Claims
- 1. A method for reducing cavitations of a marine propeller, comprising the steps of:locating a mechanical wave generating transducer at the leading edge of said propeller; and, driving said transducer with a periodic signal to produce energy in the 1 KHz to 10 MHz range, whereby pressure at said leading edge of said propeller is increased to reduce cavitations.
- 2. The method of claim 1, and further including locating a second transducer at the trailing edge of said propeller.
- 3. A method for improving the flow characteristics of a marine propeller, comprising the steps of:locating a mechanical wave generating transducer at said propeller; and, driving said transducer with a periodic signal to produce energy in the 1 KHz to 10 MHz range, whereby pressure across said propeller is controlled to improve flow.
- 4. The method of claim 3, wherein said transducer includes a phased array and wherein the phasing of said phased array is used to control flow over said propeller.
- 5. The method of claim 3, wherein said propeller has a leading edge and wherein said transducer is at said leading edge.
- 6. The method of claim 3, wherein said propeller has a trailing edge and wherein said transducer is at said trailing edge.
- 7. The method of claim 6, wherein the opening angle at the trailing edge is changed based on the output of said transducer.
- 8. The method of claim 3, wherein the flow characteristic controlled by said transducer alters the properties of said propeller.
- 9. The method of claim 8, wherein one of said properties is lift.
- 10. The method of claim 8, wherein one of said properties is pitch.
- 11. The method of claim 8, wherein one of the properties is thrust.
- 12. The method of claim 8, wherein one of said properties is drag.
- 13. The method of claim 3, wherein said propeller is shrouded and wherein said transducer is in said shroud.
- 14. A method for improving the flow characteristics of a marine foil, comprising the steps of:locating a mechanical wave generating transducer at said foil; and, driving said transducer with a periodic signal to produce energy in the 1 KHz to 10 MHz range, whereby pressures across said foil are controlled to improve flow.
Parent Case Info
This application is a divisional of U.S. patent application Ser. No. 09/294,220, filed Apr. 16, 1999, pending.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
4170185 |
Murphy et al. |
Oct 1979 |
|
5735226 |
McNeal |
Apr 1998 |
|