing element is positioned such that the first rotation axis is arranged at a non-zero angle with respect to the longitudinal center line of the ship, which in the context of this application is referred to as an extended position, or in the above-mentioned retracted position. As the stabilizing element in accordance with the above-mentioned embodiment of the stabilizer system is in the retracted position, the risk of damage caused by contact between the stabilizing element and objects, e.g. bollards or nets, in the environment surrounding the ship can be reduced.

[0025] It is noted that if the stabilizing element is associated with the hull of the ship with one of its end parts, a swivel construction, e.g. a so-called swivel knee, can be used to transfer the stabilizing element between the above-mentioned retracted position and extended position. If the stabilizing element is associated with the hull of the ship with both its end parts, then a swivel construction can be dispensed with. In that case, the stabilizing element is then typically always in the retracted position and thus parallel to the direction of travel if the ship moves through a body of water. Consequently, the natural water flow resulting from the movement of the ship through the body of water is not directed transverse to the first rotation axis but along the first rotation axis of the first stabilizing element and therefore does not contribute to the generation of a stabilizing force. As mentioned above, it is an advantage of the stabilizer system according to the invention that a stabilizing force can be generated even while the stabilizing element is in the retracted position because the water flow generation system is configured and arranged with respect to the stabilizing element to direct the artificially generated water flow transverse to the first rotation axis of the stabilizing element.

[0026] An additional advantage of being able to generate a stabilizing force while the stabilizing element is in the retracted position is that the drag of the stabilizing element while a ship is moving through a body of water can be reduced. The drag can even further be reduced if the stabilizer system is arranged at least partially in a pocket that is provided in the hull of the ship.

[0027] In an embodiment of the stabilizer system according to the invention, the first stabilizing element, if the stabilizer system is in use, is associated with the hull of the ship at a first location and at a second location, the first rotation axis of the first stabilizing element and the longitudinal center line of the ship being arranged at a first distance from each other as seen in a direction transverse to the first rotation axis and the longitudinal center line. In this case, the stabilizing element is connected with both its end parts to the hull of the ship. The stabilizing element is in the retracted position and can generate a stabilizing force both while the ship is stationary in a body of water and while the ship is moving through a body of water because of the artificially generated water flow that is directed transverse to the first rotation axis. It is noted that the first distance should be large enough to enable the generated stabilizing force to provide a torque that is sufficient to dampen an unwanted motion of the ship. It will be clear that depending on constraints imposed by the environment of the ship, it is advantageous to maximize the first distance as in that case a smaller stabilizing force can be sufficient to provide a torque that is sufficient for stabilizing the ship. As a result of the required smaller stabilizing force, the flow rate of the artificially generated water flow and / or the rotation speed of a stabilizing element having a cylindrical shape, i.e. a rotor, can be reduced. It is also possible to change the position of the stabilizing element and the water flow generation system relative to each other to expose a smaller part of the stabilizing element to the artificially generated water flow. In accordance with any one of the aforementioned options, the power consumption of the stabilizer system can be reduced. Calculations for the above-mentioned exemplary embodiment of the first stabilizing element having a cylindrical shape and an effective cross-section of 0.14 m2show that the power consumption of the stabilizer system ranges between 1000W and 2000W per stabilizing element. In an embodiment of the stabilizer system according to the invention, the stabilizer system comprises a first connection unit and a second connection unit, wherein the first stabilizing element, if the stabilizer system is in use, is connected with the hull of the ship at the first location via the first connection unit, and at the second location via the second connection unit, the first connection unit and the second connection unit being associated with the sensing and control system, and being configured and arranged to allow adjustment of the first distance between the first rotation axis and the longitudinal center line of the ship on the basis of a third set of control signals from the plurality of control signals provided by the sensing and control system. In this way, the versatility of the stabilizer system according to the invention is enhanced because depending on constraints imposed by the environment of the ship and / or a required torque for damping un unwanted motion of the ship, the first distance can be adjusted to achieve an appropriate moment arm for the generated stabilizing force relative to a central roll point of the ship. It is noted that the first distance can be adjusted to for example a maximum distance if the stabilizing force cannot be increased any more by increasing the flow rate of the artificially generated local water flow and the rotation speed of a stabilizing element having a cylindrical shape, i.e. a rotor.

[0028] In an embodiment of the stabilizer system according to the invention, the first rotation axis of the first stabilizing element, if the stabilizer system is in use, is arranged at a non-zero angle relative to a longitudinal center line of the ship. In this case, the stabilizing element is in the above-mentioned extended position. If the ship is stationary in a body of water, e.g. the ship is at anchor, generation of a stabilizing force is only possible as a result of the artificially generated local water flow that is directed transverse to the first rotation axis of the first stabilizing element. Despite the fact the if a ship is moving through a body of water, the first stabilizing element is exposed to a natural water flow, the artificially generated water flow can improve the performance of the stabilizer system because the amount of water that is directed transverse to the first rotation axis of the first stabilizing element is increased.

[0029] In an embodiment of the stabilizer system according to the invention, the water flow generation system comprises a first water outlet unit that is associated with the sensing and control system, the first water outlet unit is provided with a first water outlet opening, and the first water outlet unit is configured and arranged to: be at least partially displaceable relative to the hull of the ship, if the stabilizer system is in use, to allow, depending on the non-zero angle at which the first rotation axis of the first stabilizing element is arranged relative to the longitudinal center line of the ship, arrangement of the first water outlet unit relative to the first stabilizing element on the basis of a fourth set of control signals from the plurality of control signals for allowing the artificially generated water flow to be directed transverse to the first rotation axis; and / or comprise a first water flow adjustment element that is arranged in the first water outlet opening, the first water flow adjustment element being configured and arranged to allow, if the stabilizer system is in use and depending on the non-zero angle at which the first rotation axis is arranged relative to the longitudinal center line of the ship, adjustment of a direction of the artificially generated water flow on the basis of a fifth set of control signals from the plurality of control signals for allowing the artificially generated water flow to be directed transverse to the first rotation axis.

[0030] In this case, the first water outlet unit of the water flow generation system is configured and arranged to allow keeping the artificially generated water flow directed transverse with respect to the first rotation axis even if the first stabilizing element is in the above-mentioned extended position. In this way, the performance of the stabilizer system can be guaranteed irrespective of whether the first stabilizing element is in the extended position or in the above-mentioned retracted position. The first water outlet unit can be provided with any suitable number of water outlet openings, e.g. 1, 2, 3, 4, 5, etc., that can be arranged in accordance with any suitable configuration depending on the required performance of the stabilizer system according to the invention.

[0031] In the event that the first water outlet unit is provided with a single water outlet opening, the single water outlet opening can have any suitable shape, e.g. round, square, rectangular. If the single water outlet opening is an elongated opening, the longitudinal center line of the elongated single water outlet opening can be arranged parallel to the first rotation axis of the stabilizing element. The single water outlet opening can have a symmetrical shape or an asymmetric shape. The shape can be narrowing, widening, winding, straight or a combination thereof along the longitudinal center line of the elongated single water outlet opening.

[0032] In the event that the first water outlet unit is provided with a plurality of water outlet openings the same considerations as mentioned above regarding the single water outlet opening apply for each water outlet opening of the plurality of water outlet openings.

[0033] The first water flow adjustment element can be configured to change the direction of the artificially generated water flow and / or adjust the amount of water and therefore the flow rate of the artificially generated water flow that is ejected from the first water outlet unit. Ideally, the direction of the artificially generated water flow across the stabilizing element is in line with an imaginary line through the rolling point of the ship. It is noted that the direction of the artificially generated water flow is not always at right angles to the hull of the ship, but differs depending on the type of ship.

[0034] In accordance with an exemplary embodiment of the stabilizer system according to the invention, the first water outlet opening can be provided with at least one of a filter element and a cover element. The cover element can be configured to allow partially or fully opening and closing of the first water outlet opening on the basis of control signals provided by the sensing and control system.

[0035] In an embodiment of the stabilizer system according to the invention, the first stabilizing element has a cylindrical shape or a spherical shape, and wherein the drive system is configured to allow rotation of the first stabilizing element, if the stabilizer system is in use, fully around the first rotation axis. A stabilizing element having a cylindrical shape is typically referred to as a rotor. Rotors are commonly applied in stabilizer systems based on the Magnus effect. The rotor could be provided with end plates that are configured to improve the stabilizing force that can be generated by the rotor. A stabilizing element having a spherical shape or a stabilizing element having multiple spherical bodies can also be applied in the stabilizer system according to the invention for generating a stabilizing force.

