Characterizing Aeroacoustic/Combustion Loads on Aging Aircraft

Period of Performance: 05/12/1999 - 06/12/2001


Phase 2 SBIR

Recipient Firm

Unistry Assoc., Inc.
1901 Darby Rd
Havertown, PA 19083
Principal Investigator

Research Topics


A program is proposed that predicts the aeroacoustic environment associated with flow-induced unsteady loads, including combustion and oscillating flow experienced from cavities and nozzle/screech. These loads are required in order to properly define the structural response to aging aircraft. The engineering prediction technique 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 sustainment while providing specifications for structural requirements for new platform designs. Sensitivity of the aeroacoustic environment has been demonstrated to have a significant impact on structural response and crack growth. 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/aeroacoustic community. The CD-ROM will include analysis, database, tables of design parameters to execute the analysis, example cases and user guide. A commercialization plan to market the CD-ROM will be developed. 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.