This paper presents a new module in the TELEMAC finite element modelling system: COWADIS. This software is a simplified spectral, < phase averaged » wave model dealing with wave propagation in coastal areas. After a description of some theoretical and numerical aspects, several validation test cases and industrial applications are presented. Compared to so called <∼ third generation >∼ spectral models, COWADIS reveals itself much less expensive in terms of computer memory and CPU time whereas it gives similar reliable results for much practical steady state engineering applications.
Although originally developed for deep water applications and meteorological purpose, third generation spectral "phase-averaged" wave models such as TOMAWAC (Benoit et al., 1996) have been extended towards the near shore and coastal domains. They have now proven their ability to simulate waves in near-shore areas (Moshagen et al., 1997), (Aelbrecht et al., 1998). However, this kind of models is sometimes quite demanding in terms of memory and CPU time. As a matter of fact, these shallow water domains need a fine spatial discretisation to properly represent bathymetric gradients and irregular shoreline. The use of a finite element spatial discretisation was a first major improvement for this kind of models (Benoit et al., 1996). Considering, furthermore, that steady-state simulations are sufficient for many practical engineering applications, it is possible to built a new simplified model following the approach of Holthuijsen et al. (1989). This model, named COWADIS (which stands for Computation Of Wave Action Density Integrated Spectrum), is included in the finite element TELEMAC system developed by EDF/LNH.
The so-called "third-generation" wave models does not require any parameterization of the directional wave spectrum shape, but allows the directional spectrum to develop freely both in time and space under the different physical processes concerned.
