Rogue Wave Statistics and Dynamics Using Large-Scale Direct Nonlinear Wavefield Simulations

We study the occurrence and dynamics of rogue/freak waves using large-scale three-dimensional nonlinear phase-resolved wavefield simulations. The outcome of this research will establish the foundation for effective tools for prediction of the occurrence and dynamics of rogue wave events in realistic ocean environments. The main research objectives are to: (I) obtain a significant number of representative large-scale rogue wave datasets using direct simulations; (II) verify the validity and limitations of existing theories and models for the statistics of large-amplitude wavefields and the occurrence of rogue wave; and (III) understand the fundamental mechanisms for rogue wave development. Of particular importance is to validate (or invalidate) the hypotheses and assumptions underlying the existing theories, statistics and models/tools for rogue wave prediction.

This research is made possible by the availability, for the first time in recent years, of highly efficient large-scale direct phase-resolved nonlinear wave simulations on parallel computing platforms. These direct simulations are based on a high-order spectral method using Zakharov-equation/mode-coupling idea and accounting for nonlinear wave interactions up to an arbitrary high order. The method obtains linear computational effort and exponential convergence with respect to number of wave modes and nonlinear order and is not limited by the broad bandwidth or directional spreading of the wave spectrum. This phase-resolved approach also provides the framework for inclusion of direct physics-based models for physical effects such as bathymetry, variable current, wind input, and wave breaking.