SBIR-STTR Award

Characterizing Aeroacoustic/Combustion Loads on Aging Aircraft
Award last edited on: 6/14/2002

Sponsored Program
SBIR
Awarding Agency
DOD : AF
Total Award Amount
$737,166
Award Phase
2
Solicitation Topic Code
AF98-176
Principal Investigator
Ronald L Hinrichsen

Company Information

Unistry Associates

101 West Eagle Road Suite 201
Havertown, PA 19083
   (610) 853-1313
   cpacpas@aol.com
   N/A
Location: Single
Congr. District: 05
County: Delaware

Phase I

Contract Number: F33615-98-C-3203
Start Date: 4/30/1998    Completed: 2/28/1999
Phase I year
1998
Phase I Amount
$99,932
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.

Keywords:
Cavity Noise Fatigue Acoustic Loads Screech Aging Aircraft Unsteady Flow Combustion Noise Noise

Phase II

Contract Number: F33615-99-C-3204
Start Date: 5/12/1999    Completed: 6/12/2001
Phase II year
1999
Phase II Amount
$637,234
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.

Keywords:
Acoustic Loads Aging Aircraft Cavity Noise Combustion Noise Fatigue Noise Screech Unsteady Flow