A Computation Method for the Typhoon Waves Using the Field Wave Spectrum

Abstract

Wave features and propagation characteristics during typhoons are the key factors to study the dynamic response of ocean engineering and coastal disaster prevention and mitigation under extreme climate. Based on the Longuet-Higgins theory, the method of the field spectrum during the typhoon was used to compute the typhoon waves. And the directional spectrum, the formulas of wave surface, the velocity of water particles, and the acceleration of water particles were investigated. The results showed that the interpolated field wave spectrum combined with the SWOP direction spectrum could accurately simulate the three-dimensional typhoon waves. The significant wave height and the average period of the simulated wave surface at fixed point were statistically evaluated by the upward zero-crossing method, and the relative errors were ± 5% and ± 15%, respectively. The typhoon wave surface computed by a dual peak spectrum had small periodic waves, and the velocity and acceleration of water particles differed considerably from the JONSWAP spectrum. Finally, a fastened slender cylinder was simulated under action of the typhoon waves, which proved the applicability of the computation method. This study aims at providing a basis for the simulation of the dynamic response of marine structures under the typhoon waves action.