Combined gravity gradient and jitter accelerations acting on liquid-vapor interface oscillations in reduced gravity (Q1905611)

The authors investigate the dynamical behaviour of fluids affected by the asymmetric combined gravity gradient and jitter accelerations, in particular the effect of surface tension on partially filled rotating fluid in a spacecraft Dewar tank. Three different cases of accelerations are studied: (i) when gravity gradient dominates; (ii) when gravity gradient and jitter gradient are of the same order; (iii) when jitter gradient dominates. It is observed that the sloshing wave excitation along the liquid-vapor interface induced by the gravity gradient-dominated acceleration is equivalent to the combined effect of a twisting force and a torsional moment acting on the spacecraft. Next, the sloshing wave excitation along the liquid vapor interface induced by the jitter-dominated acceleration is equivalent to time-dependent oscillatory forces which push the bubble in all directions as the bubble rotates about the Dewar axis. The sloshing wave excitation along the liquid vapor interface driven by the combined effect of gravity gradient and jitter acceleration (which are two major forces affecting the stability of the fluid system in microgravity) is also clarified through the text.