[0036] In an embodiment of the stabilizer system according to the invention, the first stabilizing element has a fin shape, and the drive system is configured to allow rotation of the first stabilizing element, if the stabilizer system is in use, around the first rotation axis over a first rotation angle that is smaller than 360°, wherein rotation over the first rotation angle enables arranging the first stabilizing element in a first position relative to the water flow generation system to allow generation of the stabilizing force, and wherein the first rotation angle is adjustable on the basis of the second set of control signals provided by the sensing and control system to allow adjustment of the first position and thereby of the stabilizing force.

[0037] As mentioned above, in the event that the first stabilizing element is a fin, the fin can be connected either with one of its end parts or with both its end parts to the hull of the ship. If the fin is in the above-mentioned retracted position, it is only possible to generate a stabilizing force by directing the artificially generated water flow transverse to the first rotation axis of the fin. By adjusting the first position of the fin relative to the water flow generation system, it is possible to adjust at least one of the direction and the magnitude of the stabilizing force. This applies both to a ship that is stationary in a body of water and to a ship that is moving through a body of water. Regarding the latter operational mode of the ship, it is noted that when the fin is in the retracted position, the artificially generated water flow is required for generating a stabilizing force because the natural water flow resulting from the movement of the ship through the body of water is not directed transverse to the first rotation axis but along the first rotation axis. As a result, the natural water flow does not contribute to the generation of a stabilizing force.

[0038] If the fin is in the above-mentioned extended position, i.e. the first rotation axis of the fin is arranged at a non-zero angle relative to the longitudinal center line of the ship, and the ship is stationary in a body of water, it is only possible to generate a stabilizing force by directing the artificially generated water flow transverse to the first rotation axis of the fin. By adjusting the first position of the fin relative to the water flow generation system it is possible to adjust at least one of the direction and the magnitude of the first stabilizing force.

[0039] If the fin is in the extended position while the ship is moving through the body of water, a stabilizing force can be generated as a result of the interaction of the fin with the natural water flow. However, interaction of the fin with the artificially generated water flow can improve the performance of the stabilizer system because the amount of water that is directed transverse to the first rotation axis of the fin can be increased. By adjusting the first position of the fin relative to the water flow generation system, it is possible to adjust the direction and / or the magnitude of the stabilizing force.

[0040] In an embodiment of the stabilizer system according to the invention, the first stabilizing element has a first cross-section in a direction perpendicular to the first rotation axis, the first cross-section having a first perimeter that has a first size, wherein the first stabilizing element is configured to allow adjustment of the first size of the first perimeter. In this way, the effective cross-section of the first stabilizing element that is exposed to the artificially generated water flow can be adjusted. This allows for dynamic tuning of for example the magnitude of the generated stabilizing force. Increasing the effective cross-section allows a greater stabilizing force to be generated in the event that the rotation speed of the stabilizing element and / or the flow rate of the artificially generated water flow cannot be increased any further.

[0041] In an embodiment of the stabilizer system according to the invention, the first stabilizing element, which has the cylindrical shape, has a second cross-section in a direction perpendicular to the first rotation axis, the second cross-section having a second perimeter that has a circular shape, an elliptical shape or a polygonal shape. As mentioned above, a stabilizing element having a cylindrical shape is commonly referred to as a rotor. Depending on the specific requirements for the stabilizer system, any one of the above-mentioned shapes can be used to provide an appropriate rotor.

[0042] In an embodiment of the stabilizer system according to the invention, the first stabilizing element, which has the cylindrical shape, has a third cross-section in a direction perpendicular to the first rotation axis, the third cross-section having a third perimeter that has a third size, and a fourth cross-section in the direction perpendicular to the first rotation axis, the fourth cross-section having a fourth perimeter that has a fourth size, wherein the third size of the third perimeter and the fourth size of the fourth perimeter are different. In this way, the cylindrical stabilizing element or rotor can be configured to widen along the first rotation axis. It is also possible that the rotor element comprises different interconnected sections having different perimeters and / or different perimeter shapes. For example, the rotor can comprise a first section having a circular perimeter and a second section having a polygonal perimeter. It is noted that edges between corners of the polygon do not need to be straight but can have any desired shape, e.g. curved. Any advantageous configuration of the cylindrical stabilizing element or rotor that can be envisaged can be applied in the stabilizer system according to the present invention.

[0043] In an embodiment of the stabilizer system according to the invention, the first stabilizing element, which has the fin shape, has a fifth cross-section in a direction perpendicular to the first rotation axis, the fifth cross-section having a fifth perimeter that has a fifth size, and a sixth cross-section in the direction perpendicular to the first rotation axis, the sixth cross-section having a sixth perimeter that has a sixth size, wherein the fifth size of the fifth perimeter and the sixth size of the sixth perimeter are different. In this way, the fin can be configured to widen along the first rotation axis. It is also possible that the fin comprises different interconnected sections having different perimeters and / or different perimeter shapes. For example, the rotor can comprise a third section having a symmetric perimeter and a fourth section having an asymmetric perimeter. Any advantageous configuration of the fin that can be envisaged can be applied in the stabilizer system according to the present invention.

[0044] In an embodiment of the stabilizer system according to the invention, the first stabilizing element has a first length in a direction of the first rotation axis, the first stabilizing element being configured to allow adjustment of the first length. In this way, the effective cross-section of the first stabilizing element that is exposed to the artificially generated water flow can be adjusted. This allows for dynamic tuning of for example the magnitude of the generated stabilizing force. Increasing the effective cross-section allows a greater stabilizing force to be generated in the event that the rotation speed of the stabilizing element and / or the flow rate of the artificially generated water flow cannot be increased any further. In addition to or alternatively, the size of the perimeter of the stabilizing element can adjusted as mentioned above. In accordance with an exemplary embodiment of the stabilizer system according to the invention, the stabilizing element can be configured to have a telescopic arrangement allowing adjustment of the first length.

[0045] In an embodiment of the stabilizer system according to the invention, the water flow generation system comprises a first water inlet unit that is provided with a first water inlet opening that is configured and arranged to allow, if the stabilizer system is in use, entrance into the water flow generation system of water from a body of water in which the ship is arranged. The first water inlet opening can be configured to allow scooping water from the body of water through which the ship is moving. The first water inlet opening can be provided at any suitable location at the hull of the ship. The first water inlet opening can be configured in any suitable way as for example a scoop inlet, i.e. a kind of half hood that is arranged under the waterline on the hull of the ship. The first inlet opening can have any suitable shape, for example polygonal, rectangular, trapezoid, circular, whether or not following the hull. The first water inlet unit can be provided with any suitable number of water inlet openings, e.g. 1, 2, 3, 4, 5, etc., that can be arranged in accordance with any suitable configuration depending on the required performance of the stabilizer system according to the invention. In the event that the first water inlet unit is provided with multiple water inlet openings, the individual water inlet openings can have at least one of a different shape, a different position, and a different size.

[0046] In an embodiment of the stabilizer system according to the invention, the first water inlet unit is provided with a first pump that is arranged in fluid communication with the first water inlet opening. The first pump will be required when the ship is stationary in a body of water as in this operational mode of the ship it is not possible that water is scooped by the water inlet opening. The pump can also enhance a velocity of water that is sucked into the first water inlet unit of the water flow generation system. The pump can also be used when a ship is moving through a body of water in the event that scooping of water from the body of water is insufficient for supplying enough water to the water flow generation system.

[0047] The first pump can be arranged downstream from the first water inlet opening in the first water inlet unit or upstream of the first water inlet opening depending on the specific configuration of the stabilizer system according to the invention. The first pump can be arranged within the hull, outside of the hull, and partially inside and partially outside of the hull. The first pump can be driven in any suitable way, for example electrically, hydraulically, pneumatically. The first pump can also be coupled to a main engine of the ship. The stabilizer system according to the invention can comprise multiple pumps for example to improve the redundancy and therefore the reliability of the stabilizer system.

