Difference between revisions of "UNK"
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Revision as of 09:54, 13 January 2020
- 1 Basic Information
- 2 Catchwords
- 3 Short Description of Functionality
- 4 Program(s) to run before this Program
- 5 Program(s) to run after this Program
- 6 Additional Information
Name of Program
spectral wave model
action density balance equation
waves, sea, swell
refraction due to depth variation
refraction due to current variation
energy input due to wind action
nonlinear dissipation due to wave-turbulence interactions
dissipation due to wave-bottom interaction
portable SMP and SIMD programming using OpenMP
automatic determination of time-step in agreement with CFL-condition
constant alternative bathymetry depth
dynamic bathymetry depth
Acknowledgment: This project took advantage of netCDF software developed by UCAR/Unidata (www.unidata.ucar.edu/software/netcdf/).
Short Description of Functionality
Program UNK (unstructured k-model) is a post processor for different mathematical current models and can be used to compute the development, propagation and dissipation of waves, sea and swell in the ocean, coastal waters or estuaries. UNK uses as a computational core the Spectral Wave Model with Nonlinear Dissipation - K-Modell, see also literature below - which was developed at the GKSS-Forschungszentrum.
From version 7.x on UNK processes input files with alternative or dynamic bathymetry depth, the first indicating a constant depth, which differs from the rigid layer depth.
The following physical processes are currently taken into account by UNK:
- conservation of wave action density (action density balance equation);
- advection of wave action density due to currents;
- shoaling of waves due to variation of water depth and/or current velocity;
- refraction of waves due to horizontal gradients of water depth and/or current velocity;
- wind forcing at the free surface;
- dissipation due to turbulent diffusion;
- dissipation due to bottom friction.
- integral wave parameters for waves, sea and swell:
- significant wave height;
- wave peak period;
- wave mean period TM-1;
- wave period TM1;
- wave period TM2;
- wave mean direction;
- wave mean directional spread;
- acceleration (due to radiation stress).
- two-dimensional spectra for waves, sea and swell:
- frequency-direction wave spectrum.
See literature below.
Notice: further input files can be found on the file description pages of the aforementioned files.
More details concerning output files can be found on the fact sheet for filetype k_model.dat. In addition to these files the following files are also generated:
- (optional) informative printer file (Dateityp unk.sdr);
please refer to documentation/literature
Program(s) to run before this Program
Program(s) to run after this Program
- example files: please refer to $PROGHOME/examples/unk/
- Schneggenburger, C. (1998) : Spectral Wave Modelling with Nonlinear Dissipation, dissertation, 117 pages, report no. GKSS 98/E/42, GKSS-Forschungszentrum Geesthacht.
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