Acoustic source and data acquisition system for a helicopter rotor blade-vortex interaction (BVI) noise reduction experiment
By:  Brian D. Roth
Publisher: Naval Postgraduate School; Available from National Technical Information Service
Published: 1996
Place of publication: Monterey, Calif; Springfield, Va
Language: eng
Number of pages: 62
Description: One of the most objectional noises produced by a helicopter is due to interaction of a rotor blade with a previously shed vortex. Various methods have been proposed to reduce this blade/vortex interaction (BVI) noise; this investigation is concerned with BVI noise reduction      by rotor blade tip design modifications. Potentially much can be learned regarding the prospect for success of a candidate rotor blade design at greatly reduced time and money by      performing acoustic scattering measurements in an anechoic chamber. It is proposed that a rotor blade which scatters acoustic waves less could be expected to produce less BVI noise.   This thesis describes the development of the acoustic source and computer controlled data acquisition system for such a scattering experiment.
Notes: "December 1996."

Thesis advisor(s): Robert M. Keolian,  Steven R. Baker.

Thesis (M.S. in Engineering Acoustics) Naval Postgraduate School, December 1996.

Includes bibliographical references (p. 59).

Approved for public release; distribution unlimited.

Also available online.

Mode of access: World Wide Web.

System requirements: Adobe Acrobat Reader.

US Navy (USN) author.

dk/dk cc:9116 07/25/97.