Bruce Denardo
Dept. of Phys. and Astron., Univ. of Mississippi, University, MS 38677
Ali Kolaini
Natl. Ctr. for Physical Acoust., University, MS 38677
It has been predicted that an acoustic breather soliton can exist in a rigid-wall waveguide filled with a liquid [Aranha et al., J. Fluid Mech. 121, 465--485 (1982)]. This is a propagating nonlinear wave whose particle motion is primarily perpendicular to the waveguide, and whose amplitude is exponentially self-localized along the waveguide. The wave is mathematically described to lowest order by a nonlinear Schrodinger equation. If a transverse mode of the waveguide is driven at one end at a frequency below cutoff and with a sufficiently large amplitude, it is also predicted that the solitons will be spontaneously ejected at a periodic rate. Current attempts to observe the acoustic soliton in a long tube filled with water will be described. The existence of the solitons and ejection process in other physical systems will also be described.