Advanced Subsonic Technology (AST) Separate-Flow High-Bypass Ratio Nozzle Noise Reduction Program Test Report

摘要: NASA s model-scale nozzle noise tests show that it is possible to achieve a 3 EPNdB jet reduction with inwardfacing chevrons and flipper-tabs installed on the primary fan chevrons. These tabs are simple devices easy be incorporated into existing short duct separate-flow nonmixed exhaust systems. However, these expected cause some small amount of thrust loss relative axisymmetric baseline system. Thus, important have further tested in calibrated performance test facility quantify performances devices. The choice or for suppression would most likely based results conducted by Aero System Engineering (ASE) Inc. It anticipated promising concepts identified from this program will validated full scale engine at both Pratt & Whitney Allied-Signal, under funding Engine Validation Noise Reduction Concepts (EVNRC) programs. This bring technology readiness level point where could high confidence either new turbofan engines having short-duct, nacelles.