Structure of Frequency Domain Models for Random Wave Breaking

摘要

We consider the form of a breaking wave dissipation term for use in spectral orstochastic wave evolution models. A time domain Boussinesq model is tested for accuracy in modeling evolution of second and third moment statistics in shoaling and breaking waves. The structure of the dissipation term in the time domain is then used to infer the corresponding structure of the term in the frequency domain. In general, we find that the dissipation coefficient is distributed like 1/Sn(f), where Sn(f)is the spectral density of the surface displacement n. This implies an f2 dependence for the coefficient in the inner surfzone, as opposed to a constant distribution over frequency as suggested by Eldeberky and Battjes (1996).