Blade tonal noise reduction using tail articulation at high Reynolds number

The biologically inspired method of tail articulation is investigated as a means of reducing tonal noise due to the stator wake blade interaction in underwater vehicles. This work is experimental in nature and conducted in the closed channel water tunnel at Naval Undersea Warfare Center in Newport, Rhode Island. Tail articulation is carried out with a life scale stator model with hinged flapping tail designed to (i) operate in freestream velocities corresponding to Reynolds number in the range 75,000 < Re < 300,000 and (ii) operate at frequencies up to 30 Hz in order to investigate the range of Strouhal number 0.0 < St < 0.35. Velocity measurements in the active stator wake are carried out by Laser Doppler Velocimetry, LDV, and Particle Image Velocimetry, PIV, in order to investigate the effects of tail articulation. Time averaged measurements of the stator wake by LDV show that Strouhal number of the tail articulation has a dominant effect on the time mean stator drag. Instantaneous phase averaged measurements of the stator wake by PIV show three regimes of the stator wake as Strouhal number is increased; quasi-steady wake spreading, vortex roll up, and strong vortex wake. A low order model describing the creation and convection of vorticity by tail articulation is developed which describes wake phenomena observed in experimental measurements. A two dimensional blade force simulation coupled with the reduced order tail articulation model is used to perimetrically search for a tail motion resulting in lower unsteady blade forces.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2005

Author dc:creator

• Macumber, Daniel Lee, 1981-

Advisor dc:contributor.advisor

• Anuradha M. 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

en_US

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/27879

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/27879