Pitch damping identification in high speed regimes with a free-to-tumble rig

Abstract

Many re-entry bodies, even if they are debris or not, have nonlinear dynamic stability characteristics that produce oscillations in flight. The free-to-tumble techniques can be used to extract damping coefficient of specific body for planetary entry. The curve fitting approach is used to predict oscillatory behavior and the damping coefficient for the various test conditions of the wind tunnel obtained after the experimental data. The analysis presented provides an overview of the free-to-tumble test techniques and illustrates the effects of dynamic stability of the inter-stage tronconical system. It is proposed that these test techniques and curve fitting solution be refined in the future to better define the dynamic stability curves for the re-entry bodies.