Some Effects of Amplitude and Frequency on the Aerodynamic Damping of a Model Oscillating Continuously in Yaw

Résumé du livre

A fuselage-vertical-tail combination was continuously oscillated in yaw through a range of reduced frequencies, which includes the range usually encountered in the lateral oscillations of airplanes, and through a range of amplitudes corresponding to the amplitudes of the sustained lateral oscillation (commonly called snaking) of certain airplanes. The damping in yaw was measured as a phase angle between the lateral force on the vertical tail and the displacement in yaw of the model for each amplitude and frequency condition. An indication of a reduction in damping in yaw appeared as the amplitude of oscillation was reduced through the range of small amplitudes investigated. The decrease of the lateral damping with reduced-frequency parameter at low frequencies of oscillation was slightly greater than the small variation predicted by the finite-span unsteady-lift theory but not so large as the variation indicated by two-dimensional theory.