New water wave patterns found
by Yi Zhang
As reported in PhysOrg.com, French researches have found two new patterns of shallow water waves, through excitation of a Hele-Shaw tank. The complete paper at the Physics Review Letters can be found here. The following snapshots of the two waves are provided in PhysOrg.com.
Theses highly localized waves, as long as their well-known predecessors in the solitary wave family, actually are governed by very flow model, the potential flow. Their complex behaviors are rooted in the free surface motion, i.e. the change of the domain’s boundary geometries, instead of unsteady nature of the governing equations itself. The balance between the dissipation due to water viscosity and the wave dispersion characterizes such nonlinear wave motions. One feature of there two waves is the they are both steep, i.e. with high ratio between wave height and wave length, and this is the indication of high nonlinearity nature of the wave. The hysteresis we observe during the snapshots are exactly the balancing process of energy transform.