CGWAVE: A Coastal Surface Water Wave Model of the Mild Slope Equation.

This report describes a new wave-prediction model called CGWAVE. CGWAVE is a genetal-purpose, state-of-the-art wave prediction model. It is applicable to estimation of wave fields in harbors, open coastal regions, coastal inlets, around islands, and around fixed or floating structures. Both monochromatic and spectral waves can be simulated with the CGWAVE model. While CGWAVE simulates the combined effects of wave refraction-diffraction included in the basic mild-slope equation, it also includes the effects of wave dissipation by friction, breaking, nonlinear amplitude dispersion, and harbor entrance losses. CGWAVE is a finite-element model that is interfaced to the Corps of Engineers Surface-water Modeling System SMS for graphics and efficient implementation pre-processing and post-processing. The classical super-element technique and a new parabolic approximation method developed recently are used to treat the open-boundary condition. An iterative procedure conjugate gradient method is used to solve the discretized equations, thus enabling the modeler to deal with large-domain problems. A detailed derivation of the basic theory of the CGWAVE model is provided in Sections 2 and 3. Sections 4 through 6 provide the details of how this theory is implemented numerically. A step-by-step users guide is provided in Section 7 to ensure safe and efficient usage of the CGWAVE model for practical applications. Example applications used in the development, testing, and validation of CGWAVE are presented in Section 8 of this report.