Generation of focalized wave packet.

Abstract : The generation of focalized wave packets is studied both experimentally and numerically. The exper- imental campaign is carried out in the wave flume of Ecole Centrale Marseille. The purpose is to experimentally generate the focalisation of wave close to a vertical wall thus yielding a database for numerical tools. Two numerical approaches are investigated. The theoretical framework is potential theory. On one hand Boussinesq equations are solved. Boussinesq model is suitable to propagate adequately a wave packet by accounting for most nonlinearities of the gravity wave. From that model, initial conditions are extracted and introduced in a fully nonlinear wave model. The present abstract shows some results illustrating the techniques developed and their validations. Difficulties to reproduce numerically the fine details of the measured overturning crest at the vertical wall are discussed.