Dept. of Phys. and Astron., Univ. of Mississippi, University, MS 38677
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.