Predictor of Aircraft Structural Loads Due to Buffet

Buffet is a significant loading source on an aircraft that must be properly accounted for in order to obtain accurate design loads during the initial design phase as well as accurate fatigue loads to properly track the service life of the aircraft. When flow separation occurs during maneuvering outside of the linear aerodynamic regime, the resulting turbulent flow induces oscillations on the local structure as well as on aircraft components downstream of the turbulent wake. A classic example of this occurs when flow separates from a wing during high angle-of-attack maneuvers. Not only does the load on the wing become oscillatory, but also the horizontal stabilizer responds to the turbulent flow and experiences oscillatory loading on top of the steady load from the maneuver. This SBIR will address the deficiencies that currently exist is buffet prediction methodologies by coupling analytical turbulent flow methodologies and non-linear structural models with recorded test data. The resulting system will be an end user software package that will allow streamlined changes to the outer mold line (OML) to see the effects on airframe life and design loads.