PROJect 'name' 'nr' 'title1' 'title2' 'title3'
With this required command the user defines a number of strings to identify the SWAN run (project name
e.g., an engineering project) in the print and plot file.
'name' | is the name of the project, at most 16 characters long. | |
Default: blanks. | ||
'nr' | is the run identification (to be provided as a character string; e.g. the run | |
number) to distinguish this run among other runs for the same project; it is at | ||
most 4 characters long. It is the only required information in this command. | ||
'title1' | is a string of at most 72 characters provided by the user to appear in the | |
output of the program for the user's convenience. | ||
Default: blanks. | ||
'title2' | same as 'title1'. | |
'title3' | same as 'title1'. |
SET [level] [nor] [depmin] [maxmes] [maxerr] [grav] [rho] [cdcap] & | NAUTical | [inrhog] [hsrerr] < > [pwtail] [froudmax] | -> CARTesian |
With this optional command the user assigns values to various general parameters.
[level] | increase in water level that is constant in space and time can be given with | |
this option, [level] is the value of this increase (in m). For a variable water | ||
level reference is made to the commands INPGRID and READINP. | ||
Default: [level]=0. | ||
[nor] | direction of North with respect to the x -axis (measured counterclockwise); | |
default [nor]= 90 ^{o}, i.e. x -axis of the problem coordinate system | ||
points East. | ||
When spherical coordinates are used (see command COORD) the value | ||
of [nor] may not be modified. | ||
[depmin] | threshold depth (in m). In the computation any positive depth smaller than | |
[depmin] is made equal to [depmin]. | ||
Default: [depmin] = 0.05. | ||
[maxmes] | maximum number of error messages (not necessarily the number of errors!) | |
during the computation at which the computation is terminated. During the | ||
computational process messages are written to the print file. | ||
Default: [maxmes] = 200. | ||
[maxerr] | during pre-processing SWAN checks input data. Depending on the severity | |
of the errors encountered during this pre-processing, SWAN does not start | ||
computations. The user can influence the error level above which SWAN will | ||
not start computations (at the level indicated the computations will continue). | ||
The error level [maxerr] is coded as follows: | ||
1 : warnings, | ||
2 : errors (possibly automatically repaired or repairable by SWAN), | ||
3 : severe errors. | ||
Default: [maxerr] = 1. | ||
[grav] | is the gravitational acceleration (in m/s^{2}). | |
Default: [grav] = 9.81. | ||
[rho] | is the water density (in kg/m^{3}). | |
Default: [rho] = 1025. | ||
[cdcap] | is the maximum value for the wind drag coefficient. A value of [cdcap] = 99999 | |
means no cutting off the drag coefficient. A suggestion for this parameter is | ||
[cdcap] = 2.5x 10^{-3}. | ||
Default: [cdcap] = 99999. | ||
[inrhog] | to indicate whether the user requires output based on variance or based on true | |
energy (see Section 2.5). | ||
[inrhog] = 0 : output based on variance | ||
[inrhog] = 1 : output based on true energy | ||
Default: [inrhog] = 0. | ||
[hsrerr] | the relative difference between the user imposed significant wave height and the | |
significant wave height computed by SWAN (anywhere along the computational | ||
grid boundary) above which a warning will be given. This relative difference | ||
is the difference normalized with the user provided significant wave height. This | ||
warning will be given for each boundary grid point where the problem occurs | ||
(with its x - and y -index number of the computational grid). The cause of the | ||
difference is explained in Section 2.6.3. To supress these warnings (in particular | ||
for nonstationary computations), set [hsrerr] at a very high value or use | ||
command OFF BNDCHK. | ||
Default: [hsrerr] = 0.10. | ||
ONLY MEANT FOR STRUCTURED GRIDS. | ||
NAUTICAL | indicates that the Nautical convention for wind and wave direction (SWAN input | |
and output) will be used instead of the default Cartesian convention. | ||
For definition, see Section 2.5 or Appendix A. | ||
CARTESIAN | indicates that the Cartesian convention for wind and wave direction (SWAN input | |
and output) will be used. For definition, see Section 2.5 or Appendix A. | ||
[pwtail] | power of high frequency tail; defines the shape of the spectral tail above the | |
highest prognostic frequency [fhigh] (see command CGRID). The energy density | ||
is assumed to be proportional to frequency to the power [pwtail]. | ||
Default values depend on formulations of physics: | ||
command GEN1 : [pwtail] = 5 | ||
command GEN2 : [pwtail] = 5 | ||
command GEN3 KOMEN : [pwtail] = 4 | ||
command GEN3 JANSSEN : [pwtail] = 5 | ||
If the user wishes to use another value, then this SET command should be | ||
located in the command file after the GEN1, GEN 2 or GEN3 command | ||
(these will override the SET command with respect to [pwtail]). | ||
[froudmax] | is the maximum Froude number ( U/ with U the current and d the water | |
depth). The currents taken from a circulation model may mismatch with given | ||
water depth d in the sense that the Froude number becomes larger than 1. | ||
For this, the current velocities will be maximized by Froude number times . | ||
Default: [froudmax] = 0.8. |
|-> STATionary | |-> TWODimensional | MODE < > < > | NONSTationary | | ONEDimensional |
With this optional command the user indicates that the run will be either stationary or nonstationary and one-dimensional (1D-mode) or two-dimensional (2D-mode). Non-stationary means either (see command COMPUTE):
| -> CARTesian | COORDINATES < | -> CCM | > REPeating | SPHErical < > | | QC |
Command to choose between Cartesian and spherical coordinates (see Section 2.5).
A nested SWAN run must use the same coordinate system as the coarse grid SWAN run.
CARTESIAN | all locations and distances are in m. Coordinates are given with respect | |
to x - and y -axes chosen by the user in the various commands. | ||
SPHERICAL | all coordinates of locations and geographical grid sizes are given in degrees; | |
x is longitude with x = 0 being the Greenwich meridian and x > 0 is East of | ||
this meridian; y is latitude with y > 0 being the Northern hemisphere. Input | ||
and output grids have to be oriented with their x -axis to the East; mesh sizes | ||
are in degrees. All other distances are in meters. | ||
CCM | defines the projection method in case of spherical coordinates. CCM means | |
central conformal Mercator. The horizontal and vertical scales are uniform | ||
in terms of cm/degree over the area shown. In the centre of the scale is | ||
identical to that of the conventional Mercator projection (but only at that | ||
centre). The area in the projection centre is therefore exactly conformal. | ||
QC | the projection method is quasi-cartesian, i.e. the horizontal and vertical scales | |
are equal to one another in terms of cm/degree. | ||
REPEATING | this option is only for academic cases. It means that wave energy leaving at one | |
end of the domain (in computational x -direction) enter at the other side; it is | ||
as if the wave field repeats itself in x -direction with the length of the domain | ||
in x -direction. | ||
This option cannot be used in combination with computation of set-up (see | ||
command SETUP). This option is available only with regular grids. |