Motion absorbing system and method for a structure

Patent metadata

Field	Value
Publication number	US-11279452-B2
Application number	US-202117314201-A
Country	US
Kind code	B2
Filing date	May 7, 2021
Priority date	Nov 2, 2018
Publication date	Mar 22, 2022
Grant date	Mar 22, 2022

Abstract

A motion absorbing system and method for a structure includes the coupling of a container to a structure. The container has a liquid disposed therein wherein a ullage is defined above a surface of the liquid. An elastic element is positioned in the liquid. The elastic element has a natural frequency tuned to damp motion of the liquid.

First claim

The invention claimed is:

1. A motion absorbing system, comprising:
a structure adapted to float on a body of water;
a container coupled to said structure, said container having a liquid disposed therein wherein a ullage is defined above a surface of said liquid; and
an elastic element disposed in said liquid, said elastic element having a natural frequency tuned to damp motion of said liquid caused by water movement in the body of water acting on said structure;
wherein said elastic element comprises a tube having a closed end and an open end, said tube being fixedly positioned in said liquid, said tube having a piston of said liquid residing in said tube to seal said open end wherein a gas fills said tube between said piston and said closed end of said tube, said tube including a flow constrictor disposed therein such that said gas passes through said flow constrictor when said gas experiences compression and when said gas experiences expansion.

2. A motion absorbing system as in claim 1 , wherein said tube varies in diameter along the length thereof.

3. A motion absorbing system as in claim 2 , wherein a longitudinal axis of said tube is approximately perpendicular to said surface of said liquid.

4. A motion absorbing system as in claim 1 , wherein said elastic element is selected from the group consisting of a bellows disposed in said liquid and a balloon disposed in said liquid.

5. A motion absorbing system as in claim 1 , wherein said elastic element is coupled to said container.

6. A motion absorbing system as in claim 1 , wherein said container comprises a ballast tank of said structure.

7. A motion absorbing system for a structure, comprising:
a container adapted to be coupled to a structure, said container having a liquid disposed therein wherein a ullage is defined above a surface of said liquid; and
an elastic element disposed in said liquid, said elastic element having a natural frequency tuned to damp motion of said liquid;
wherein said elastic element comprises a tube having a closed end and an open end, said tube being fixedly positioned in said liquid, said tube having a piston of said liquid residing in said tube to seal said open end wherein a gas fills said tube between said piston and said closed end of said tube, said tube including a flow constrictor disposed therein such that said gas passes through said flow constrictor when said gas experiences compression and when said gas experiences expansion.

8. A motion absorbing system as in claim 7 , wherein said tube varies in diameter along the length thereof.

9. A motion absorbing system as in claim 7 , wherein a longitudinal axis of said tube is approximately perpendicular to said surface of said liquid.

10. A motion absorbing system as in claim 7 , wherein said elastic element is selected from the group consisting of a bellows disposed in said liquid and a balloon disposed in said liquid.

11. A motion absorbing system as in claim 7 , wherein said elastic element is coupled to said container.

12. A motion absorbing system as in claim 7 , wherein the structure floats on a body of water, and wherein said container comprises a ballast tank.

13. A motion absorbing system comprising a plurality of motion absorbers adapted to be coupled to a structure, each of said motion absorbers including
a container adapted to be coupled to structure, said container having a liquid disposed therein wherein a ullage is defined above a surface of said liquid; and
an elastic element disposed in said liquid, said elastic element having a natural frequency tuned to damp motion of said liquid;
wherein said elastic element comprises a tube having a closed end and an open end, said tube being fixedly positioned in said liquid, said tube having a piston of said liquid residing in said tube to seal said open end wherein a gas fills said tube between said piston and said closed end of said tube, said tube including a flow constrictor disposed therein such that said gas passes through said flow constrictor when said gas experiences compression and when said gas experiences expansion.

14. A motion absorbing system as in claim 13 , wherein said tube varies in diameter along the length thereof.

15. A motion absorbing system as in claim 13 , wherein a longitudinal axis of said tube is approximately perpendicular to said surface of said liquid.

16. A motion absorbing system as in claim 13 , wherein said elastic element is selected from the group consisting of a bellows disposed in said liquid and a balloon disposed in said liquid.

17. A motion absorbing system as in claim 13 , wherein said elastic element is coupled to said container.

18. A motion absorbing system as in claim 13 , wherein said container comprises a ballast tank.

19. A motion absorbing system as in claim 13 , further comprising a duct in fluid communication with at least two of said motion absorbers.

20. A method of absorbing motion experienced by a structure, said method comprising the steps of:
coupling at least one rigid container to a structure disposed in an environment capable of inducing movement of the structure, wherein each said rigid container has a liquid disposed therein and wherein a ullage is defined above a surface of said liquid; and
positioning an elastic element in said liquid disposed in each said rigid container, each said elastic element having a natural frequency tuned to damp motion of said liquid caused by the environment.

21. A method according to claim 20 , wherein said step of positioning includes the steps of:
providing a tube having a closed end and an open end; and
fixedly positioning said tube in said liquid wherein a piston of said liquid resides in said tube to seal said open end, and wherein a gas fills said tube between said piston and said closed end of said tube, said tube including a flow constrictor disposed therein such that said gas passes through said flow constrictor when said gas experiences compression and when said gas experiences expansion.

22. A method according to claim 21 , wherein said step of fixedly positioning said tube includes the step of aligning a longitudinal axis of said tube to be approximately perpendicular to said surface of said liquid.

23. A method according to claim 20 , wherein said step of positioning is selected from the group consisting of positioning a bellows in said liquid and positioning a balloon in said liquid.

24. A method according to claim 20 , wherein said step of positioning includes the step of coupling said elastic element to said container.

25. A method according to claim 20 , wherein the environment causes said movement of the structure in a plurality of dimensions, and wherein said at least one rigid container comprises a plurality of rigid containers having said liquid disposed in each of said rigid containers and having one said elastic element disposed in each said liquid, said method further comprising the step of arranging said plurality of rigid containers to damp said movement of the structure in the plurality of dimensions.

26. A method of absorbing motion experienced by a structure floating on a body of water, said method comprising the steps of:
providing a floating structure in a body of water, said floating structure including a ballast tank having ballast water disposed therein wherein a ullage is defined above a surface of said ballast water; and
positioning an elastic element in said ball

Assignees

• Univ Maine System

Inventors

• Allen Christopher K
• Viselli Anthony M
• Goupee Andrew J
• Dagher Habib J
• Berry Robert E
• Lindner Jeffrey L
• Gant Frederick S
• Townsend John S
• Williams Rebecca L

Classifications

• F16F15/022 Primary

  using dampers and springs in combination · CPC title

• F16F15/0232

  with at least one gas spring (F16F15/027 takes precedence) · CPC title

• F16F15/04

  using elastic means (single elements or their attachment F16F1/00 - F16F13/00); {(F16F15/023, F16F15/03 take precedence)} · CPC title

• F16F15/023

  using fluid means · CPC title

• F03D13/25 Primary

  specially adapted for offshore installation · CPC title