Wave field generation with controlled instantaneous and spectral statistics

The need to generate random wave fields with a pre-determined spectrum is a common one. One of the typical applications requiring this capability is the need to interface spectral and deterministic models. The spectra and integral parameters produced as output of spectral models must often be transformed into wave fields which can be used as input to deterministic models (e.g. Navier-Stokes based numerical models). Also, the instantaneous statistics of the produced wave field must be controlled. This is typically the case when the objective is to evaluate the influence of these statistics in the appearance of certain wave phenomena. In this article we propose a parametric based approach to the wave field generation. Not only is this a computationally efficient way of generating local elevation sequences, but it also enables perfect control of both the instantaneous and spectral characteristics of the generated waves. Two examples of applications will be given. One, where the developed generator will be used to investigate the influence of the spectral model and the instantaneous statistics of the wave field in extreme wave generation. A second example will be the generation of a boundary field for a Navier-Stokes based model starting from the spectral output of the SWAM model.