Computation Time and Spectral Variation on Numerical Estimation for Long Wave Field in Harbors

Sufficient computation time to obtain stationary results for long wave oscillations in harbors by Boussinesq model was investigated. For different data lengths (computation times), wave spectra and significant wave heights of long waves were computed with a model harbor and several incident wave spectra. It was found that the length of the computation time to obtain stationary values are significantly influenced by frequency characteristic of amplification factor of water surface oscillations and the periods of the beats consisting of adjacent components of the incident random waves, and that the time length is generally much longer than that which is expected from random wave statistics.