FR3143541A3 - Marine propulsion system for pitch reduction - Google Patents

Abstract

The invention relates to a maritime propulsion system (1), comprising: - first and second immersion hulls (3, 4) extending in a longitudinal direction (X) and offset relative to each other , a connecting structure (2) joining the shells (3, 4) and an emerged element (5); -the first hull and the second immersion hull (3, 4) each comprising first and second thrusters (31, 32) offset longitudinally relative to each other, the first thruster being a cycloidal thruster configured to present a variable and adjustable propulsion direction around the transverse direction (Y); -a device (7) for determining the attitude of the hulls (3, 4); -a processing device (7), configured to control the direction of propulsion of the first thruster (31) of the first and second immersion hulls (3, 4) as a function of the attitude determined so as to regulate the angle of the first and second shells (3, 4) around the transverse direction (Y). Figure to be published with the abstract: Fig. 1

Description

Marine propulsion system for pitch reduction

The invention relates to maritime propulsion systems, in particular maritime propulsion systems having to move a submerged load.

In order to reduce the consumption linked to the movement of a maritime vessel, a known solution proposes two hulls submerged at a standstill and offset from each other in a transverse direction. The hulls ensure the flotation of an emerged load. A connection connects the hulls to an emerged support, on which the load is positioned.

Such a configuration generally makes it possible to reduce the flotation surface in order to reduce the vessel's consumption. However, it turns out that such a vessel has performances and in particular consumption that are very sensitive to variations in centering, and in particular to movements of the payload. Furthermore, there is a need to further reduce the fuel consumption of such a vessel.

The invention aims to solve one or more of these drawbacks. The invention thus relates to a maritime propulsion system, comprising:
-at least first and second immersion shells extending in a longitudinal direction and offset from each other in a transverse direction, at least one connecting structure securing the first and second immersion shells and intended to secure an emerged element to the first and second immersion shells;
-the first hull and the second immersion hull each comprising first and second thrusters longitudinally offset relative to each other and configured to propel said first and second immersion hulls, the first thruster being a cycloidal thruster configured to have a variable and adjustable propulsion direction about the transverse direction;
- a device for determining the attitude of the first and second immersion hulls;
-a processing device, configured to control the propulsion direction of the first thruster of the first and second immersion hulls according to the determined attitude so as to regulate the angle of the first and second hulls about the transverse direction.

The invention also relates to the following variants. Those skilled in the art will understand that each of the features of the following variants can be independently combined with the above features, without constituting an intermediate generalization.

According to a variant, said first thruster is a cycloidal thruster provided with blades pivoting around the transverse direction.

According to yet another variant, the first thruster is positioned at the front part of its respective hull.

According to another variant, the second thruster of the first and second hulls is a cycloidal thruster configured to have a variable and adjustable propulsion direction about the transverse direction.

According to yet another variant, the processing device is configured to control the propulsion direction of the second thruster of the first and second hulls so as to define their immersion depth.

According to another variant, the processing device is configured to control the propulsion direction of the first and second thrusters of the first and second immersion hulls according to the determined attitude so as to regulate the angle of the first and second hulls about the longitudinal direction.

According to yet another variation, the processing device is configured to control the propulsion direction of the first thruster both when the marine propulsion system is moving in the longitudinal direction and when the marine propulsion system is stationary in the longitudinal direction.

According to one variant, the processing device is configured to implement a predictive pitch correction based on the determined attitude.

According to another variant, one of said shells comprises hollow and partitioned volumes in different positions in the longitudinal direction, the processing device is configured to control the transfer of a fluid between hollow volumes according to a slow loop regulation of the angle of the first and second shells around the transverse direction, depending on the determined attitude.

The invention also relates to a vessel including a maritime propulsion system as defined above and an emerged pilot station secured to the connecting structure.

