Rotating Rake Turbofan Duct Mode Measurement System

By: Administration (Nasa), National Aeronaut

An experimental measurement system was developed and implemented by the NASA Glenn Research Center in the 1990s to measure turbofan duct acoustic modes. The system is a continuously rotating radial microphone rake that is inserted into the duct. This Rotating Rake provides a complete map of the acoustic duct modes present in a ducted fan and has been used on a variety of test articles: from a low-speed, concept test rig, to a full-scale production turbofan engine. The Rotating Rake has been critical in developing and evaluating a number of noise reduction concepts as well as providing experimental databases for verification of several aero-acoustic codes. More detailed derivation of the unique Rotating Rake equations are presented in the appendix. Sutliff, Daniel L. Glenn Research Center NASA/TM-2005-213828, E-15187 WBS 22-781-30-74 AEROACOUSTICS; ACOUSTIC PROPERTIES; ACOUSTIC DUCTS; AERODYNAMIC NOISE; TURBOFANS; NOISE REDUCTION; LOW SPEED; DUCTED FANS; TURBOFAN ENGINES; ROTATION

• Format: Paperback
• Language: English
• ISBN: B08FB24YRR
• ISBN13: 9798672725338
• Release Date: January 1
• Publisher: Independently Published
• Length: 34 Pages
• Weight: 0.23 lbs.
• Dimensions: 0.1" x 8.5" x 11.0"