Nonlinear sloshing and the coupled dynamics of liquid propellants and spacecraft

Abstract : Current and future space-based systems have rather complex mission requirements which demand the storage of large amounts of liquid propellants on board. With large controller bandwidths and rapid maneuvering of the spacecraft in a low gravity environment, potential coupling between the sloshing liquid, the spacecraft motion and structural modes need to be carefully evaluated to ensure the system design adequacy. For achieving the mission success, the first important step is to understand the nonlinear dynamics of the liquid sloshing. The report summarizes a two-year study on the development and application of the numerical method for three-dimensional liquid sloshing simulation. Fluid dynamics and fluid loading, including total force and impact for the vessel undergoing rapid movement were simulated. Effects of baffles and active baffles with or without feedback mechanism for sloshing control were compared. It was found that moving baffles can be very effective in suppressing large amplitude sloshing. Complicated swirling intensification by drainage was also numerically simulated. Sloshing, Breaking wave, VOF method, active control