Characterizing Aeroacoustic/Combustion Loads on Aging Aircraft

A program is proposed that will estimate aerodynamic flow induced and unsteady pressure oscillations in flight that will provide the dynamic loads for structural vibration response to aging aircraft. The engineering prediction technique, which is based on first principals, provides for a close-form solution and has been validated for subsonic, transonic, and supersonic flows subject to attached and separated flow conditions. The methodology correctly describes the acoustic power intensity and spectra required for fatigue analysis and structural response for aging aircraft repair/maintenance while providing specifications for structural requirements for new platform designs.The focus of the research is to develop a database of attached and separated flows generated by control surface interactions, cavities, engine inlet/combustion/nozzle, and exhaust plume (screech). The database will be formatted into a CD-ROM for application to the aging aircraft community. The CD-ROM will include analysis, database, tables of design parameters to execute the analysis, example cases and user guide. Support of this program will be provided by Boeing-St Louis. It is further proposed to reach a large segment of the aging aircraft community through the Internet to allow collection of data, dissemination of data, and to provide a vehicle for feedback on aging aircraft problems.