AN EQUIVALENT MECHANICAL MODEL FOR LIQUID SLOSHING ON SPACECRAFT

Abstract

In order to improve the accuracy of the attitude control problem encountered by spacecraft with liquid containers, a study on dynamic modeling of liquids in moving containers is conducted. As a result, a new equivalent mechanical model which can describe the relative rolling movement of the liquid to the containers is proposed, using the method of Finite-element along with Fluid mechanics. The new equivalent mechanical model has one more degree of freedom and better identification of the viscous resistance compared with the old ones. Therefore, the dynamic influences on the spacecraft caused by the sloshing of the liquid during the attitude maneuvering procedure can be calculated more accurately by using the new model and so is the changing of dynamic factors, as well as the dynamic influence caused by the viscous resistance between the liquid and the container. The research results can provide theoretical basis for attitude control problem of spacecraft with liquid containers and thus achieve the purpose of improving control accuracy. The simulation results demonstrate that the FCFS model fits the previous simulation work and experimental data well, and thus is applicable.