Modeling and Coupling Dynamics of the Spacecraft with Multiple Propellant Tanks

摘要

This paper is mainly focused on the modeling and coupling dynamics of the spacecraft with multiple propellant tanks. The dynamic boundary conditions on a curved, liquid, free surface under a low-gravity environment are transformed to general simple differential equations by using a Fourier-Bessel series expansion method, and the state vectors of coupled liquid-sloshing equations are composed by the modal coordinates of a relative potential function and the modal coordinates of the wave height. The overall coupled dynamic equations for the rigid platform motion and liquid fuel sloshing are subsequently obtained by means of Lagrange's equations in terms of general quasi coordinates. The orbit thruster firing and attitude momentum wheel controller are applied to the coupled system to testify to the mathematical model and analyze the coupling dynamics of a coupled fluid-spacecraft system. MATLAB software is used for symbolic manipulation, coupling dynamics, and control simulations. Numerical simulations via computer are carried out to validate the model derived in this paper.