<h2>AAS 99-116</h2>
<h2>Fuel Slosh and Active Nutation Control Interaction Analysis using ellipsoidal Fuel Pendulums                                                     </h2>
<h4>S. Saeed                                                                                                                                                                            </h4>
Hughes Space & Communications, El Segundo, CA                                                                                                                             
<h2> Abstract </h2>
As more and more active control systems are used in satellite applications, the interaction between fuel slosh and active control systems becomes of greater interest. This paper develops a fuel slosh model for the cylindrishperical tank geometry using an ellipsoidal shape approximation and examines the control system/fuel slosh interaction for the active nutation control using a transverse wheel, i.e., GWANC. Linear stability results for GWANC as well as nonlinear simulations are presented. The linear stability results show that the stability margins are largely dependent on the fuel damping ratio z. With z>=1%, all of the margins are adequate for GWANC.