[0048] In accordance with an exemplary embodiment of the stabilizer system according to the invention, the first water inlet opening can be provided with at least one of a filter element and a cover element. The filter element can prevent for example at least one of fish, pieces of wood, plastic, and stones when water is sucked in close to the bottom underneath a body of water from entering the water flow generation system. The filter element can for example be a simple grid or a replaceable filter. The cover element can be configured to allow partially or fully opening and closing of the first water inlet opening on the basis of control signals provided by the sensing and control system.

[0049] In accordance with another exemplary embodiment of the stabilizer system according to the invention the operation principle of the stabilizer system could be reversed, i.e. the first water outlet unit sucks water near the stabilizing element from the body of water in which the ship is arranged into the water flow generation system and the first water inlet unit ejects water into the body of water. In this way, an artificially generated water flow can be generated by sucking in water at a sufficient flow rate instead of forcing such an artificially generated water flow over the stabilizing element for generating a stabilizing force. As mentioned above, ideally, the direction of the artificially generated water flow across the stabilizing element is in line with an imaginary line through the rolling point of the ship. It is noted that the direction of the artificially generated water flow is not always at right angles to the hull of the ship, but differs depending on the type of ship.

[0050] In an embodiment of the stabilizer system according to the invention, the water flow generation system comprises a water reservoir that is arranged inside the hull of the ship, and wherein the first pump is configured and arranged to allow, if the stabilizer system is in use, entrance into the water flow generation system of water from the water reservoir. The water reservoir can be a bin, an accumulator or plenum chamber that is used to collect water from the body of water the ship is arranged in. The collected water can be fed into the water flow generation system via the first pump and the first water inlet unit.

[0051] It is noted that the flow rate of the artificially generated water flow can be adjusted dynamically depending on the stabilizing force that is required for damping an unwanted motion that varies depending on the conditions of the ship while it is arranged in a body of water, e.g. high waves due to strong wind. The water supply to the water flow generation system typically is constant. In order to always have sufficient water available in the event of changing water flow requirements, i.e. to smooth out variations in water supply requirements, the water reservoir can be used as a buffer.

[0052] In an embodiment of the stabilizer system according to the invention, the water flow generation system comprises a first water channel that is arranged in fluid communication with the first water inlet unit and the first water outlet unit. The first water channel can have at least one of a constant cross-section, a narrowing crosssection to enhance the flow rate, a widening cross-section to reduce the flow rate, at least one bend, and a fixed or adjustable length.

[0053] In an embodiment of the stabilizer system according to the invention, the first water channel is provided with at least one of a filter element, a water flow improvement unit, and a sensor. The filter element can be configured and arranged to prevent blockage of the first water channel by for example at least one of fish, pieces of wood, plastic, and stones if water is sucked in close to the bottom underneath the body of water. The water flow improvement unit can be configured to convert the water flow from a turbulent water flow into a laminar water flow. The sensor can for example be a temperature sensor, a flow sensor, or a pressure sensor.

[0054] In accordance with an exemplary embodiment of the stabilizer system according to the invention, the water flow generation system comprises a plurality of water channels. At least one of the water channels of the plurality of water channels can be provided with at least one of a filter element, a water flow improvement unit, and a sensor. The water channels of the plurality of water channels can all be configured differently.

[0055] According to another aspect of the present invention, a ship is provided comprising a stabilizer system according to the present invention. In an exemplary embodiment of the ship according to the invention, the ship comprises a stabilizer system comprising one stabilizing element.

[0056] In another exemplary embodiment of the ship according to the invention, the ship comprises a stabilizer system comprising two stabilizing elements wherein the stabilizing elements are arranged at opposite sides of the hull of the ship. As a result of the two stabilizing elements, the total stabilizing force that can be generated can be increased. An additional advantage of a stabilizer system having two stabilizing elements that are arranged at opposite sides of the hull is that dynamic positioning of the ship can be achieved as a result of a lateral displacement of the ship. Dynamic positioning of the ship could even be achieved with a stabilizer system having one stabilizing element but in that case an additional water flow would have to be provided at the other side of the hull where no stabilizing element is arranged.

[0057] In yet another exemplary embodiment of the ship according to the invention, the ship comprises a stabilizer system comprising four stabilizing elements, wherein a first pair of the four stabilizing elements is arranged at one side of the hull that is arranged between the stern and the bow, and a second pair of the four stabilizing elements is arranged at the other side of the hull that is arranged between the stern and the bow. As a result of the four stabilizing elements, the total stabilizing force that can be generated can even further be increased. Additional advantages are that the redundancy of the stabilizer system is improved, and that the above-mentioned dynamic positioning of the ship can be achieved. Yet another advantage is that the four stabilizing elements enable the stabilizer system to dampen pitching motions of the ship. This can be done both while the ship is stationary in a body of water and while the ship is moving through a body of water.

[0058] According to yet another aspect of the present invention, a method of damping an unwanted motion of a ship, if the ship is in use, is provided. The method comprising: providing a stabilizer system comprising:

[0059] • a first stabilizing element that is associated with a hull of a ship, and is in contact with a body of water in which the ship is arranged, the first stabilizing element having a first rotation axis;

[0060] • a sensing and control system that is associated with the ship;

[0061] • a water flow generation system that is associated with the ship and with the sensing and control system; and

[0062] • a drive system that is associated with the ship, the first stabilizing element, and the sensing and control system; activating the sensing and control system to:

[0063] • sense motions of the ship;

[0064] • select an unwanted motion of the ship from the motions of the ship being sensed;

[0065] • generate a plurality of control signals on the basis of the selected unwanted motion of the ship; activating the water flow generation system to provide an artificially generated water flow on the basis of a first set of control signals of the plurality of control signals, and to direct the artificially generated water flow transverse to the first rotation axis of the first stabilizing element; and activating the drive system to rotate the first stabilizing element around the first rotation axis on the basis of a second set of control signals from the plurality of control signals to allow the first stabilizing element, which is exposed to the artificially generated water flow, to generate a stabilizing force for damping the selected unwanted motion of the ship.

[0066] An advantage of applying the method according to the invention is that an unwanted motion of a ship can be dampened both when the ship is moving through a body of water in which the ship is arranged and when the ship is stationary in the body of water. Especially regarding the latter operational state of the ship, it is noted that in situations in which known stabilizer systems based on the Magnus effect cannot be used to dampen unwanted motions of the stationary ship as a result of the back-and- forth movement of the rotating stabilizing element, the stabilizer system according to the present invention can still be used due to its improved configuration including the water generation system for providing the artificially generated water flow.

[0067] In addition, it is noted that it is an advantage of applying the method according to the invention that a stabilizing force can be generated even while the stabilizing element is in the retracted position because the water flow generation system is configured and arranged with respect to the stabilizing element to direct the artificially generated water flow transverse to the first rotation axis of the stabilizing element.

[0068] BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Further features and advantages of the invention will become apparent from the description of exemplary and non-limiting embodiments of a stabilizer system according to the present invention, a ship comprising the stabilizer system according to the present invention, and a method of damping an unwanted motion of a ship using the stabilizer system according to the present invention.

[0070] The person skilled in the art will appreciate that the described embodiments of the stabilizer system, the ship comprising the stabilizer system, and the method of damping an unwanted motion of a ship using the stabilizer system according to the present invention are exemplary in nature only and not to be construed as limiting the scope of protection in any way. The person skilled in the art will realize that alternatives and equivalent embodiments of the stabilizer system, the ship, and the method can be conceived and reduced to practice without departing from the scope of protection of the present invention.

[0071] Reference will be made to the figures on the accompanying drawing sheets. The figures are schematic in nature and therefore not necessarily drawn to scale. Furthermore, equal reference numerals denote equal or similar parts.

