87-33: PROPELLER WAKE INDUCED STRUCTURE-BORNE INTERIOR NOISE

THIS PROPOSAL OUTLINES A STUDY TO ESTABLISH A UNIFIED PREDICTION MODEL FOR THE CONTRIBUTION TO AIRCRAFT INTERIOR CABIN NOISE RESULTING FROM WING MOUNTED PROPELLER, WAKE INDUCED, STRUCTURE-BORNE NOISE TRANSMITTED THROUGH THE WING. THE METHOD USES: (1) A VELOCITY DEFECT MODEL REPRESENTING THE VISCOUS WAKE BEHIND A TWISTED AND LEANED PROPFAN BLADE; (2) STANDARD ACOUSTIC SOURCE MODELING METHODS TO DESCRIBE THE WING VIBRATION AND PRESSURE LOADING PERTURBATION RESULTING FROM THE WAKE SLAPPING THE WING; AND (3) FINITE ELEMENT, ACCOUSTIC STRUCTURE INTERACTION ANALYSIS TO PREDICT THE VIBRANCY ENERGY TRANSMISSION THROUGHTHE WING STRUCTURE, EXCITATION OF THE REST OF THE AIRCRAFT STRUCTURE, AND THE RESULTING NOISE RADIATION TO THE INTERIOROF THE AIRCRAFT CABIN.