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Description: Windfield - mesoscale nesting | Version: 4.9.0 | Updated: 10.03.09 | |
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In a default WindSim simulation the simulation area has one or two inlets and one ore two outlets. The inlet conditions are specified by log profiles. Coupled to a mesoscale meteorological model the boundary conditions are prescribed from the mesoscale model at all six boundaries of the simulation area. In- and outflow can take place at all four lateral boundaries and at the top boundary. If calculation with temperature is activated in WindSim the temperature is prescribed at all six boundaries from the mesoscale meteorological model. At the bottom boundary the in- and outflow is set to zero. The initial conditions are taken over from the mesoscale meteorological model by interpolating the results onto the WindSim grid. In the case of solving the temperature equation the temperature from the mesoscale model is used as reference temperature.
The mesoscale meteorological model does not need to have a fixed grid size. Best results are obtained if the mesoscale model has a resolution below 1 or 2 km. The nesting model must surround the current project also at the upper boundary. From the mesoscale model information about the three wind components, the pressure and the temperature is needed in an xyz format . This format has to be converted into a dws fomat. This can be done under Tools/Import mesoscale driving data. The standard folder for the xyz and the dws data is in ...\My Documents\WindSim Projects\Data\Mesoscale.
The mesoscale coupling is thought to be used to simulate common classes of weather patterns. As the number of these patterns can be quite large it may be convenient to run WindSim in batch mode to speed up the simulation process and to start simulations automatically. To run the WindSim simulations in batch mode with mesoscale driving data do the following steps:
1) Create a WindSim project and run the terrain model according to your needs
2) Set the number of cases in windfield to one and give a case number which is already available as *.dws file in the folder where you pick up the *.dws files. Edit the variables in the windfield properties according to your needs, save the project and close it.
3) Create the meteorological driving data files with the name mesofield{x} in xyz format where {x} is a number between 1 and 999 and store them in the folder you have specified in the wind field module of your project. Convert them into the dws format by using the button "Import mesoscale driving data" under tools or let them be converted automatically during the batch mode by setting the last number in the edit file to 2.
4) Edit the file edit.txt in the bin folder under the program folder according to your needs
5) Run mesocoupling_batchmode.exe in the bin folder under the program folder by doubble clicking on it.
5 i) n dos windows will pop up where you can monitor the progress of your simulations, where n is the number of jobs you want to run simultaneously. The maximum number of n which you can chose depends on the number of CPUs of your computer. Depending on the memory the maximum number may be less than the CPU number if the project is too large.
5 ii) For each of the n job queues a copy of the project is taken and the results are stored therein. After each simulation the results are updated in the project copy. The numbers in the windfield report equal to the value {x} of each simulation.
5 iii) If the simulation has determined properly the temp folder which is created during the simulation is removed from the Temp folder under WindSim projects.
In the windfield folder a info{x}.txt is printed where some values for the lower left corner of the domain are printed out which indicate if the case is stable or unstable and which friction velocity, turbulent kinetic energy and dissipation is calculated at this boundary point. Please check the size of the Farrray in CHAM.INI and in your .result file in the windfield folder. As the coupling needs a lot of memory a too small array will make the simulations stop!
The normal batch mode of WindSim needs four variables. If you run in batch mode with driving data from a mesoscale meteorological model than seven variables are added. The whole call is created automatically by a batch file when you enter all necessary information in the edit.txt file. Now the order is: windsim_core.exe var1 var2 var3 var4 var5 var6 var7 var8 var9 var10 /b /m /si%number_of_run%
The variables are:
var1 - project file (.ws) including path
var2 - layout file (.lws)
var3 - Environment.xml including path
var4 - module number you want to run e.g. 2 for the windfield
var5 - number of the specific CPU
var6 - total amount of simulations
var7 - total amount of CPUs in use
var8 - x value of the lower left mesoscale driving data field in UTM coordinates
var9 - y value of the lower left mesoscale driving data field in UTM coordinates
var10 - integer specifying if the mesoscale driving data needs to be converted
/b - run in batch mode
/m - run with mesoscale driving data
/si%number_of_run% - number of simulation in the simulation chain