[0072] On the attached drawing sheets, figure 1 shows a schematic side view of a first exemplary, non-limiting embodiment of a stabilizer system according to the invention; figure 2 shows a schematic side view of a second exemplary, non-limiting embodiment of the stabilizer system according to the invention; figure 3A shows a schematic side view of a ship indicating examples of locations at which the stabilizer system can be arranged; figure 3B shows a schematic front view of a ship indicating examples of how elements of the stabilizer system can be arranged relative to each other and relative to the ship; figure 3C shows a schematic cross-sectional view of a ship having a hull that is provided with pockets in which the stabilizer system according to the invention can be arranged; figure 3D shows a schematic front view of a ship that is provided with a third exemplary, non-limiting embodiment of the stabilizer system according to the invention, wherein the stabilizing elements are in a first position with respect to the hull of the ship; figure 3E shows a schematic front view of the ship comprising the third exemplary, non-limiting embodiment of the stabilizer system shown in figure 3D, wherein the stabilizing elements are in a second position with respect to the hull of the ship; figure 4A shows a schematic cross-sectional view of a ship comprising a fourth exemplary, non-limiting embodiment of the stabilizer system according to the invention, wherein the first stabilizing element is in a first position with respect to the longitudinal center line of the ship; figure 4B shows a schematic cross-sectional view of the ship comprising the fourth exemplary, non-limiting embodiment of the stabilizer system shown in figure 4A, wherein the first stabilizing element is in a second position with respect to the longitudinal center line of the ship; figure 4C shows a schematic cross-sectional view of the ship comprising the fourth exemplary, non-limiting embodiment of the stabilizer system shown in figures 4A and 4B, wherein the first stabilizing element is in a third position with respect to the longitudinal center line of the ship; figure 5 shows a schematic cross-sectional view of a part of a ship comprising a fifth exemplary, non-limiting embodiment of the stabilizer system according to the invention, wherein the first stabilizing element is in a fourth position with respect to the longitudinal center line of the ship; figures 6A-6K show schematic perspective views of exemplary, non-limiting embodiments of a stabilizing element of the stabilizer system according to the invention; figure 7A shows a schematic cross-sectional view of a ship comprising a sixth exemplary, non-limiting embodiment of the stabilizer system according to the invention; and figure 7B shows a schematic cross-sectional view of a ship comprising a seventh exemplary, non-limiting embodiment of the stabilizer system according to the invention.

[0073] DETAILED DESCRIPTION OF EMBODIMENTS

[0074] Figure 1 shows a schematic side view of a first exemplary, non-limiting embodiment of a stabilizer system 1 according to the invention. The stabilizer system 1 comprises a first stabilizing element 2 that, if the stabilizer system 1 is in use, is associated with a hull of a ship, and is in contact with a body of water in which the ship is arranged. The first stabilizing element 2 has a first rotation axis 5 around which the stabilizing element can be rotated to generate a stabilizing force. The first stabilizing element 2 is connected to a swivel construction 42 that has a second rotation axis 43. In the context of the present invention, a first position of the stabilizing element 2 in which the first rotation axis 5 of the stabilizing element 2 is arranged parallel to the longitudinal center line of the ship, is referred to as a retracted position (cfr. for example figures 4A, 4B). A second position of the stabilizing element 2 in which the first rotation axis 5 of the first stabilizing element 2 is arranged at a nonzero angle with respect to the longitudinal center line of the ship, is referred to as an extended position in the context of this application (cfr. for example figures 4C and 5). Rotation around the second rotation axis 43 of the swivel construction 42 allows, if the stabilizer system 1 is in use, transferring the stabilizing element 2 between the retracted position and the extended position.

[0075] The stabilizer system 1 comprises a sensing and control system 3 that, if the stabilizer system 1 is in use, is associated with the ship, the sensing and control system 3 being configured and arranged to sense motions of the ship, select an unwanted motion of the ship, e.g. roll motion or pitch motion, from the motions of the ship being sensed, and generate a plurality of control signals on the basis of the selected unwanted motion of the ship.

[0076] The stabilizer system 1 comprises a water flow generation system 4 that, if the stabilizer system 1 is in use, is associated with the ship and with the sensing and control system 3. Figure 1 shows a first water outlet unit 10 of the water flow generation system 4. The first water outlet unit 10 is provided with a plurality of circular water outlet openings 16. The number of water outlet openings 16 shown in figure 1 is exemplary in nature only and can be any suitable number, e.g. 1 , 2, 3, 4, 5, 10, 20 etc. For each of the water outlet openings 16 holds that they can have any suitable shape, e.g. circular, square, rectangular. It is not required that all water outlet openings 16 have the same shape or size. The arrangement of the water outlet openings 16 is also exemplary in nature only and can be any suitable arrangement.

[0077] The water flow generation system 4 is configured to provide an artificially generated water flow on the basis of a first set of control signals from the plurality of control signals, and is arranged relative to the first stabilizing element 2 to allow the artificially generated water flow to be directed transverse to the first rotation axis 5 of the first stabilizing element 2. Figure 1 schematically illustrates that the artificially generated water flow is directed perpendicular to the first rotation axis 5. Although in this case the generated stabilizing force is maximal, the stabilizer system 1 according to the present invention can generate a useful stabilizing force as long as the artificially generated water flow is directed transverse to the first rotating axis 5. In the context of this application, the artificially generated water flow is considered to be directed transverse to the first rotation axis 5 if an acute angle between flow lines of the artificially generated water flow and the first rotation axis 5 is at least 45°. The stabilizer system 1 comprises a drive system 6 that, if the stabilizer system 1 is in use, is associated with the ship, the first stabilizing element 2, and the sensing and control system 3. The drive system 6 is configured and arranged to rotate the first stabilizing element 2 around the first rotation axis 5 on the basis of a second set of control signals from the plurality of control signals to allow that the first stabilizing element 2, which is exposed to the artificially generated water flow, enables generation of a stabilizing force for damping the selected unwanted motion of the ship.

[0078] The sensing and control system 3, which is typically arranged on the inside of the ship (cfr. figures 4A, 4B, 4C), can comprise for example at least one of speed sensors, acceleration sensors, and angle sensors that are configured and arranged to sense at least one of the speed, the acceleration, and the angle of the ship as a result of the motion of the ship. In the event that the sensing and control system 3 establishes that the ship is stationary in the body of water in which the ship is arranged, the water flow generation system 4 is activated to generate an artificial water flow on the basis of a first set of control signals of the plurality of control signals. The drive unit 6 is activated to rotate the first stabilizing element 2, which is exposed to the artificially generated water flow, to enable generation of a stabilizing force for damping the selected unwanted motion of the ship.

[0079] In the event that the sensing and control system 3 establishes that the ship is moving through the body of water in which the ship is arranged, and that the generated stabilizing force is too small for sufficiently damping the selected unwanted motion of the ship, the water flow generation system 4 can be activated to supplement the water flow to which the stabilizing element 2 is exposed as a result of the movement of the ship through the body of water with the artificially generated water flow. In this way, the generated stabilizing force can be increased to be large enough to sufficiently damping the selected unwanted motion of the ship.

[0080] The first stabilizing element 2 can have any suitable shape, e.g. cylindrical shape, spherical shape or fin shaped. The stabilizing element 2 can be arranged in any suitable position relative to the hull of the ship as long as the artificially generated water flow is directed transverse to the first rotation axis 5. It is noted that in the context of the present invention rotation of the first stabilizing element around the first rotation axis can be either rotating fully around the first rotation axis or rotating over a first rotation angle that is smaller than 360°, i.e. partially rotating the first stabilizing element around the first rotation axis. The degree of rotation, i.e. fully around the first rotation axis or partially around the first rotation axis, depends on the actual shape of the stabilizing element. On the basis of the second set of control signals from the plurality of control signals provided by the sensing and control system 3, it is possible to change the direction of rotation of the first stabilizing element 2, the rotation angle in case the first stabilizing element 2 is rotated partially around the first rotation axis 5, and the rotation speed in case the first stabilizing element 2 is rotated fully around the first rotation axis.

[0081] In accordance with a method of damping an unwanted motion of a ship if the ship is in use, the method comprises providing a stabilizer system 1 comprising a first stabilizing element 2 that is associated with a hull of the ship, and is in contact with a body of water in which the ship is arranged, the first stabilizing element 2 having a first rotation axis 5, a sensing and control system 3 that is associated with the ship, a water flow generation system 4 that is associated with the ship and with the sensing and control system 3, and a drive system 6 that is associated with the ship, the first stabilizing element 2, and the sensing and control system 3. The sensing and control system 3 is activated to sense motions of the ship, select an unwanted motion of the ship from the motions of the ship being sensed, and generate a plurality of control signals on the basis of the selected unwanted motion of the ship. The water flow generation system 4 is activated to provide an artificially generated water flow on the basis of a first set of control signals of the plurality of control signals, and to direct the artificially generated water flow transverse to the first rotation axis 5 of the first stabilizing element 2. The drive system 6 is activated to rotate the first stabilizing element 2 around the first rotation axis 5 on the basis of a second set of control signals from the plurality of control signals to allow the first stabilizing element 2, which is exposed to the artificially generated water flow, to generate a stabilizing force for damping the selected unwanted motion of the ship.

