NASA Advanced Propeller Research

By National Aeronautics and Space Administration

Acoustic and aerodynamic research at NASA Lewis Research Center on advanced propellers is reviewed including analytical and experimental results on both single and counterrotation. Computational tools used to calculate the detailed flow and acoustic fields are described along with wind tunnel tests to obtain data for code verification. Results from two kinds of experiments are reviewed: (1) performance and near field noise at cruise conditions as measured in the NASA Lewis 8- by 6-foot Wind Tunnel; and (2) far field noise and performance for takeoff/approach conditions as measured in the NASA Lewis 9- by 15-foot Anechoic Wind Tunnel. Detailed measurements of steady blade surface pressures are described along with vortex flow phenomena at off-design conditions. Near field noise at cruise is shown to level out or decrease as tip relative Mach number is increased beyond 1.15. Counterrotation interaction noise is shown to be a dominant source at takeoff but a secondary source at cruise. Effects of unequal rotor diameters and rotor-to-rotor spacing on interaction noise are also illustrated. Comparisons of wind tunnel acoustic measurements to flight results are made. Finally, some future directions in advanced propeller research such as swirl recovery vanes, higher sweep, forward sweep, and ducted propellers are discussed. Groeneweg, John F. and Bober, Lawrence J. Glenn Research Center RTOP 535-03-01...

• Format: Paperback
• Language: English
• ISBN: 1729025897
• ISBN13: 9781729025895
• Release Date: January 1
• Publisher: Independently Published
• Length: 38 Pages
• Weight: 0.25 lbs.
• Dimensions: 0.1" x 8.5" x 11.0"