Reduction of unsteady underwater propeller forces via active tail articulation

This study investigates the use of biologically-inspired tail articulation as a means to reduce unsteady propeller forces and by extension, noise due to stator wake blade interaction. This study is experimental in nature and testing was completed in a closed-channel water tunnel at the Naval Undersea Warfare Center in Newport, RI. A propeller-force measurement apparatus was designed and built to measure the forces and moments created by a spinning propeller behind a life scale stator model. Tests were conducted at a Reynolds number of 75,000 and stator tail articulation was carried out in the range of Strouhal number 0.0 < St < 0.13. A variety of non-lifting propellers were used to investigate sinusoidal articulation profiles in the range of am- plitudes (2°,5°,10°), and phase angles between propeller blades and stator (0°- 360°). It was found that stator articulation is capable of reducing the RMS of both unsteady thrust force and its time derivative as compared with a baseline static stator wake by choosing a suitable Strouhal number and phase angle. Tail articulation at St < 0.08 showed reduced unsteady forces for certain phase angles, while other phase angles demonstrated unsteady forces greater than the baseline wake.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2006

Author dc:creator

• James, Richard A. (Richard Alexander), 1982-

Advisor dc:contributor.advisor

• Anuradha Annaswamy.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/36240

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/36240