초록 ▼

A hydrofoil device is useable as a hydrofoil wing, propeller blade, etc. In a water flow, a relatively lower pressure is generated on a second surface (94) of the device compared with a first surface (96). Near the trailing end of the first surface a protrusion in the form of an adjustable intercept

A hydrofoil device is useable as a hydrofoil wing, propeller blade, etc. In a water flow, a relatively lower pressure is generated on a second surface (94) of the device compared with a first surface (96). Near the trailing end of the first surface a protrusion in the form of an adjustable interceptor (98) is provided. The face of this protrusion defines an included angle to the upstream direction of less than or equal to 90.degree. so that water flow thereat is deflected back on itself thereby increasing the local pressure on the first surface. A second protrusion may be provided near the leading edge of the second surface (94) to encourage flow separation thereat. Air may be provided adjacent each protrusion to provide natural ventilation if the pressure of the water flow drops below atmospheric pressure.

대표청구항 ▼

1. An improved hydrofoil device, the hydrofoil device comprising:a first surface and a second surface located on an opposite side of the device to said first surface, wherein water flows over the first and second surfaces from a leading edge to a trailing edge of the device; and a protrusion provide

1. An improved hydrofoil device, the hydrofoil device comprising:a first surface and a second surface located on an opposite side of the device to said first surface, wherein water flows over the first and second surfaces from a leading edge to a trailing edge of the device; and a protrusion provided adjacent the trailing edge of the device so as to produce a surface discontinuity on said first surface, wherein said protrusion comprises a protrusion surface facing the upstream direction of the hydrofoil, and the protrusion surface defines an included angle to the upstream direction of the hydrofoil of less than or substantially equal to 90.degree., whereby, in use, water flowing over the first surface is deflected back on itself by the protrusion, and a resulting increase in the local pressure on said first surface upstream of said protrusion contributes substantially to the lift generated by the hydrofoil device.