Non-linear water waves - experiments and theory

The paper concems laboratory experiments on shallow water waves. The waves in our flume were generated as programmed groups, with gentle fading-in and fading-out of amplitudes of the wavemaker's piston's motions. The higher harmonic components have been considered in the motion. Their influence on characteristics of generated waves has also been studied. The measurements were carried out at 6 cross sections along the propagation path; both wave profiles and velocities were recorded. As a description of phenomena, the wave profiles were approximated by harmonic com-ponents according to the Stokes solution. It was noted, that parameters of harmonic components change along the propagation path; there are energy transfers between them. The higher harmonic components are more significant for the description of wave profiles, than for the velocities. The results of the experiments were used in verifications in a research program on the theoretical description and numerical al-gorithm for shallow water waves generated and propagated in a flume.