Effects of Contact Line Condition on Excitation of Internal Waves Confined by a Cylindrical Wall

Standing internal waves can be excited when fluids overlaid in a stationary enclosure are subjected to harmonic, vertical oscillations. The oscillatory deformation of the fluid-fluid interface near the wall, due to the limited mobility of the fluid-fluid-wall contact line, can play an important role in the excitation of waves. The contact line may or may not move depending on the amplitude of fluid excitation. When it moves, it may do so only in a limited portion of each cycle. We analyze numerically the wave excitation associated with such nonlinear, intermittent motions of the contact line. The analytical results consistently reproduce the experimental results, and give insight into the interactions between the contact line motions and the waves on the interface.