[0082] An advantage of applying the method according to the invention is that an unwanted motion of a ship can be dampened both when the ship is moving through a body of water in which the ship is arranged and when the ship is stationary in the body of water. Especially regarding the latter operational state of the ship, it is noted that in situations in which known stabilizer systems based on the Magnus effect cannot be used to dampen unwanted motions of the stationary ship as a result of the back-and- forth movement of the rotating stabilizing element, the stabilizer system according to the present invention can still be used due to its improved configuration including the water generation system for providing the artificially generated water flow. Figure 2 shows a schematic side view of a second exemplary, non-limiting embodiment of the stabilizer system 1 according to the invention, wherein the first water outlet unit 10 is provided with a single water outlet opening 16 having an elongated shape. A longitudinal center line of the elongated single water outlet opening 16 can be arranged parallel to the first rotation axis 5 of the stabilizing element 2 as shown in figure 2. However, other orientations of the elongated single water outlet opening 16 can be envisaged depending on the specific requirements of the stabilizer system 1. The single water outlet opening 16 can have a symmetrical shape or an asymmetric shape. The shape can be narrowing, widening, winding, straight or a combination thereof along the longitudinal center line of the elongated single water outlet opening 16.

[0083] The first water outlet unit 10 shown in figure 2 is provided with a plurality of water flow adjustment elements 11 that are arranged in the first water outlet opening 16. It is noted that the number of water flow adjustment element 11 shown in figure 2 is exemplary in nature only. Any suitable number of water flow adjustment elements 11 can be provided depending on the specific requirements of the stabilizer system 1. If the stabilizing element 2 is in the above-mentioned extended position, the water flow adjustment elements 11 allow adjustment of a direction of the artificially generated water flow in order to ensure that the artificially generated water flow can remain directed transverse with respect to the first rotation axis 5. The water flow adjustment elements 11 can also be used to adjust the amount of water and therefore the flow rate of the artificially generated water flow that is ejected from the first water outlet unit 10.

[0084] Figure 3A shows a schematic side view of a ship indicating examples of locations at which the stabilizer system 1 can be arranged. It is noted that any suitable location not schematically indicated in figure 3A can also be considered. If the stabilizing element 2 of the stabilizer system 1 is arranged underneath the hull 31 or next to the hull 31 at a location between the stern and the bow, roll motion of the ship 30 can be dampened. If the stabilizing element 2 of the stabilizer system 1 is arranged at the transom of the ship, pitch motion can be dampened. It is noted that it can be advantageous to arrange the first stabilizing element 2 at an end part of the hull as in this way, both the moment arm relative to a central roll point of the ship 30 can be maximized.

[0085] Figure 3B shows a schematic front view of a ship 30 indicating examples of how elements of the stabilizer system 1 can be arranged relative to each other and relative to the ship 30. The exemplary embodiment of the stabilizer system 1 shown in figure 3B comprises a first stabilizing element 2 and a second stabilizing element 22 that are arranged at opposite sides of the hull 31 of the ship 30. A first assembly comprising a first pump 15, a first water outlet unit 10, and a first water outlet opening 16 has been schematically arranged at six possible locations around the first stabilizing element 2. At each of the six locations the artificially generated water flow is directed transverse to the rotation axis of the first stabilizing element. Similarly, a second assembly comprising a second pump 25, a second water outlet unit 20, and a second water outlet opening 26 has been schematically arranged at six possible locations around the second stabilizing element 22. At each of the six locations the artificially generated water flow is directed transverse to the rotation axis of the second stabilizing element 22. It is noted that figure 3B schematically represents 36 exemplary embodiments regarding the configuration of the stabilizer system falling within the scope of the stabilizer system according to the present invention.

[0086] Figure 3C shows a schematic cross-sectional view of a ship 30 having a hull 31 that is provided with a first pocket 21 and a second pocket 41 that are arranged at opposite sides of the hull 31. The first pocket 21 is configured to receive a first pump

[0087] 15, a first water outlet unit 10, and a first stabilizing element 2 of the stabilizer system according to the invention. The second pocket 41 is configured to receive a second pump 25, a second water outlet unit 20, and a second stabilizing element 22 of the stabilizer system according to the invention. An advantage of arranging the first stabilizing element 2 in the first pocket 21 and the second stabilizing element 22 in the second pocket 41 is that drag can be reduced when the ship 30 is moving through a body of water.

[0088] Figure 3D shows a schematic front view of a ship 30 that is provided with a third exemplary, non-limiting embodiment of the stabilizer system 1 according to the invention, wherein the stabilizing elements 2, 22 are in a first position with respect to the hull 31 of the ship 30. While being in this first position, a first force can be generated by rotating the first stabilizing element 2 in the artificially generated water flow that is ejected from the first water outlet unit 10 via the first water outlet opening

[0089] 16, and a second force can be generated by rotating the second stabilizing element 22 in the artificially generated water flow that is ejected from the second water outlet unit 20 via the second water outlet opening 26. The first force and the second force having a suitable force and direction to allow damping of an unwanted roll motion of the ship 30. Figure 3E shows a schematic front view of the ship 30 comprising the third exemplary, non-limiting embodiment of the stabilizer system 1 shown in figure 3D, wherein the stabilizing elements 2, 22 are in a second position with respect to the hull 31 of the ship 30. In the second position, the moment arm of the first force generated by the first stabilizing element 2 relative to the central roll point of the ship 30 is increased. As a result, if the first force has a same magnitude whether the first stabilizing element 2 is in the first position shown in figure 3D or in the second position shown in figure 3E, the torque provided by the first force when the first stabilizing element 2 is in the second position is larger than the torque provided by the first force when the first stabilizing element 2 is in the first position.

[0090] It is noted that the single-acting cylinder shown in figures 3D and 3E is an exemplary embodiment of a displacement construction that can be used for transferring the first stabilizing element 2 and the second stabilizing element 22 between the first position shown in figure 3D and the second position shown in figure 3E. The single-acting cylinder can be hydraulically or pneumatically controlled. It is possible to apply any suitable displacement construction, e.g. a double-acting cylinder or an electrically controlled cylinder comprising a linear motor.

[0091] Figure 4A shows a schematic cross-sectional view of a ship 30 comprising a fourth exemplary, non-limiting embodiment of the stabilizer system 1 according to the invention, wherein the first stabilizing element 2 is in a first position with respect to the longitudinal center line 7 of the ship 30. In the first position, the first rotation axis 5 of the first stabilizing element 2 is arranged parallel to the longitudinal center line 7 of the ship 30. As mentioned above, this is referred to as the retracted position of the first stabilizing element 2. In the first position, the first rotation axis 5 and the longitudinal center line 7 of the ship 30 are at a first distance D1 from each other as seen in a direction transverse to the first rotation axis 5 and the longitudinal center line 7.

[0092] The stabilizer system 1 comprises a water flow generation system 4 that comprises a first water inlet unit 13 that is provided with a first water inlet opening 14 that allows entrance into the water flow generation system 4 of water from a body of water in which the ship is arranged. The first water inlet opening 14 can be arranged at any suitable location at the hull of the ship, for example near the bow of the ship 30 as shown in figure 4A or at the transom of the ship 30 as shown in figure 4B. It is also possible to arrange the first water inlet opening at the keel of the ship.

[0093] The first water inlet opening 14 shown in figure 4A can scoop water from a body of water if the ship is moving. The first inlet opening 14 can have any suitable shape, for example polygonal, rectangular, trapezoid, circular, whether or not following the hull. The first water inlet unit can be provided with any suitable number of water inlet openings, e.g. 1, 2, 3, 4, 5, etc., that can be arranged in accordance with any suitable configuration depending on the required performance of the stabilizer system 1 according to the invention. In accordance with the fourth exemplary, non-limiting embodiment of the stabilizer system 1 shown in figure 4A, the first water inlet unit 13 is provided with one water inlet opening 14.

