Determination of transonic unsteady aerodynamic loads to predict the aeroelastic stability of fighter aircraft

A model for determining aerodynamic loads from steady and unsteady data bases is presented that is suitable for predicting Limit Cycle Oscillations (LCO) of fighter aircraft at transonic speeds. Validations of the model will be presented, in particular the influence of Mach number variations, different control flap settings and oscillation frequency and amplitude are demonstrated. A few examples of the aerodynamic model embedded in the LCO prediction method are presented to show the LCO characteristics of a fighter type aircraft. Finally, enhancement of the use of the model will be discussed by extension of the data bases with data obtained from CFD methods and/or new wind tunnel experiments.