Field test of muffler designed with aid of this method was conducted on helicopter with known exhaust-noise problem. When exhaust noises were compared for hover-flight conditions, muffler system was found to reduce exhaust noise by approximately 11 db. No significant degradation in engine performance was observed.
Improved method for design of expansion-chamber mufflers with application to operational helicopter
1974-03-01
Miscellaneous
No indication
English