SHIP WAVES GENERATED BY A CRUISE SHIP: FIELD OBSERVATION AND NUMERICAL REPRESENTATION USING GREEN'S FUNCTIONS

Along fairways, rivers, and sheltered seas, ship waves may have dominant influence on shore and bank erosion and disturb the ecosystem (e.g., Larson et al. 2017, Almström et al., 2022). For efficient and reliable prediction of ship wave generation, the authors developed a numerical model based on Green’s functions (Morioka et al., 2020). While reasonably good model performance was confirmed through comparison with measured data in a laboratory experiment, observed ship waves, generated by a relatively small model boat, were dominated by secondary wave components with relatively short periods. Model applicability for prediction of primary wave components, dominantly generated by a large vessel, was not established. Primary waves are induced by the pressure head drop around a vessel, whereas secondary waves are generated through water surface disturbances induced around the bow and the stern. Differences in the physical mechanisms of these two wave components make it difficult for a model to represent both components using a simple unified methodology. This study presents results from a unique field survey of ship waves generated by a cruise ship along a sheltered coastal fairway in Sweden, including the application and enhancements of the aforementioned model, which improved predictions of both the observed primary and secondary ship wave components.