[0094] The first water inlet unit 13 is provided with a first pump 15 that is arranged in fluid communication with the first water inlet opening 14. The first pump 15 will be required when the ship 30 is stationary in a body of water as in this operational mode of the ship it is not possible that water is scooped from the body of water by the water inlet opening 14. The pump 15 can also enhance a velocity of water that is sucked into the first water inlet unit 13 of the water flow generation system 4. The pump 15 can also be used when a ship is moving through a body of water in the event that scooping of water from the body of water is insufficient for supplying enough water to the water flow generation system 4.

[0095] As shown in figure 4A, the first pump 15 is arranged downstream from the first water inlet opening 14 in the first water inlet unit 13. The first pump 15 can be driven in any suitable way, for example electrically, hydraulically, pneumatically. The first pump 15 can also be coupled to a main engine of the ship. The stabilizer system 1 according to the invention can comprise multiple pumps for example to improve the redundancy and therefore the reliability of the stabilizer system.

[0096] The water flow generation system 4 comprises a first water outlet unit 10 that is provided with a plurality of water outlet openings 16. The number of water outlet openings 16 shown in figure 4A is exemplary in nature only and can be any suitable number, e.g. 1 , 2, 3, 4, 5, 10, 20 etc. For each of the water outlet openings 16 holds that they can have any suitable shape, e.g. circular, square, rectangular. It is not required that all water outlet openings 16 have the same shape or size. The arrangement of the water outlet openings 16 is also exemplary in nature only and can be any suitable arrangement.

[0097] The water flow generation system 4 comprises a first water channel 17 that is arranged in fluid communication with the first water inlet unit 13 and the first water outlet unit 10. In accordance with the fourth exemplary, non-limiting embodiment of the stabilizer system 1 shown in figure 4A, the first water channel 17 has a constant cross-section and is provided with a filter element 18, a water flow improvement unit 19, and a sensor 20. The filter element 18 is configured and arranged to prevent blockage of the first water channel 17 by for example at least one of fish, pieces of wood, plastic, and stones when water is sucked in close to the bottom underneath the body of water. The water flow improvement unit 19 can be configured to convert the water flow from a turbulent water flow into a laminar water flow. The sensor 20 can for example be a temperature sensor, a flow sensor, or a pressure sensor.

[0098] The water flow generation system 4 is configured to provide an artificially generated water flow on the basis of a first set of control signals from the plurality of control signals provided by the sensing and control system 3, and is arranged relative to the first stabilizing element 2 to allow the artificially generated water flow to be directed transverse to the first rotation axis 5 of the first stabilizing element 2. Figure 4A schematically illustrates that the artificially generated water flow is directed perpendicular to the first rotation axis 5. Although in this case the generated stabilizing force is maximal, the stabilizer system 1 according to the present invention can generate a useful stabilizing force as long as the artificially generated water flow is directed transverse to the first rotating axis 5. In the context of this application, the artificially generated water flow is considered to be directed transverse to the first rotation axis 5 if an acute angle between flow lines of the artificially generated water flow and the first rotation axis 5 is at least 45°.

[0099] In accordance with the fourth exemplary, non-limiting embodiment of the stabilizer system 1 shown in figure 4A, the first stabilizing element 2 has a cylindrical shape and can be referred to as a rotor. A first end part of the first stabilizing element 2 is connected with the hull 31 of the ship 30 at a first location via a first connection unit 8 of the stabilizer system 1. A second en part of the first stabilizing element 2 is connected with the hull 31 of the ship 30 at a second location via a second connection unit 9 of the stabilizer system 1. The first connection unit 8 and the second connection unit 9 are associated with the sensing and control system 3, and can adjust the first distance D1 between the first rotation axis 5 and the longitudinal center line 7 of the ship 30 on the basis of a third set of control signals from the plurality of control signals provided by the sensing and control system 3.

[0100] The stabilizing element 2 that is in the retracted position can generate a stabilizing force both while the ship is stationary in a body of water and while the ship is moving through a body of water because of the artificially generated water flow that is directed transverse to the first rotation axis 5. In accordance with the fourth exemplary, non-limiting embodiment of the stabilizer system 1 shown in figure 4A, the first connection unit 8 and the second connection unit 9 have a telescopic arrangement that enables adjustment of the first distance D1.

[0101] Figure 4B shows a schematic cross-sectional view of the ship 30 comprising the fourth exemplary, non-limiting embodiment of the stabilizer system 1 shown in figure 4A, wherein the first stabilizing element 2 is in a second position with respect to the longitudinal center line 7 of the ship 30. Compared to figure 4A, the telescopic arrangements of the first connection unit 8 and the second connection unit 9 have been extended in a direction perpendicular to the longitudinal center line 7 to increase the distance between the first rotation axis 5 and the longitudinal center line 7. Hence, distance D2 shown in figure 4B is larger than distance D1 shown in figure 4A. By adjusting the distance between the first rotation axis 5 and the longitudinal center line 7, an appropriate moment arm relative to a central roll point of the ship can be provided.

[0102] Figure 4B shows a suitable location at the transom of the ship for arranging the first water inlet opening 14 of the first water inlet unit 13. In this case, the first pump 15 will be required also when the ship 30 is moving through a body of water because it is not possible that sufficient water is scooped from the body of water by the water inlet opening 14.

[0103] Figure 4C shows a schematic cross-sectional view of the ship 30 comprising the fourth exemplary, non-limiting embodiment of the stabilizer system 1 shown in figures 4A and 4B, wherein the first stabilizing element 2 is in a third position with respect to the longitudinal center line 7 of the ship 30. In the third position, the first rotation axis 5 of the first stabilizing element 2 is arranged at a non-zero angle with respect to the longitudinal center line 7 of the ship 30. As mentioned above, this is referred to as the extended position of the first stabilizing element 2. If the ship 30 is stationary in a body of water, e.g. if the ship is at anchor, and the first stabilizing element 2 is in the extended position shown in figure 4C, generation of a stabilizing force is only possible as a result of the artificially generated local water flow that is directed transverse to the first rotation axis 5 of the first stabilizing element 2. Despite the fact the if a ship is moving through a body of water, the first stabilizing element 2 is exposed to a natural water flow, the artificially generated water flow can improve the performance of the stabilizer system 1 because the amount of water that is directed transverse to the first rotation axis 5 of the first stabilizing element 2 is increased. Figure 4C schematically shows that compared to figures 4A and 4B, the first water outlet unit 10 has been displaced relative to the hull 31 of the ship 30. This has been done to ensure that the artificially generated water flow can remain directed transverse to the first rotation axis 5 of the first stabilizing element 2 that is in the extended position. In this way, the performance of the stabilizer system 1 can be guaranteed irrespective of whether the first stabilizing element 2 is in the extended position shown in figure 4C or in the retracted position shown in figures 4A and 4B.

[0104] Figure 5 shows a schematic cross-sectional view of a part of a ship 30 comprising a fifth exemplary, non-limiting embodiment of the stabilizer system 1 according to the invention, wherein the first stabilizing element 2 is in a fourth position with respect to the longitudinal center line 7 of the ship 30. In the fourth position, the first rotation axis 5 of the first stabilizing element 2 is arranged at a non-zero angle with respect to the longitudinal center line 7 of the ship 30. As mentioned above, this is referred to as the extended position of the first stabilizing element 2.

[0105] Figure 5 schematically shows that only one of the end parts of the first stabilizing element 2 is associated with the hull 31. The first water outlet unit 10 has been displaced relative to the hull 31 of the ship 30 to allow the artificially generated water flow to stay directed transverse to the first rotation axis 5 of the first stabilizing element 2 that is in the extended position. Each of the water outlet openings 16 of the first water outlet unit 10 shown in figure 5 is provided with a water flow adjustment element 11 that is arranged to allow fine-tuning of a direction of the artificially generated water flow. The water flow adjustment elements 11 can also be used to adjust the amount of water and therefore the flow rate of the artificially generated water flow that is ejected from the first water outlet unit 10.

[0106] Figures 6A-6K show schematic perspective views of exemplary, non-limiting embodiments of a first stabilizing element 2 of the stabilizer system 1 according to the invention.

