COMPARISON OF FILLED AND PARTLY FILLED NUTATION DAMPERS. - Texas A&M University (TAMU) Scholar

Fully filled viscous ring dampers cannot adversely affect spacecraft mass properties, but motion of fluid in such dampers is only weakly coupled with spacecraft motion, whereas partly filled rings alter mass properties, but can be strongly coupled with nutation. Even in the less effective 'spin synchronous' mode partly filled dampers usually damp nutation dramatically faster than fully filled dampers. In addition, the small nutation angle performance of a partly filled ring can be substantially improved by offsetting the axis of the ring from the spin axis to produce resonant coupling. In this paper nutation decay expressions for these dampers are obtained and compared for a symmetric dual-spin spacecraft. Identifical expressions were obtained from an energy sink analysis. The exact equations of motion were integrated numerically and compared to the approximate analytic solutions to show that the analytical expressions are accurate.

COMPARISON OF FILLED AND PARTLY FILLED NUTATION DAMPERS. Academic Article