EFFECT OF BAFFLES ON ORBITAL ACCELERATIONS-INDUCED BUBBLE OSCILLATIONS IN MICROGRAVITY

The behavior of sloshing dynamics modulated fluid systems driven by th e orbital accelerations including gravity gradient and jitter accelera tions with partially-filled rotating fluids has been studied. Present study is applicable to a full-scale Gravity Probe-B Spacecraft dewar t ank with and without baffle. Results of slosh wave excitation along th e liquid-vapor interface induced by jitter acceleration-dominated orbi tal accelerations provide a torsional moment with an up-and-down movem ent of bubble oscillations in the rotating dewar. The results show rig htward and leftward movement of bubble oscillations transverse to the rotating axis, and up-and-down movement of bubble oscillations longitu dinal to the rotating axis of dewar container. The orbital acceleratio ns also induce an eccentric contour of bubble oscillations in a horizo ntal r-theta plane. As viscous force between liquid-solid interface, a nd surface tension force between liquid-vapor-solid interface can grea tly contribute to the damping effect of slosh wave excitation, the rot ating dewar with baffle provides more areas of liquid-solid and liquid -vapor-solid interfaces than that of a rotating dewar without baffle. Results show that the damping effect provide by a baffle reduce the am plitude of slosh wave excitation and reduce the degree of asymmetry in liquid-vapor distribution. Computation of bubble (helium vapor) mass center fluctuations also verifies that a rotating dewar with baffle pr oduces less fluctuations than that of a rotating dewar without baffle. Copyright (C) 1996 Elsevier Science Ltd.