Apparatus and method for reducing fluid drag on a submerged surface
AssigneeNorth Shore Partners
InventorsDonald P. Stubblefield, Jerry D. Stubblefield
Life of this patent
Estimating the term…
Abstract
An apparatus and method for reducing surface friction drag on the hull of a surface vessel by entraining air into water flowing in the boundary layer flow along the hull. The apparatus creates a reduced pressure region by diverting a first portion of the flow away from the surface of the hull. An air pocket is formed in the reduced pressure region and a second portion of the flow is directed through the air pocket by nozzles, which acts as a plunging jet and entrains air into the boundary layer.
Claims18
An apparatus that entrains a secondary fluid into a primary fluid flow while the primary fluid flows along a surface of an object, the apparatus comprising:
- an inlet through which a first portion of the primary fluid flows, the first portion of the primary fluid entering the inlet through a first opening and exiting the inlet through at least one nozzle;
- a flow diverting member, at least a portion of the flow diverting member being located downstream from the first opening of the inlet, a second portion of the primary fluid flowing over the flow diverting member;
- a second opening that enables the secondary fluid to flow into a first region, the second opening being located at or downstream from the flow diverting member and the first region being between the surface of the object and the second portion of the primary fluid;
- a free surface consisting of an area in which the second portion of the primary fluid abuts the first region;
- and
- wherein the at least one nozzle directs the first portion of the primary fluid through the free surface.
A method for reducing frictional drag on a hull of an object designed to be propelled through a primary fluid, the hull having a surface that is at least partially submerged in the primary fluid, the method comprising:
- separating a first portion of the primary fluid from a second portion of the primary fluid, which results in a reduced pressure region located between the second portion of the primary fluid and the surface of the object;
- providing an opening that enables a secondary fluid to flow into the reduced pressure region, the secondary fluid having a lower density than the primary fluid;
- and
- entraining at least a portion of the secondary fluid into a portion of the primary fluid by impinging the second portion of the primary fluid with the first portion of the primary fluid.
Dependencies are inferred from the claim text.