-A nonlinear model of mean free surface of waves or wave set-up is presented.The model isbased on that of Roelvink(1993),but the numerical techniques used in the solution are based on theWeighted-Average Flux(WAF)method(Watson et al,1992),with Time-Operator-Splitting(TOS)usedfor the treatment of the source terms.This method allows a small number of computational points to beused,and is particularly efficient in modeling wave set-up.The short wave(or primary wave)energy equa-tion is solved by use of a more traditional Lax-Wendroff technique.A nonlinear wave theory(James,1974)is introduced.The model described in this paper is found to be satisfactory in most respects whencompared with the measurements conducted by Stive(1983)except in modeling the mean free surface veryclose to the mean shoreline.
A narrow open channel resonant phenomenon, newly found by the authors in corresponding numerical calculations , was proved to exist based on the method of matching asymptotic expansions for three different channel configurations. It is shown that the resonant wave numbe rk emerges around kL=nπ, n=1,2,3,…∞ with a corresponding frequency s hift, where L is the length of the channel. It is also clear that the resona nce in a narrow open channel is an essential property of a channel as long as it is uniformly narrow.
Miao Guo-ping (School of Naval Architecture and Ocean Engineering, Shanghai Jiaot ong University, Shanghai 200030, China) H.Ishida, T.Saitoh (Department of Civil Engineering, Kanazawa University, Japan)
A numerical model of low frequency waves is presented. The model is based on that of Roelvink (1993), but the numerical techniques used in the solution are based on the so-called Weighted-Average Flux (WAF) method withTime-Operator-Splitting (TOS) used for the treatment of the source terms. This method allows a small number ofcomputational points to be used, and is particularly efficient in modeling wave setup. The short wave (or primary wave)energy equation is solved with a traditional Lax-Wendroff technique. A nonlinear wave theory is introduced. The modeldescribed in this paper is found to be satisfactory in modeling low frequency waves associated with incident bichromaticwaves.
