Stabilized floating platform
A floating structure is floatable in a body of liquid and stabilized with respect to at least one of roll and pitch. Such a structure includes: a hull including compartments, each compartment being open at the bottom thereof relative to a horizontal plane, and being adapted to accommodate ingress by the body of liquid; a negative pressure source to negatively pressure a volume above a level of the liquid in at least one of the compartments; and one or more arrangements by which at least one or more other of the compartments can be made to exhibit a positive buoyancy.
This application claims the priority of U.S. Patent Application No. 60/663,736, filed on Mar. 22, 2005, the disclosure of which is incorporated herein in its entirety by reference.
BACKGROUNDTypical floating platforms acquire their floatation forces by directly displacing the water with their hulls. A pneumatic floating platform utilizes indirect displacement, in which the platform rests on trapped air that displaces the water. The primary buoyancy force is provided by air pressure acting on the underside of the deck.
A pneumatically stabilized platform (PSP) is a type of pneumatic platform that includes cylindrically shaped cells packed together in a rectangular pattern to form a module. Each cylinder is sealed at the top, open to the ocean at its base, and contains air at a pressure slightly above atmospheric pressure.
As needed, air is allowed to flow from a cylinder to its neighbors through a manifold or connecting orifices. The airflow provides a mechanism to help reduce the peaks in the pressure distribution beneath the structure and provide platform stability as well as a mechanism for dissipating wave energy.
An assembly of cylinders results in enclosed interstitial regions between cylinders, which may be filled with air, foam or other material. These regions are isolated from the air pockets within the cylinders to provide additional buoyancy and righting moment. As long as design loads are not exceeded, this feature can enable the PSP to endure catastrophic air pressure loss. The distribution of the flotation force in a PSP can be modified as needed to minimize the hogging moment or in response to large concentrated loads on the deck. Further, it is possible, for a given sea state, to tune the oscillation of the water columns inside the cylinders to minimize the overall hydrodynamic loading to which the platform is subjected.
SUMMARYAn embodiment of the present invention provides a floating structure floatable in a body of liquid and stabilized with respect to at least one of roll and pitch. Such a structure can include: a hull including compartments, each compartment being open at the bottom thereof relative to a horizontal plane, and being adapted to accommodate ingress by the body of liquid; a negative pressure source to negatively pressure a volume above a level of the liquid in at least one of the compartments; and one or more arrangements by which at least one or more other of the compartments can be made to exhibit a positive buoyancy.
An embodiment of the present invention provides a floating structure floatable in a body of liquid and stabilized with respect to at least one of roll and pitch. Such a structure can include: a hull including a plurality of compartments, each compartment being open at the bottom thereof relative to a horizontal plane, and being adapted to accommodate ingress by the body of liquid; a negative pressure source to induce a negative buoyancy, relative to a net positive buoyancy of the structure as a whole, in at least one of the compartments; and one or more arrangements by which at least one or more other of the compartments can be made to exhibit a positive buoyancy, relative to the net positive buoyancy of the structure as a whole.
An embodiment of the present invention provides a method of stabilizing, with respect to at least one of roll and pitch, a structure that floats in a body of liquid, the method comprising: providing a hull; configuring the hull to include a plurality of compartments, each compartment being open at the bottom thereof relative to a horizontal plane, and being adapted to accommodate ingress by the body of liquid; negatively pressuring a volume above a level of the liquid in at least one of the compartments; and inducing a positive buoyancy in at least one other of the compartments.
An embodiment of the present invention provides a method of stabilizing, with respect to at least one of roll and pitch, a structure that floats in a body of liquid, the method comprising: providing a hull; configuring the hull to include a plurality of compartments, each compartment being open at the bottom thereof relative to a horizontal plane, and being adapted to accommodate ingress by the body of liquid; inducing a negative buoyancy, relative to a net positive buoyancy of the structure as a whole, in at least one of the compartments; and inducing a positive buoyancy, relative to the net positive buoyancy of the structure as a whole, in at least one other of the compartments.
Additional features and advantages of the present invention will be more fully apparent from the following detailed description of example embodiments, the accompanying drawings and the associated claims.
