Rotating Rake Design for Unique Measurement of Fan-Generated Spinning Acoustic Modes

By: Nasa, National Aeronautics and Space Adm

In light of the current emphasis on noise reduction in subsonic aircraft design, NASA has been actively studying the source of and propagation of noise generated by subsonic fan engines. NASA/LeRC has developed and tested a unique method of accurately measuring these spinning acoustic modes generated by an experimental fan. This mode measuring method is based on the use of a rotating microphone rake. Testing was conducted in the 9 x 15 Low-speed Wind Tunnel. The rotating rake was tested with the Advanced Ducted Propeller (ADP) model. This memorandum discusses the design and performance of the motor/drive system for the fan-synchronized rotating acoustic rake. This novel motor/drive design approach is now being adapted for additional acoustic mode studies in new test rigs as baseline data for the future design of active noise control for subsonic fan engines. Included in this memorandum are the research requirements, motor/drive specifications, test performance results, and a description of the controls and software involved. Konno, Kevin E. and Hausmann, Clifford R. Glenn Research Center RTOP 535-03-01...

• Format: Paperback
• Language: English
• ISBN: 1728958598
• ISBN13: 9781728958590
• Release Date: January 1
• Publisher: Independently Published
• Length: 26 Pages
• Weight: 0.19 lbs.
• Dimensions: 0.1" x 8.5" x 11.0"