[0107] Figure 6A schematically shows a cylindrical stabilizing element 2 that has a first section 12a, a second section 12b, and a third section 12c. The first section 12a has a first constant cross-section in a direction perpendicular to the first rotation axis 5, the second section 12b has a second constant cross-section in a direction perpendicular to the first rotation axis 5, and the third section 12c has a third constant cross-section in a direction perpendicular to the first rotation axis 5. The first constant cross-section has a first perimeter with a circular shape and a first size. The second constant crosssection has a second perimeter with a circular shape and a second size. The third constant cross-section has a third perimeter with a circular shape and a third size. The third size is smaller than the first size and the second size. The second size is smaller than the first size. In this way, the cylindrical stabilizing element can have a telescopic construction that allows adjustment of the length L1 of the stabilizing element 2 as seen in the direction of the first rotation axis 5.

[0108] Figure 6B schematically shows the cylindrical stabilizing element 2 shown in figure 6A in an extended state, i.e. the first section 12a, the second section 12b, and the third section 12c have been arranged with respect to each other to provide the stabilizing element 2 with a length L2 that is greater than the length L1 shown in figure 6A.

[0109] Figure 6C schematically shows a cylindrical stabilizing element 2 that has a first section 12a, a second section 12b, and a third section 12c. The first section 12a has a first constant cross-section in a direction perpendicular to the first rotation axis 5, the second section 12b has cross-sections in a direction perpendicular to the first rotation axis 5 with varying sizes along the first rotation axis 5, and the third section 12c has a third constant cross-section in a direction perpendicular to the first rotation axis 5, the first constant cross-section and the third constant cross-section being the same. In this way, the stabilizing element has an increased effective cross-section compared to the stabilizing element having three sections with the same constant cross-section in all three sections. It is also possible that the second section 12b is configured to allow dynamic adjustment of the sizes of the cross-sections along the first rotation axis 5. In this way, the effective cross-section of the first stabilizing element 2 that is exposed to the artificially generated water flow can dynamically be adjusted. This allows for dynamic tuning of for example the magnitude of the generated stabilizing force.

[0110] Figure 6D schematically shows a cylindrical stabilizing element 2 that has a crosssection in a direction perpendicular to the first rotation axis 5 with a polygonal shape, in this case an octagonal shape, and a constant size along the first rotation axis 5.

[0111] Figure 6E schematically shows a spherical stabilizing element 2 that has a constant diameter. It is also possible that the spherical stabilizing element 2 is configured to allow dynamic adjustment of the diameter. In this way, the effective cross-section of the first stabilizing element 2 that is exposed to the artificially generated water flow can dynamically be adjusted. This allows for dynamic tuning of for example the magnitude of the generated stabilizing force. Figure 6F schematically shows a cylindrical stabilizing element 2 that has a crosssection in a direction perpendicular to the first rotation axis 5 with an elliptical shape, and a constant size along the first rotation axis 5.

[0112] Figure 6G schematically shows a stabilizing element 2 that has an asymmetric fin shape, and figure 6H schematically shows a stabilizing element 2 that has a symmetric fin shape.

[0113] Figure 6I schematically shows a cylindrical stabilizing element 2 that has a crosssection in a direction perpendicular to the first rotation axis 5 with having a varying size along the first rotation axis 5 that results in an egg shape.

[0114] Figure 6J schematically shows a cylindrical stabilizing element 2 that has a crosssection in a direction perpendicular to the first rotation axis 5 with having a varying size along the first rotation axis 5 that results in a teardrop shape.

[0115] Figure 6K schematically shows a cylindrical stabilizing element 2 that has a crosssection in a direction perpendicular to the first rotation axis 5 with having a varying size along the first rotation axis 5 that results in a pill shape.

[0116] Figure 7A shows a schematic cross-sectional view of a ship 30 comprising a sixth exemplary, non-limiting embodiment of the stabilizer system 1 according to the invention. The stabilizer system 1 comprises a first stabilizing element 2 and a second stabilizing element 22 that are arranged at opposite sides of the hull 31. The stabilizer system 1 comprises a first pump 15 and a first water outlet unit 10 that is provided with a first water outlet opening 16 that is arranged to direct an artificially generated waterflow transverse to the first stabilizing element 2. The stabilizer system 1 comprises a second pump 25 and a second water outlet unit 20 that is provided with a second water outlet opening 26 that is arranged to direct an artificially generated waterflow transverse to the second stabilizing element 22. The first pump 15 and the second pump 25 are arranged inside a water reservoir 24 of the water flow generation unit 4. The first pump 15 and the second pump 25 allow water from the water reservoir 24 to enter the water flow generation system 4 and to be ejected via the first water outlet opening 16 and the second water outlet opening 26, respectively. The water reservoir 24 can be filled with water from a body of water the ship 30 is arranged in via a water inlet opening 40 that is arranged at the keel of the hull 31.

[0117] It is noted that the flow rate of the artificially generated water flow can be adjusted dynamically depending on the stabilizing force that is required for damping an unwanted motion that varies depending on the conditions of the ship 30 while it is arranged in a body of water, e.g. high waves due to strong wind. The water supply to the water flow generation system 4 typically is constant. In order to always have sufficient water available in the event of changing water flow requirements, i.e. to smooth out variations in water supply requirements, the water reservoir 24 can be used as a buffer.

[0118] Figure 7B shows a schematic cross-sectional view of a ship 30 comprising a seventh exemplary, non-limiting embodiment of the stabilizer system 1 according to the invention. The stabilizer system 1 comprises a first stabilizing element 2 and a second stabilizing element 22 that are arranged at opposite sides of the hull 31. The stabilizer system 1 comprises a first pump 15 that is connected with both and a first water outlet unit 10 that is provided with a first water outlet opening 16 that is arranged to direct an artificially generated waterflow transverse to the first stabilizing element 2, and a second water outlet unit 20 that is provided with a second water outlet opening 26 that is arranged to direct an artificially generated waterflow transverse to the second stabilizing element 22. The first pump 15 is arranged inside the water reservoir 24 of the water flow generation unit 4 to allow water from the water reservoir 24 to enter the water flow generation system 4 and to be ejected via the first water outlet opening 16 and the second water outlet opening 26, respectively.

[0119] The present invention can be summarized as relating to a stabilizer system 1 for damping an unwanted motion of a ship. The stabilizer system comprises a first stabilizing element 2 having a first rotation axis 5, a sensing and control system 3 for sensing motions of the ship, selecting an unwanted motion of the ship, and generating control signals on the basis of the selected unwanted motion. The stabilizer system comprises a water flow generation system 4 for providing an artificially generated water flow that is directed transverse to the first rotation axis. The stabilizer system comprising a drive system 6 for rotating the first stabilizing element around the first rotation axis thereby generating a stabilizing force for damping the selected unwanted motion. The invention also relates to a ship 30 comprising the stabilizer system, and to a method of damping an unwanted motion of a ship using the stabilizer system according to the invention.

[0120] It will be clear to a person skilled in the art that the scope of the present invention is not limited to the examples discussed in the foregoing but that several amendments and modifications thereof are possible without deviating from the scope of the present invention as defined by the attached claims. In particular, combinations of specific features of various aspects of the invention may be made. An aspect of the invention may be further advantageously enhanced by adding a feature that was described in relation to another aspect of the invention. While the present invention has been illustrated and described in detail in the figures and the description, such illustration and description are to be considered illustrative or exemplary only, and not restrictive.

[0121] The present invention is not limited to the disclosed embodiments. Variations to the disclosed embodiments can be understood and effected by a person skilled in the art in practicing the claimed invention, from a study of the figures, the description and the attached claims. In the claims, the word “comprising” does not exclude other steps or elements, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference numerals in the claims should not be construed as limiting the scope of the present invention.

Claims

CLAIMS1. A stabilizer system (1) for damping an unwanted motion of a ship if the ship is in use, the stabilizer system (1) comprising: a first stabilizing element (2) that, if the stabilizer system (1) is in use, is associated with a hull of a ship, and is in contact with a body of water in which the ship is arranged, the first stabilizing element (2) having a first rotation axis (5); a sensing and control system (3) that, if the stabilizer system (1) is in use, is associated with the ship, the sensing and control system (3) being configured and arranged to sense motions of the ship, select an unwanted motion of the ship from the motions of the ship being sensed, and generate a plurality of control signals on the basis of the selected unwanted motion of the ship; a water flow generation system (4) that, if the stabilizer system (1) is in use, is associated with the ship and with the sensing and control system (3), the water flow generation system (4) being configured to provide an artificially generated water flow on the basis of a first set of control signals from the plurality of control signals, and being arranged relative to the first stabilizing element (2) to allow the artificially generated water flow to be directed transverse to the first rotation axis (5) of the first stabilizing element (2); and a drive system (6) that, if the stabilizer system (1) is in use, is associated with the ship, the first stabilizing element (2), and the sensing and control system (3), wherein the drive system (6) is configured and arranged to rotate the first stabilizing element (2) around the first rotation axis (5) on the basis of a second set of control signals from the plurality of control signals to allow that the first stabilizing element (2), which is exposed to the artificially generated water flow, enables generation of a stabilizing force for damping the selected unwanted motion of the ship.