Other characteristics and advantages of the invention will emerge clearly from the description given below, for information purposes only and in no way limiting, with reference to the appended drawings, in which:

is a perspective view of a marine propulsion system according to an exemplary embodiment of the invention;

is a front sectional view of the marine propulsion system of the ;

is a perspective view of the interior of a submerged hull of the maritime propulsion system according to the invention;

is a perspective view of the interior of the submerged hull of the with an example of pitch control;

is a perspective view of two submerged hulls with examples of control to correct rolling;

is a perspective view of a vessel equipped with a maritime propulsion system according to the invention.

There is a perspective view of a marine propulsion system 1 according to an exemplary embodiment of the invention. The marine propulsion system 1 comprises in particular first and second immersion hulls 3 and 4, and a connecting structure 2.

The immersion hulls 3 and 4 are intended to be submerged and to be secured to an emerged element 5. The immersion hulls 3 and 4 are intended to ensure the flotation of the maritime propulsion system 1 associated with the emerged element 5. The immersion hulls 3 and 4 thus delimit in a manner known per se an interior volume filled with an element having a density lower than water, typically air. The immersion hulls 3 and 4 extend in a longitudinal direction X, corresponding to the main direction of movement of the maritime propulsion system 1. The immersion hulls 3 and 4 are offset relative to each other in a transverse direction Y. Such a configuration makes it possible both to optimize the flotation, the stability in the face of rolling of the maritime propulsion system 1 and to reduce the surface of water displaced during the movement of the system 1. Such a configuration also makes it possible to keep the emerged element 5 completely out of the water to limit the resistance to advancement.

The maritime propulsion system 1 also comprises a connecting structure 2 configured to secure the immersion hulls 3 and 4 and intended to secure these immersion hulls 3 and 4 to the emerged element 5. The connecting structure 2 makes it possible in particular to maintain a spacing in the transverse direction Y between the immersion hulls 3 and 4. The connecting structure 2 advantageously makes it possible to keep these immersion hulls 3 and 4 substantially parallel. The connecting structure 2 is here in the form of beams 21 to 24 extending vertically from the immersion hulls 3 and 4. These beams 21 to 24 are here in the form of hollow and profiled boxes. The beams 21 and 23 extend vertically from the hull 3, respectively from a front end and from a rear end of the hull 3. The beams 22 and 24 extend vertically from the hull 4, respectively from a front end and from a rear end of the hull 4. The beams 21 to 24 are thus intended to extend from the hulls 3 and 4 in immersion to the emerged element 5 to maintain the latter above the surface of the water, as illustrated in FIG. : the surface of the water here corresponds to line 8. The lower part of the emerged element 5 here belongs to the connecting structure 2, ensuring the mechanical connection between the beams 21 to 24. The emerged element 5 is intended to receive different loads or arrangements out of the water, for example a passenger reception platform, control systems or any other useful arrangements.

The hull 3 and the hull 4 are provided with thrusters 31 and 32, and 41 and 42, respectively. The thrusters 31 and 32 are offset longitudinally relative to each other. The thruster 31 is here positioned at a front end of the hull 3 and the thruster 32 is here positioned at a rear end of the hull 3. The thrusters 41 and 42 are offset longitudinally relative to each other. The thruster 41 is here positioned at a front end of the hull 4 and the thruster 42 is here positioned at a rear end of the hull 4. The thrusters 31, 32, 41 and 42 are configured to propel the immersion hulls 3 and 4 in the longitudinal direction X. The thrusters 31, 32, 41 and 42 are cycloidal thrusters, also referred to by the Voith-Siemens term. The thrusters 31, 32, 41 and 42 thus comprise, in a manner known per se, blades driven by a gear system defining their orientation. The thrusters 31 and 41 (advantageously the thrusters positioned at the front) are configured to have a variable and adjustable propulsion direction around the transverse direction Y. Thus, even if the majority of the propulsion is intended to be carried out in the X direction, a variable propulsion component can be added in the Z direction. The orientation of the blades of the cycloidal thrusters 31 and 41 is thus configured to be adjustable, controlled by a control device schematically represented by the reference 7. The control device 7 is described here with different functions in this example, each of these functions being able to be entrusted to distinct devices located at different places in the system 1.

