An experimental study of liquid surface oscillations in longitudinally excited compartmented cylindrical and spherical tanks

An experimental investigation of liquid surface oscillations has been conducted for liquid propellants in longitudinally excited, rigid, 90° sector cylindrical, and spherical tanks. It is determined that for longitudinal excitation, propellant motions in these tanks are basically a nonlinear l/2 subharmonic surface motion in some predominant mode, similar to the general liquid behavior that has earlier been found to occur in a rigid cylindrical tank. However, in the case of the 90° sector tank it is found that the surface shape of the predominant mode is different from that of the corresponding mode for lateral translational excitation. Stability boundaries, as well as liquid response curves are presented for two modes under various excitation conditions in each tank.