A scale model Advanced Ducted Propulsor (ADP) was tested in NASA Lewis Research Center's 8- by 6-Foot Wind Tunnel to obtain acoustic data at cruise conditions. The model, designed and manufactured by Pratt & Whitney Division of United Technologies, was tested with three inlet lengths. The model has 16 rotor blades and 22 stator vanes, which results in a cut-on condition with respect to rotor-stator interaction noise. Comparisons of the noise directivity of the ADP with that of a previously tested high-speed, unducted propeller showed that the ADP peak blade passing tone was about 30 dB below that of the propeller, and therefore, should not present a cabin or enroute noise problem. The maximum blade passing tone first increased with increasing helical tip Mach number, peaked, and then decreased at a higher Mach number. The ADP tests with the shortest inlet showed more noise in the inlet arc than did tests with either of the other two inlet lengths.
Cruise Noise Measurements of a Scale Model Advanced Ducted Propulsor
1993
12 pages
Report
Keine Angabe
Englisch
Aircraft , Jet & Gas Turbine Engines , Noise Pollution & Control , Acoustics , Ducted fans , Inlet airframe configurations , Noise intensity , Noise measurement , Propeller blades , Propeller noise , Scale models , Propellers , Sound pressure , Acoustic properties , Cruising flight , Ducted fan engines , Engine noise , Mach number , Stator blades , Vanes , Wind tunnel tests
Cruise Noise Measurements of a Scale Model Advanced Ducted Propulsor
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