Characterization of unconventional multi-dimension wing rock phenomenon

In order to investigate thoroughly the influence of the pitching disturbance on the lateral-directional wing rock, this paper modified Ananthkrishnan's large-amplitude model by simplifying the longitudinal perturbation model and adding such angle of attack(AOA) perturbation into evaluations of all the lateral-directional aerodynamic coefficients, instead of merely working over the coupling effect. Subsequently, a quantitative analysis concerning the unconventional complex wing rock phenomenon including the roll jump, the chaos and the multi-period oscillation, was conducted by fluctuating the longitudinal frequency factor and the lateral-longitudinal coupling index at existence of the internal resonance. The result of the parametric fluctuation analysis demonstrates that the infinitesimal longitudinal oscillation could not be safely neglected since it potentially holds a profound impact on the dominant lateral-directional movement, especially in condition of internal resonance.