The blades of the propellers 31, 32, 41 and 42 project transversely relative to the hulls 3 and 4. The blades of the propellers 31, 32, 41 and 42 project into the intermediate space between the hulls 3 and 4, limiting the risks of damage by collision and reducing the lateral bulk of the maritime propulsion system 1.

The control device 7 is here also configured to determine the attitude of the hulls 3 and 4. The control device 7 can thus include or be connected to attitude sensors known per se, using for example gyroscopes or accelerometers. From the attitude determined for the hulls 3 and 4, the control device 7 can also act as a processing device and is configured to control the propulsion direction of the thrusters 31 and 41, so as to regulate the angle of the hulls 3 and 4 about the transverse direction Y, that is to say to control the pitch of the system 1. The control device 7 can thus define the propulsion component of the thrusters 31 and 41 according to the vertical direction Z. By thus regulating the attitude of the hulls 3 and 4, it is thus possible to keep them as close as possible to the horizontal and thus limit the drag of the hulls 3 and 4 to reduce fuel consumption. Such regulation also makes it possible to improve comfort for any passengers present on the emerged element 5. Such control of the vertical component of the propulsion at the level of the front part of the hulls 3 and 4 proves advantageous for controlling the pitching of the system 3.

The use of cycloidal type 31, 32, 41 and 42 propellers allows to obtain a very good efficiency compared to rotary propellers. Furthermore, the use of cycloidal type propellers for roll control allows to be much more reactive in the control, the dynamics of the change of direction of the propulsion being very fast.

Advantageously, the thrusters 32 and 42 are also configured to have a variable and adjustable propulsion direction around the transverse direction Y. The processing device 7 will then be configured to control the propulsion direction of the thrusters 32 and 42 so as to define the immersion depth of the hulls 3 and 4, or so as to provide more pitch control of the system 1. Such a configuration also makes it possible to provide redundancy of the pitch control.

In this configuration, the processing device 7 may also be configured to control the propulsion direction of the thrusters 31, 32, 41 and 42 of the immersion hulls 3 and 4 as a function of the determined attitude so as to regulate the angle of the first and second hulls around the longitudinal direction X and thus control the rolling of the system 1.

Advantageously, the processing device 7 can implement the control of the propulsion direction both when the maritime propulsion system 1 is moving in the longitudinal direction and when the system 1 is stationary in this direction. The processing device 7 can thus also implement the pitch control when the system 1 is at the dock.

Advantageously, the processing device 7 is configured to implement a predictive correction of the pitch and/or roll as a function of the determined attitude. As a function of the measured attitude and a knowledge base, the processing device 7 will be able to take control measures in anticipation of the attitude of the hulls 3 and 4.

There is a perspective view showing the interior of the hull 4 and the beams 22 and 24. The hull 4 can be used to house the mechanism and an electric motor for the thrusters 41 and 42. Power cables for the electric motors for the thrusters 41 and 42 can be housed in the beams 22 and 24, for connection to batteries or an alternator possibly secured to the emerged element 5. Furthermore, the hull 4 advantageously comprises different hollow and partitioned volumes, and a pumping system for passing a fluid from one hollow volume to another. By distributing the hollow volumes from front to back of the hull 4 and by moving a fluid between them, the trim of the hull 4 can be modified. Thus, the processing device 7 can take into account the determined attitude of the system 3, in order to correct the pitching according to a slow loop by acting on these ballast systems.

Hull 3 can of course have a configuration similar to that of hull 4.

There illustrates a first example of pitch control implemented at the level of the hull 4. In this example, if the determined attitude corresponds to a forward pivoting of the hull 4, the regulation principle will be able to apply an upward vertical component on the thruster 41 and a downward vertical component on the thruster 42 (dotted arrows). If the determined attitude corresponds to a rearward pivoting of the hull 4, the regulation principle will be able to apply a downward vertical component on the thruster 41 and an upward vertical component on the thruster 42 (solid arrows). A similar control is applied to the hull 3.

