Initial conditions

You can choose between following three different types of initial conditions:

·         Zero spectra

         the wave action is set to zero in all node points

·         Spectra from empirical formulations

         three different types of formula are available:
- JONSWAP fetch growth expression
- SPM 1973 deep water fetch growth expression
- SPM 1973 shallow water fetch growth expression

         the description of the empirical formulations can be found in Komen et al. (1994) and the Shore Protection Manual (1973, 1984)

·         Spectra from a dfsu data file

         this type can be used if e.g. you want to hotstart from a previous simulation using MIKE 21 SW

         using the fully spectral formulation, the input spectrum is the normal wave action spectrum N, e.g expressed by [m2s2/rad]

         using the directionally decoupled parametric formulation two items must be specified: the zeroth moment m0, e.g. expressed by [m2/rad], of the normal wave action spectrum and the first moment m1, e.g. expressed by [m2s/rad], of the normal wave action spec­trum.

 

When the quasi-stationary formulation is used the specified type of initial con­dition is used as the initial guess for the iterative procedure for the first time step only. For subsequent time steps the initial guess for the iterative proce­dure is based on the solution obtained from the previous time step. However, you have the option to apply the initial conditions as starting guess for the iterative procedure for all time steps. This is recommendable if you model a time series of representative independent waves.

Remarks and hints