On the structure of artificially generated water wave trains

The structure of an artificially generated sinusoidal water wave train of fixed frequency under the influence of wind is analyzed. Artificially generated waves of 1 Hz are studied at seven wind speeds in the range of 140-400 cm/s. It is observed that the water wave train deformed by wind consists of two components at both the fundamental mode and the harmonics. The amplitude and phase of the wave components are derived, and the dispersion relation and component phase speeds are examined. The data reveal that the amplitude of the forced and free-traveling second harmonics correlate with previous theories, and that the deviation of the measured phase speed from the linear theory is caused by the nonlinearity of the primary wave, the interaction between short gravity waves and the primary wave, and the advection effects of wind drift.