There illustrates an example of roll control implemented at the system level 1. This control can be carried out simultaneously with pitch control, by modulating the components of the different vertical propulsions. In this example, if the determined attitude corresponds to a sinking of the hull 4 relative to the hull 3, the regulation principle can apply an upward vertical component to the thrusters 41 and 42, and a downward vertical component to the thrusters 31 and 32 (dotted arrows). If the determined attitude corresponds to a sinking of the hull 3 relative to the hull 4, the regulation principle can apply a downward vertical component to the thrusters 41 and 42, and an upward vertical component to the thrusters 31 and 32 (solid arrows).

There illustrates an example of a ship 9 including the maritime propulsion system 1. In this example, a raised cockpit 91 is provided integrally with the connecting structure 2 and the raised element 5, here forming a floor for receiving passengers and facilities.

According to another variant, the maritime propulsion system 1 can be attached to a flying structure to form a floating drone, or to a transport pod to carry out troop transport.

Claims (10)

Marine propulsion system (1), characterized in that it comprises:
-at least first and second immersion shells (3, 4) extending in a longitudinal direction (X) and offset relative to each other in a transverse direction (Y), at least one connecting structure (2) securing the first and second immersion shells (3, 4) and intended to secure an emerged element (5) to the first and second immersion shells (3, 4);
-the first hull and the second immersion hull (3, 4) each comprising first and second thrusters (31, 32) longitudinally offset relative to each other and configured to propel said first and second immersion hulls, the first thruster being a cycloidal thruster configured to have a variable and adjustable propulsion direction around the transverse direction (Y);
- a device (7) for determining the attitude of the first and second immersion hulls (3, 4);
-a processing device (7), configured to control the propulsion direction of the first thruster (31) of the first and second immersion hulls (3, 4) as a function of the determined attitude so as to regulate the angle of the first and second hulls (3, 4) around the transverse direction (Y). A marine propulsion system (1) according to claim 1, wherein said first thruster (31) is a cycloidal thruster provided with blades pivoting about the transverse direction. A marine propulsion system (1) according to claim 1 or 2, wherein the first thruster (31) is positioned at the forward portion of its respective hull. A marine propulsion system (1) according to any preceding claim, wherein:
-the second thruster (32) of the first and second hulls (3, 4) is a cycloidal thruster configured to have a variable and adjustable propulsion direction around the transverse direction (Y). Marine propulsion system (1) according to claim 5, wherein the processing device (7) is configured to control the propulsion direction of the second thruster (32) of the first and second hulls (3, 4) so as to define their immersion depth. A marine propulsion system (1) according to any preceding claim, wherein the processing device (7) is configured to control the propulsion direction of the first and second thrusters of the first and second immersion hulls (3, 4) as a function of the determined attitude so as to regulate the angle of the first and second hulls (3, 4) about the longitudinal direction (X). A marine propulsion system (1) according to any preceding claim, wherein the processing device (7) is configured to control the propulsion direction of the first thruster (31) both when the marine propulsion system is moving in the longitudinal direction (X) and when the marine propulsion system is stationary in the longitudinal direction. Maritime propulsion system (1) according to any one of the preceding claims, wherein the processing device (7) is configured to implement a predictive pitch correction as a function of the determined attitude. Marine propulsion system (1) according to any one of the preceding claims, wherein one of said hulls comprises hollow and partitioned volumes in different positions in the longitudinal direction, the processing device (7) is configured to control the transfer of a fluid between hollow volumes according to a slow loop regulation of the angle of the first and second hulls (3, 4) around the transverse direction (Y), depending on the determined attitude. Vessel (9) including a maritime propulsion system (1) according to any one of the preceding claims and an emerged pilot station (91) integral with the connecting structure (2).