| CPC B63H 1/18 (2013.01) [B63H 1/20 (2013.01); B63H 1/26 (2013.01)] | 19 Claims |
|
1. A vehicle having a general direction of movement relative to a liquid that has a surface, said surface being essentially a free surface shared with a gas, said gas being at an ambient pressure, and said general direction of movement being substantially parallel to said surface, comprising:
a. said vehicle having a reference base plane established as a mean waterline plane when said vehicle is floating at rest at said surface of said liquid, and a centerline reference plane extending along a central longitudinal axis and being perpendicular to said reference base plane,
b. said vehicle having at least one pair of blades, said pair of blades comprising two individual blades opposing one another about said reference centerline plane, each of said blades having a base, a tip, a leading edge, a trailing edge, a low pressure surface and a high pressure surface, each one of said leading edges and respective said trailing edges converging toward respective said tips, said leading edges being substantially closer to said trailing edges at said tips than at said bases, and each one of said low pressure surfaces and respective said high pressure surfaces converging at respective said leading edges and at respective said trailing edges, and said pair of blades being attached to said vehicle and extending from said vehicle in such a way that said tips can be substantially below said waterline plane,
c. said pair of blades having attachments to said vehicle at predetermined points such that in operation at least one of said blades extend substantially downward toward said tips and penetrate said liquid's surface, said blades having an angle of attack in said liquid defined respectively by an angle between said general direction of movement of said vehicle in said liquid and a chord of said blades, and said blades being configured such that in operation an exposed portion of said blades is above said liquid's surface, and a submerged portion of said blades is below said liquid's surface, and such that said leading edges part said liquid at said submerged portion, said blades being further configured such that in operation at a predetermined speed, said angle of attack provides a high pressure in said liquid on said submerged portion of said high pressure surfaces of said blades and a low pressure in said liquid on said low pressure surfaces of said blades that is below said liquid's surface, said high pressure providing thrust in a combination of a lateral direction and an upward direction, said low pressure being substantially low enough to draw down said gas from said liquid's surface, said gas being essentially drawn down contiguous to said low pressure surface, and said gas creating voids in said liquid contiguous to said low pressure surfaces, said voids being filled with said gas at substantially said ambient pressure, and in operation said voids being able to extend behind said blades in said liquid, and each of said submerged portions of said high pressure surfaces of said blades being essentially a wetted high pressure surface, and each of said low pressure surfaces being essentially an ambient pressure dry surface, whereby said blades are in a vented state, and whereby said vented state prevents cavitation of said blades, and
d. said angle of attack being further configured such that in operation, at said predetermined speed, said upward thrust be sufficient to support part or all of said vehicle at a predetermined height above said liquid's surface.
|