2. The stabilizer system (1) according to claim 1, wherein the first rotation axis (5) of the first stabilizing element (2), if the stabilizer system (1) is in use, is arranged parallel to a longitudinal center line of the ship.

3. The stabilizer system (1) according to claim 2, wherein the first stabilizing element (2), if the stabilizer system (1) is in use, is associated with the hull of the ship at a firstlocation and at a second location, the first rotation axis (5) of the first stabilizing element (2) and the longitudinal center line of the ship being arranged at a first distance from each other as seen in a direction transverse to the first rotation axis (5) and the longitudinal center line.

4. The stabilizer system (1) according to claim 3, comprising a first connection unit (8) and a second connection unit (9), wherein the first stabilizing element (2), if the stabilizer system (1) is in use, is connected with the hull of the ship at the first location via the first connection unit (8), and at the second location via the second connection unit (9), the first connection unit (8) and the second connection unit (9) being associated with the sensing and control system (3), and being configured and arranged to allow adjustment of the first distance between the first rotation axis (5) and the longitudinal center line of the ship on the basis of a third set of control signals from the plurality of control signals provided by the sensing and control system (3).

5. The stabilizer system (1) according to claim 1, wherein the first rotation axis (5) of the first stabilizing element (2), if the stabilizer system (1) is in use, is arranged at a non-zero angle relative to a longitudinal center line of the ship.

6. The stabilizer system (1) according to claim 5, wherein the water flow generation system (4) comprises a first water outlet unit (10) that is associated with the sensing and control system (3), the first water outlet unit (10) is provided with a first water outlet opening (16), and the first water outlet unit (10) is configured and arranged to: be at least partially displaceable relative to the hull of the ship, if the stabilizer system (1) is in use, to allow, depending on the non-zero angle at which the first rotation axis (5) of the first stabilizing element (2) is arranged relative to the longitudinal center line of the ship, arrangement of the first water outlet unit (10) relative to the first stabilizing element (2) on the basis of a fourth set of control signals from the plurality of control signals for allowing the artificially generated water flow to be directed transverse to the first rotation axis (5); and / or comprise a first water flow adjustment element (11) that is arranged in the first water outlet opening (16), the first water flow adjustment element (11) being configured and arranged to allow, if the stabilizer system (1) is in use and depending on the non-zero angle at which the first rotation axis (5) is arranged relative to the longitudinal center line of the ship, adjustment of a direction of theartificially generated water flow on the basis of a fifth set of control signals from the plurality of control signals for allowing the artificially generated water flow to be directed transverse to the first rotation axis (5).

7. The stabilizer system (1) according to any one of the claims 1 to 6, wherein the first stabilizing element (2) has a cylindrical shape or a spherical shape, and wherein the drive system (6) is configured to allow rotation of the first stabilizing element (2), if the stabilizer system (1) is in use, fully around the first rotation axis (5).

8. The stabilizer system (1) according to any one of the claims 1 to 6, wherein the first stabilizing element (2) has a fin shape, and the drive system (6) is configured to allow rotation of the first stabilizing element (2), if the stabilizer system (1) is in use, around the first rotation axis (5) over a first rotation angle that is smaller than 360°, wherein rotation over the first rotation angle enables arranging the first stabilizing element (2) in a first position relative to the water flow generation system (4) to allow generation of the stabilizing force, and wherein the first rotation angle is adjustable on the basis of the second set of control signals provided by the sensing and control system (3) to allow adjustment of the first position and thereby of the stabilizing force.

9. The stabilizer system (1) according to claim 7 or 8, wherein the first stabilizing element (2) has a first cross-section in a direction perpendicular to the first rotation axis (5), the first cross-section having a first perimeter that has a first size, wherein the first stabilizing element (2) is configured to allow adjustment of the first size of the first perimeter.

10. The stabilizer system (1) according to claim 7, wherein in the event that the first stabilizing element (2) has the cylindrical shape, the first stabilizing element (2) has a second cross-section in a direction perpendicular to the first rotation axis (5), the second cross-section having a second perimeter that has a circular shape, an elliptical shape or a polygonal shape.

11. The stabilizer system (1) according to claim 7, wherein in the event that the first stabilizing element (2) has the cylindrical shape, the first stabilizing element (2) has:a third cross-section in a direction perpendicular to the first rotation axis (5), the third cross-section having a third perimeter that has a third size; and a fourth cross-section in the direction perpendicular to the first rotation axis (5), the fourth cross-section having a fourth perimeter that has a fourth size, wherein the third size of the third perimeter and the fourth size of the fourth perimeter are different.

12. The stabilizer system (1) according to claim 8, wherein in the event that the first stabilizing element (2) has the fin shape, the first stabilizing element (2) has: a fifth cross-section in a direction perpendicular to the first rotation axis (5), the fifth cross-section having a fifth perimeter that has a fifth size; and a sixth cross-section in the direction perpendicular to the first rotation axis (5), the sixth cross-section having a sixth perimeter that has a sixth size, wherein the fifth size of the fifth perimeter and the sixth size of the sixth perimeter are different.

13. The stabilizer system (1) according to any one of the claims 1 to 12, wherein the first stabilizing element (2) has a first length, L1 , in a direction of the first rotation axis (5), the first stabilizing element (2) being configured to allow adjustment of the first length, L1.

14. The stabilizer system (1) according to any one of the claims 1 to 13, wherein the water flow generation system (4) comprises a first water inlet unit (13) that is provided with a first water inlet opening (14) that is configured and arranged to allow, if the stabilizer system (1) is in use, entrance into the water flow generation system (4) of water from a body of water in which the ship is arranged.

15. The stabilizer system (1) according to claim 14, wherein the first water inlet unit (13) is provided with a first pump (15) that is arranged in fluid communication with the first water inlet opening (14).

16. The stabilizer system (1) according to claim 15, wherein the water flow generation system (4) comprises a water reservoir (24) that is arranged inside the hull of the ship, and wherein the first pump (15) is configured and arranged to allow, if the stabilizersystem (1) is in use, entrance into the water flow generation system (4) of water from the water reservoir (24).

17. The stabilizer system (1) according to any one of the claims 14 to 16, wherein the water flow generation system (4) comprises a first water channel (17) that is arranged in fluid communication with the first water inlet unit (13) and the first water outlet unit (10).

18. The stabilizer system (1) according to claim 17, wherein the first water channel (17) is provided with at least one of a filter element (18), a water flow improvement unit (19), and a sensor (20).

19. A ship (30) comprising a stabilizer system (1) according to any one of the claims 1 to 18.

20. A method of damping an unwanted motion of a ship if the ship is in use, the method comprising: providing a stabilizer system (1) comprising:• a first stabilizing element (2) that is associated with a hull of a ship, and is in contact with a body of water in which the ship is arranged, the first stabilizing element (2) having a first rotation axis (5);• a sensing and control system (3) that is associated with the ship;• a water flow generation system (4) that is associated with the ship and with the sensing and control system (3); and• a drive system (6) that is associated with the ship, the first stabilizing element (2), and the sensing and control system (3); activating the sensing and control system (3) to:• sense motions of the ship;• select an unwanted motion of the ship from the motions of the ship being sensed;• generate a plurality of control signals on the basis of the selected unwanted motion of the ship; activating the water flow generation system (4) to provide an artificially generated water flow on the basis of a first set of control signals of the plurality of controlsignals, and to direct the artificially generated water flow transverse to the first rotation axis (5) of the first stabilizing element (2); and activating the drive system (6) to rotate the first stabilizing element (2) around the first rotation axis (5) on the basis of a second set of control signals from the plurality of control signals to allow the first stabilizing element (2), which is exposed to the artificially generated water flow, to generate a stabilizing force for damping the selected unwanted motion of the ship.

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