Reduction of fan noise emanating from turbofan engines by using acoustically treated nacelles is considered. Test performance prediction for an acoustically lined nacelle having a three ring inlet, a single ring fan duct, and external cowling expect a 15 PNdb fan noise reduction with 5 percent takeoff thrust loss and a 5.4 percent cruise specific fuel consumption increase.
Quiet engine nacelle design
1972-01-01
Miscellaneous
No indication
English