E. Soewono

We consider here low amplitude wave groups for nonlinear model arising in hydrodynamic laboratory experiment for wave generation. Such waves may be produced in a repetition of movement of wave makers resulting regular waves of nearly the same frequencies. The model equation being used which suits the laboratory condition is the Korteweg-de Vries with improved (exact) dispersion w = k . A second order expansion is used to generate wave groups, starting from the Fourier integral form for the linearized dispersive equation and added by the second order integral form obtained from the first iterative nonlinear solution. Analytical description of interaction of solitary type wave groups based on couple NLS type amplitude equations is shown here.