BRIEF DESCRIPTION OF DRAWINGSThe accompanying drawings are intended to depict example embodiments of the present invention and should not be interpreted to limit the scope thereof. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted.
The accompanying drawings are intended to depict example embodiments of the present invention and should not be interpreted to limit the scope thereof. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted.
DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTSIt will be understood that if an element or layer is referred to as being “on,” “against,” “connected to” or “coupled to” another element or layer, then it can be directly on, against connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, if an element is referred to as being “directly on”, “directly connected to” or “directly coupled to” another element or layer, then there are no intervening elements or layers present. Like numbers refer to like elements throughout. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Spatially relative terms, such as “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, term such as “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
Although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections, it should be understood that these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are used only to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “includes” and/or “including”, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
In
In
In
Operation of the stabilized floating platform of
Relative to an overall buoyancy of the stabilized floating structure 100, each negatively-pressured 110N compartment 106 represents a negative buoyancy contribution to the overall buoyancy. Depending upon the number of such negatively-pressurized 110N compartments 106, their proportions and the magnitude of the negative pressure applied to them, they collectively could make the overall buoyancy of the stabilized platform 100 negative, causing the platform 100 to sink. To counterbalance the negative buoyancy of the negatively-pressurized 110N compartments 106, one or more positively-pressurized 110P compartments 106 are provided, each of which represents a respective positive buoyancy contribution to the overall buoyancy. Alternatively, other arrangements for introducing positive buoyancy (e.g., sealed compartments filled with a gas such as air, compartments that may or may not be sealed and that are filled with foam, etc.) could be used instead of, or in addition to, the respectively positively-pressurized 110P compartments 106.
In
Also, for simplicity of illustration in
Further as to
The stabilized floating platform 300 has many similarities with respect to
Other such pitch/roll inducing loads are contemplated. For example, consider the load as being a ramp (not shown) from one side of the floating platform 304 to a dock (not shown) in a circumstance in which the floating platform 300 is a ferry. Such a ferry 300 would make use of the matrix of compartments 106′ to stabilize against pitch and/or roll while at the dock while loading/offloading vehicles, etc. In contrast, while the ferry 300 is under way (or, in other words, not loading/offloading at the dock, then pressurization of the matrix of compartments 106 could be disabled, or each of the compartments 106′ could be sealed by closing a lid thereof so as to reduce drag.
Furthermore, in the circumstance of
With some example embodiments of the present invention having thus been described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications are intended to be included within the scope of the present invention.
Claims
1. A floating structure floatable in a body of liquid and stabilized with respect to at least one of roll and pitch, the structure comprising:
- a hull including a plurality of compartments, each compartment being open at the bottom thereof relative to a horizontal plane, and being adapted to accommodate ingress by the body of liquid;
- a negative pressure source to negatively pressure a volume above a level of the liquid in at least one of the compartments; and
- one or more arrangements by which at least one or more other of the compartments can be made to exhibit a positive buoyancy.
2. The structure of claim 1, wherein the at least one of the one or more arrangements includes:
- a positive pressure source to positively pressure a volume above the level of the liquid in at least one other of the compartments.
3. The structure of claim 1, wherein:
- an overall buoyancy of the structure is positive;
- the at-least-one negatively pressurized compartment represents respective negative buoyancy contributions to the overall buoyancy; and
- the one or more arrangements represents respective positive buoyancy contributions to the overall buoyancy.
4. The structure of claim 1, wherein:
- the plurality of compartments, from a top view, is arranged as a matrix.
5. The structure of claim 4, wherein:
- the plurality of compartments includes multiple respectively negatively-pressurized compartments and multiple compartments made to exhibit respective positive buoyancy by the one or more arrangements, respectively; and
- the matrix is arranged so that the negatively-pressurized compartments are distributed relatively more towards the periphery of the matrix and compartments exhibiting respective positive buoyancy are distributed relatively more towards a central region of the matrix.
6. The structure of claim 5, wherein:
- the matrix is rectangular; and
- respectively negatively-pressurized compartments are located at corner positions of the matrix.
