Abstract:

A nonlinear aerodynamic model for a symmetric vehicle has been identified by applying the maximum likelihood technique to flight testing data. In accordance with the characters of the flight, a three degree of freedom method of the longitudinal motion equations coupled with lateral motion parameters is adopted. A new mathematical model of nonlinear aerodynamics including the influence of Mach number is presented. The results show that the method is particularly applicable to estimating nonlinear aerodynamic coefficients at high angles of attack.

Key words: aerodynam ic coefficients, ident ificat ion, modelling