Novel 6dof EMM for Propellant Sloshing in Zero-Gravity (Wobbling Mass Model)

The present work is to introduce a novel mechanical model where the mass of fuel wobbles in the partially filled tank without a constrains surface as it is the case for the CSM (Constrained Surface Model) neither a pendulum fixed length as in the pendulum model nor restrictions to small amplitude linear dynamics as it is the case in spring mass models. The mass of fuel, as it is the real case in microgravity environment does not maintain contact for the whole time with the wall tank, however, in response to the strong motions of the tank-wall during maneuvers, the propellant mass thanks to its surface tension wobbles after the assumed elastic collision in different directions accordingly to the excitation forces direction. In addition to the description of the mechanical model, in order to determine the parameters of the novel 6dof EMM, an analogy between the propellant and the model has been established. Hooke’s law and Hertz theory are used for the analogy. Results of numerical simulations of the introduced model are represented applied in microgravity on a flexible satellite with a partially filled spherical tank. An example of a 6dof uniform wave-based control has been applied on the dynamic model of an orbiting satellite.