Comparisons of Numerical Random Sea Simulations

Two numerical models previously developed by Rice for modeling Gaussian, white-noise, electronic signals are used to simulate in the frequency domain nonlinear random ocean waves in water of finite depth. The following two models were developed by Rice: (1) Nondeterministic Spectral Amplitude model (NSA), and (2) Deterministic Spectral Amplitude model (DSA). These two Rice models are used with finite Fourier transform (FFT) algorithm to simulate linear Gaussian random wave realizations by the process of filtering Gaussian white noise in the frequency domain. A nonlinear random wave interaction matrix then operates on the linear Gaussian wave spectra to generate a complex-valued nonlinear random wave spectrum that is correct to second-order in the Stoke's wave perturbation parameter. Both the lineear and the nonlinear realizations obtained from both of Rice's two simulation models are compared with a realization obtained from hurricane-generated real ocean waves measured in the Gulf of Mexico. Statistical comparisons indicate that the NSA Rice model is better for both linear and nonlinear random wave simulations when band-limited white noise is digitally filtered.