Lifting body water jet propulsion inlet inductor

Abstract

A foil shaped lifting body is attached by means of a strut to the underwater body of a vessel in such a manner as to cause a standing wave to be developed when the vessel is in operation in order that the standing wave will induct water into machinery intakes. The technology of this invention is particularly applicable to the operation of waterjet marine propulsion systems.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing objects and other features and advantages of the present invention will be more fully understood by reference to the following detailed description when read in conjunction with the accompanying drawings wherein like reference numerals refer to like or corresponding elements throughout and wherein:

FIG. 1 is a partial perspective bottom view of a watercraft vessel constructed in accordance with the present invention showing a lifting body mounted to the vessel in proximity to its waterjet inlet;

FIG. 2 is a side view of the vessel shown in FIG. 1 showing the leading edge of the lifting body 5 approximately ⅔ of the length of the intake opening 2 from the forward edge of the opening;

FIG. 3 is a schematic sectional view of the vessel shown in FIG. 1 taken along line 1-1 of FIG. 2, showing the placement of the lifting body 5 relative to the water intake;

FIG. 4 is a schematic sectional view of the vessel shown in FIG. 1 taken along line 2-2 of FIG. 2, showing the placement of the lifting body 5 and the strut 6 connecting it to the hull 1;

FIG. 5 is a pressure diagram showing water pressure on the lifting body and the standing wave and free water surface above it; and

FIG. 6 is a side schematic view of a watercraft vessel and the standing wave created by the lifting body.

Claims

1. A watercraft hull including a hull bottom located below the design waterline of the hull; waterjet propulsion means in the hull; a water intake port in said hull bottom for supplying water to said waterjet propulsion means; said intake port having fore and aft edges; and a lifting body mounted on said hull below said hull bottom adjacent to said water intake port in a position to create a standing water wave at the intake port for supply of water to the waterjet propulsion means.

2. A watercraft hull as defined in claim 1 wherein said lifting body is foil shaped in vertical longitudinal cross-section.

3. A watercraft hull as defined in claim 1 wherein said lifting body has a leading edge located beneath said water intake port of the hull.

4. A watercraft hull as defined in claim 3 wherein said leading edge of the lifting body is located aft of the fore edge of the intake port a distance approximately two thirds of the distance between the fore and aft edges of said intake port.

5. A watercraft hull as defined in any one of claims 1, 2, 3 and 4 wherein the lifting body is secured to said hull by a single generally vertically extending strut.

6. A watercraft hull as defined in claim 5 wherein said strut is foil shaped in horizontal longitudinal cross-section.

7. A watercraft hull as defined in claim 6 wherein said lifting body is spaced by said strut from the hull bottom at a distance sufficient for the lifting body to form a standing wave on the surface of the water in which the hull is supported whereby the pressure of the water beneath the hull at the standing wave is increased and water is forced into said intake port.