Fluid slosh studies. Volume 2: Study of slosh dynamics of fluid filled containers on slowly rotating spacecraft
Abstract
Fuel sloshing during slow rotation of spacecraft is discussed. The theory for slowly rotating spacecraft is developed completely for the threedimensional case with no rotational symmetry. Expressions for the axisymmetric case are also derived. The threedimensional problem (tanks with offset from the spin axis) is solved numerically only for spherical tanks. Tanks on the spin axis can have an arbitrary axisymmetric shape. The stability of the system is analyzed. Two cases are distinguished: dynamic instability caused by parameter combinations; and instability caused by liquid viscosity. In the dynamically instable region, the eigenfrequency of the satellite motion and of the internal rotational motion of the liquid coincide. The time constant of the dynamic instability is much smaller than the time constant for the instability caused by the energy dissipation in the boundary layer of the liquid. The control of the attitude motion of rotating systems is easier for slow spin rate because time constants of the rotational motion of the liquid depend directly on the spin rate and are large for slow rotations; and the motion of the free surface is stabilized by surface tension effects.
 Publication:

Final Report Erno Raumfahrttechnik G.m.b.H. Bremen (Germany
 Pub Date:
 November 1984
 Bibcode:
 1984ergm.rept.....E
 Keywords:

 Dynamic Structural Analysis;
 Liquid Sloshing;
 Rotating Fluids;
 Spacecraft Stability;
 Spin Stabilization;
 Boundary Value Problems;
 Fuel Tanks;
 Helmholtz Vorticity Equation;
 Three Dimensional Motion;
 Viscosity;
 Fluid Mechanics and Heat Transfer