Generalized Formulation of Nonlinear Pitch-Yaw-Roll Coupling: Part I-Nonaxisymmetric Bodies

A nonlinear aerodynamic moment system, formulated in a previous study to apply to arbitrary motions of bodies of revolution in free flight, is generalized to include nonaxisymmetric bodies (e.g., aircraft) within a uniform treatment. Within the assumption of a linear dependence on coning rate, the total moment is shown to be compounded of the contributions from four simple motions and a clear physical meaning is attached to each contribution. Applied to aircraft motions, the formulation includes the nonlinear interactions between motions that normally are excluded in the classical treatment. The results may be useful in the design of experiments and the interpretation of results obtained therefrom.