Smooth sleeves for drag and VIV reduction of cylindrical structures
AssigneeShell Oil Company
InventorsDonald Wayne Allen, Dean Leroy Henning, David Wayne McMillan, Richard Bruce McDaniel, Kenneth Dupal
Life of this patent
Estimating the term…
Abstract
A method for controlling drag and vortex induced vibration in a substantially cylindrical element by providing an ultra-smooth surface about the cylindrical element. The system for controlling drag and vortex induced vibration utilizes a substantially cylindrical marine element having an ultra-smooth effective surface.
Claims22
A method of reducing drag and vortex induced vibration in a substantially cylindrical element comprising providing a substantially cylindrical marine element having an ultra-smooth surface about the cylindrical element having an average K/D ratio of less than 8.0×10−5 where:
- K is an average measure surface peak to trough distance and
- D is an effective outside diameter of the cylindrical element.
A method of reducing drag and vortex induced vibration about a substantially cylindrical marine element comprising providing an ultra-smooth surface coating about the cylindrical element having an average K/D ratio of less than 8.0×10−5 where:
- K is an average measured surface peak to trough peak distance;
- and
- D is an effective outside diameter of the cylindrical element including the coating.
A method of reducing drag and vortex induced vibration about a substantially cylindrical marine element comprising providing an ultra-smooth surface on a substantially cylindrical sleeve about the cylindrical element, the sleeve having an average K/D ratio of less than 8.0×10−5 where:
- K is an average measured surface peak to trough peak distance;
- and
- D is an effective outside diameter of the cylindrical element, including the sleeve.
A system for reducing drag and vortex induced vibration, comprising:
- a substantially cylindrical marine element having an ultra-smooth effective surface with an average K/D roughness parameter of less than 8.0×10−5, where:
- K is an average measured surface peak to trough peak distance;
- and
- D is an effective outside diameter of the cylindrical element.
A system for reducing drag and vortex induced vibration comprising:
- a substantially cylindrical marine element having an ultra-smooth coating material with an average K/D roughness parameter of less than 8.0×10−5 where:
- K is an average measured surface peak to trough peak distance;
- and
- D is an effective outside diameter of the cylindrical element including the coating.
A system for reducing drag and vortex induced vibration comprising:
- a substantially cylindrical marine element having an ultra-smooth substantially cylindrical sleeve surrounding the marine element with an average K/D roughness ratio of less than 8.0×10−5 where:
- K is an average measured surface peak to trough peak distance;
- and
- D is an effective outside diameter of the cylindrical element including the cylindrical sleeve.
Dependencies are inferred from the claim text.