SOLITARY WAVE DYNAMICS OF FILM FLOWS

The development and interaction of solitary wave pulses is critical to understanding wavy film flows on an inclined (or vertical) surface, S ufficiently far downstream, the wave structure consists of a generally irregular sequence of solitary waves independent of the conditions at the inlet. The velocity of periodic solitary waves is found to depend on their frequency and amplitude. Larger pulses travel faster; this p roperty, plus a strong inelasticity, causes larger pulses to absorb ot hers during interactions, leaving a nearly flat interface behind. Thes e wave interactions lead to the production of solitary wave trains fro m periodic small amplitude waves. The spacings between solitary waves can be irregular for several different reasons, including the amplific ation of ambient noise, and the interaction process itself. On the oth er hand, this irregularity is suppressed by the addition of periodic f orcing.