Two types of wave-current interactions and their effects on extreme waves in directional seas

The nonlinear wave-current interactions can influence and change extreme wave probability, spectral charac-teristics, and average shape of extreme waves significantly (Wang, J., Ma, Q. W., & Yan, S. (2021). On Extreme Waves in Directional Seas with Presence of Oblique Current. Applied Ocean Research, 112, pp. 102586). There are different scenarios of wave-wave interactions in reality. This study identifies two types of wave-current in-teractions: Type-I (waves propagating from current-negligible region to current-significant region) and Type-II (waves propagating from current-significant region to current-negligible region). The impacts of the two types of wave-current interactions on extreme wave probability and the spectral properties will be investigated by using fully nonlinear potential flow model. The numerical results reveal that the changes in extreme wave probability and spectral properties due to Type-I are more evident than those induced by Type-II. It is recom-mended that a proper type of wave-current interaction scenario should be selected in the design of the numerical modelling or laboratory experiments for wave-structure interactions to achieve more accurate representations of the local wave climate and flow conditions.