Bluff body energy converter

• US 20060064972A1
• Filed: 01/13/2005
• Published: 03/30/2006
• Est. Priority Date: 01/14/2004
• Status: Active Grant

• Current Assignee: Ocean Power Technologies, Inc.
• Original Assignee: Ocean Power Technologies, Inc.
• Inventors: Allen, James J.
• Granted Patent: US 7,224,077 B2
• Time in Patent Office: Days
• US Class Current: 60/369
• CPC Class Codes: F03D 5/00 Other wind motors controlling thereof F03D7/00
• CPC Class Codes: F03D 5/06 the wind-engaging parts swinging to-and-fro and not rotating
• CPC Class Codes: F05B 2210/16 Air or water being indistinctly used as working fluid, i.e. the machine can work equally with air or water without any modification
• CPC Class Codes: F05B 2260/96 Preventing, counteracting or reducing vibration or noise
• CPC Class Codes: Y02E 10/70 Wind energy

Abstract

A power generating system comprising a bluff (non-streamlined) body placed in a fluid stream at ninety degrees to the flow direction creates a von Karman vortex street behind the body. In the process, feedback forces are generated that excite the bluff body into oscillation. The bluff body oscillatory movements are coupled to and energize a power generator. Means are employed for electrically varying the natural frequency characteristics of the bluff body such that, over a relatively wide range of fluid flow velocities, the bluff body oscillates at a resonant frequency of the body for maximum energy transfer from the fluid stream to the bluff body.

Claims

1. A method of generating power that utilizes the shedding of vortices from a bluff body comprises placing a bluff body within and perpendicular to a flowing fluid stream for driving the bluff body into oscillations, and coupling the bluff body to an energy converter for converting the oscillatory motions of the bluff body into useful energy.

2. A method according to claim 1 including electrically adjusting the oscillatory characteristics of the bluff body in accordance with the flow characteristics of the fluid stream so that the bluff body vibrates in resonance in response to a range of flowing streams.