Print Email Facebook Twitter Dynamics and control of a spacecraft with a moving, pulsating ball in a spherical cavity Title Dynamics and control of a spacecraft with a moving, pulsating ball in a spherical cavity Author Vreeburg, J.P.B. Institution National Aerospace Laboratory NLR Date 1996-09-27 Abstract A model with two interacting bodies, for a spacecraft with liquid, has been developed. The spacecraft without liquid is the "tank" and is characterized by its inertial properties and the location and size of a spherical cavity. In the cavity is located the "slug", a sphere of uniform density with a variable radius. At the point of contact between slug and tank the interaction force and torque are prescribed as a function of liquid properties and state variables. The model is named SMS, for Sloshsat Motion Simulator. Its initial objective is to support the development of control laws for the Sloshsat spacecraft, presently under development and scheduled to be launched in 1998. Sloshsat is to perform a series of experiments for the validation of CFD models of spacecraft with onboard liquid. The SMS parameters are to be predicted by CFD simulations and finally to be validated by Sloshsat results. The special feature of SMS is the variable size of the slug. It provides a degree of freedom for the modelling of the variable shape of onboard liquid. The dynamic behaviour of SMS is illustrated and discussed for some particular cases, including a PAM-D nutation model. Control of SMS is evaluated for commanded uniform rotation about its intermediate principal axis and stabilized by a cold-gas jet system with 12 nozzles. The cavity centre is on the axis of rotation but not at the centre of mass of the tank. Although the tank is easily stabilized by its reaction control system, a very small friction between slug and tank causes angular momentxim to accumulate in the slug motion and results in large oscillations of size. Subject computerized simulationdynamic modelsequations of motionliquid sloshingliquid filled shellsmotion stabilitynutationrotating spheresslagsspacecraft stabilityspacecraft controltanks (containers) To reference this document use: http://resolver.tudelft.nl/uuid:5acd812f-6c2a-4266-8a8c-1c86b4103be9 Publisher Nationaal Lucht- en Ruimtevaartlaboratorium Access restriction Campus only Source NLR Technical Publication TP 96564 U Part of collection Aerospace Engineering Reports Document type report Rights (c) 1996 National Aerospace Laboratory NLR Files PDF 96564.pdf 17.5 MB Close viewer /islandora/object/uuid:5acd812f-6c2a-4266-8a8c-1c86b4103be9/datastream/OBJ/view