US 6,805,067 B1 · Contour stern flap

Abstract

A stern flap has a “contour” shape which facilitates installation thereof upon the curved stern of a ship. The stem flap's lower surface includes an intermediate region and two curvedly tapered end regions. The intermediate region is delineated forwardly by a curved leading edge and aftly by a parallelly curved trailing edge, the chord length therebetween being constant. The curve characterizing the flap's leading edge is congruent with the curve characterizing the ship stern's lower transverse edge (the junction between the ship's bottom and the ship's stern), thereby permitting contiguous disposition of the flap's leading edge relative to the ship's lower transverse edge, as well as permitting even and unbroken disposition of the flap's lower surface relative to the ship's bottom. The contour stem flap “fits” the ship's stern, thus lending itself to a hydrodynamically propitious mode of attachment whereby hydrodynamic efficiency is uncompromised.

Claims16

Dependent claims

For use in association with a nautical vehicle including a stern and bottom, said stern and bottom forming a crosswise junction, said crosswise junction being characterized by a stern curvature across said stern, an adjunctive device including a leading edge and a trailing edge, said leading edge being characterized by a leading edge curvature which at least substantially conforms with at least a portion of said stern curvature, said trailing edge curvature being characterized by a trailing edge curvature which is parallel to said leading edge curvature, said adjunctive device being adaptable to association with said nautical vehicle so that said leading edge and at least a portion of said crosswise junction are nearly coincident, said trailing edge curvature thereby being approximately parallel to said at least a portion of said stern curvature.

A method of changing the hydrodynamic character of a hullform having a stern surface and a hull-bottom surface conjoinedly defining a curvilinear transverse stern edge, said method comprising:

providing a flap having a curvilinear leading flap edge, a curvilinear trailing flap edge and a flap undersurface delimited by said leading flap edge and said trailing flap edge, wherein the curvilinearity of said leading flap edge is at least substantially equivalent to the curvilinearity of at least a portion of said transverse stern edge, and wherein the curvilinearity of said trailing flap edge is parallel to the curvilinearity of said leading flap edge;
and
coupling said flap with said hullform so that said leading flap edge and said at least a portion of said transverse stern edge are at least substantially adjacent, thereby generally establishing a continuity between said hull-bottom surface and said flap undersurface wherein the curvilinearity of said trailing flap edge is at least substantially parallel to the curvilinearity of said at least a portion of said transverse stern edge.

The combination comprising a marine hull and a stern flap, wherein:

said hull includes an underside, a transom and a knuckle edge;
said underside and said transom meet at said knuckle edge;
said knuckle edge is arcuate athwart said hull;
said stern flap includes a lower surface, a port tip, a starboard tip, a leading edge and a trailing edge;
said lower surface is characterized by a span length;
said lower surface includes a port surface section, a starboard surface section and a chord surface section;
said chord surface section is intermediate said port surface section and said starboard surface section;
said chord surface section is characterized by a chord length;
said chord surface section is bounded by said leading edge and said trailing edge;
said leading edge and said trailing edge are each arcuate along said span length;
said chord length is the perpendicular distance measured between said leading edge and said trailing edge and along said chord surface section;
said span length is the distance measured between said port tip and said starboard tip and along said lower surface;
said leading edge fits said knuckle edge so that said leading edge at least substantially abuts said knuckle edge;
and
said trailing edge and said leading edge are parallel with respect to each other so that throughout said chord surface section said chord length is constant.

12 more elements

Dependencies are inferred from the claim text.

Contour stern flap

Life of this patent

Contour stern flap

Life of this patent

Abstract

Claims16