7. The structure of claim 1, further comprising:
- a deck on the hull;
- wherein a load is disposed towards one side of the deck so as to induce a first roll moment;
- wherein the plurality of compartments includes multiple respectively negatively-pressurized compartments and multiple compartments made to exhibit respective positive buoyancy by the one or more arrangements, respectively; and
- wherein the matrix is arranged so that the respectively negatively-pressurized compartments are distributed relatively more towards a side of the matrix opposite the load so as to induce a second roll moment that opposes the first roll moment.
8. The structure of claim 7, wherein the load is one of the following:
- a crane that disposes another load aside the structure; and
- a ramp to another structure in a circumstance in which the floating platform is a ferry and a vehicle is located on at least one of the ramp and the area on the deck near the ramp.
9. The structure of claim 1, wherein each compartment is one of:
- a prism, a bottom end of which is fictional; and
- a cylinder, a bottom end of which is fictional.
10. A floating structure floatable in a body of liquid and stabilized with respect to at least one of roll and pitch, the structure comprising:
- a hull including a plurality of compartments, each compartment being open at the bottom thereof relative to a horizontal plane, and being adapted to accommodate ingress by the body of liquid;
- a negative pressure source to induce a negative buoyancy, relative to a net positive buoyancy of the structure as a whole, in at least one of the compartments; and
- one or more arrangements by which at least one or more other of the compartments can be made to exhibit a positive buoyancy, relative to the net positive buoyancy of the structure as a whole.
11. The floating structure of claim 10, wherein the at least one of the one or more arrangements includes:
- a positive pressure source to induce a respective positive buoyancy in at least one other of the compartments.
12. A method of stabilizing, with respect to at least one of roll and pitch, a structure that floats in a body of liquid, the method comprising:
- providing a hull;
- configuring the hull to include a plurality of compartments, each compartment being open at the bottom thereof relative to a horizontal plane, and being adapted to accommodate ingress by the body of liquid;
- negatively pressuring a volume above a level of the liquid in at least one of the compartments; and
- inducing a positive buoyancy in at least one other of the compartments.
13. The method of claim 12, wherein the step of inducing includes:
- positively pressuring a volume above a level of the liquid in at least one of the other compartments.
14. The method of claim 12, wherein method further comprises:
- arranging the plurality of compartments, from a top view, as a matrix.
15. The method of claim 14, wherein:
- the plurality of compartments includes multiple respectively negatively-pressurized compartments and multiple compartments made to exhibit respective positive buoyancy; and
- the method further includes the following, distributing the respectively negatively-pressurized compartments in the matrix relatively more towards the periphery of the matrix, and distributing the respectively positively-buoyant compartments in the matrix relatively more towards a central region of the matrix.
16. The method of claim 14, wherein:
- the matrix is rectangular; and
- the method further comprises the following, disposing respectively negatively-pressurized compartments at corner positions of the matrix.
17. The method of claim 12, further comprising:
- providing a deck on the hull;
- disposing a load towards one side of the deck so as to induce a first roll moment;.
- wherein the plurality of compartments includes multiple respectively negatively-pressurized compartments and multiple compartments made to exhibit respective positive buoyancy; and
- distributing the respectively negatively-pressurized compartments relatively more towards a side of the matrix opposite the load so as to induce a second roll moment that opposes the first roll moment.
18. The method of claim 12, wherein the configuring step configures each compartment as one of:
- a prism, a bottom end of which is fictional; and
- a cylinder, a bottom end of which is fictional.
19. A method of stabilizing, with respect to at least one of roll and pitch, a structure that floats in a body of liquid, the method comprising:
- providing a hull;
- configuring the hull to include a plurality of compartments, each compartment being open at the bottom thereof relative to a horizontal plane, and being adapted to accommodate ingress by the body of liquid;
- inducing a negative buoyancy, relative to a net positive buoyancy of the structure as a whole, in at least one of the compartments; and
- inducing a positive buoyancy, relative to the net positive buoyancy of the structure as a whole, in at least one other of the compartments.
20. The method of claim 19, wherein the step of inducing includes:
- positively pressuring a volume above a level of the liquid in at least one of the other compartments.
Type: Application
Filed: Mar 22, 2006
Publication Date: Oct 12, 2006
Inventors: Yong Cho (Silver Spring, MD), Philip Kim (Adelphi, MD)
Application Number: 11/386,097
International Classification: B63B 35/44 (20060101);