Shock wave criterion for propagating solitary states in driven surface waves

O. Lioubashevski and J. Fineberg

The Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel

Received 12 November 2000; published 13 February 2001

Highly localized solitary states are observed to propagate along the surface of a thin two-dimensional fluid layer. The states are driven by means of a spatially uniform, temporally periodic, vertical acceleration (Faraday experiment) in a highly dissipative fluid. These states are shown to be formed by coupled fronts that propagate, periodically, as shock waves. A criterion for their formation based on shock initiation is presented. Both the characteristic form and interaction dynamics of the solitary states can be understood in this picture.