An experimental study of the effect of length of acoustic treatment was performed on a full scale fan using two different inlets. Analysis of the data revealed that measured suppression varied linearly with the length of the ringed linear segments as anticipated. Further analysis indicated that the wall only portion of the treatment was substantially more effective than anticipated suggesting that, if only moderate suppression is needed, wall only treatment may suffice. Contrary to expectation the two inlets behaved similarly. Introduction of a hard exhaust splitter into the configuration resulted in a noise increase at certain frequencies.
An experimental study of the effect of treated length on fan inlet noise suppressors
American Institute of Aeronautics and Astronautics, Aerospace Sciences Meeting ; 1975 ; Pasadena, CA
1975-01-01
Conference paper
No indication
English
Performance of inlet sound suppressors
NTRS | 1968
|Performance of Inlet Sound Suppressors
NTIS | 1968
|