Dolfyn is controlled by an input deck (with extension .din). This file is a simple ascii file and can be created and/or edited by any ascii editor. In order to make your life easier a dedicated programm has been written just for this task. Orka is written in python (see www.python.org ) and uses the Tkinter interface to the Tcl/Tk . The combination of python and tkinter is platform independent and runs on any platform where python is installed (standard with Linux).
This is the first 'preview release' of orka. This version has been tested mainly under Linux. Please check the -not yet implemented- 'prefereces' at the end of the orka.py script and set the following variables to your own environment: OrkaPath, Orka, Editor, DolfynPath and Dolfyn. Further enhancements and help is welcome at 'info (a kind of a) dolfyn.net'.
Screenshots from orka in action:
The convention on this page is: red the commands as you type them ('$' is the command line prompt), in blue the output. Moreover, click on an image for a larger picture!
Download the source:
2a. Install (Unix/Linux)
Unpack the file (eg. in the directory where the dolfyn binary lives):
$ tar xvozf orka_mrt2006.tgz
One way to start orka is to call python with:
$ python orka.py &
In the 'file' menu start with 'New...' and enter a case name.
2b. Install (Windows)
If not already installed, first download the python environment using www.python.org/windows and click 'Download Python for Windows'. Please follow the procedures described there.
Unpack the orka tar-file with WinZip or a similar tool (eg. in the directory where the dolfyn binary lives). No additional effort should be necessary (Tkinter is part of the default installation). In the Windows Explorer you should be able to click on the orka.py icon and start the script.
3. Examples of panels and usage
After a new case has been enter, go to the 'Run menu' and select 'Parameters'. The following panels are available:
- General settings
- Fluid properties
- Initial conditions
- Numerical controls
- Boundary conditions
In the 'General settings' panel the basic control parameters are grouped together:
- Case title (a descriptive title of the case)
- Time mode (steady state or transient)
- Iterations (how many iterations for the next run)
- Restart (None, Restart, Reset or Initial field)
The 'Advanced' button gives some extra, mainly debug output, options.
In the 'Fluid properties' panel the main fluid properties are grouped together:
- Laminar viscosity
- Turbulence (Off or Standard k-epsilon)
- Thermal (Off or On)
- Various thermal properties (only if thermal mode is selected)
- The pressure reference and monitor cells
In the 'Initial conditions' panel the initial values for the primitive variabels are grouped together:
Then you might proceed to the 'Numerical controls' panel for the various relaxation and blending factors:
The 'Advanced' button gives some extra, rarely used, options.
Now the major settings are complete the next step is to enter the boundary conditions in the 'Boundary conditions' panel:
For every boundary region click the 'Add Region' button and enter the number. Remember
any unassigned boundary will be labeled to zero (0) by the preprocessor, so in general a
region 0 is required. Boundary regions do not have to be consequtive so, for example, region
'0', '1', '9' and '22' is valid.
The following boudary conditions are currently supported:
- Wall (Noslip, Slip)
- Symmetry plane
In the 'Postprocessing' panel the postprocessing options are collected. Choose your own interface (OpenDX, VTK):
Finally hit 'Apply' and the din-file will be written. Next dolfyn might be started:
Remember to save the orka database. The 'Reset' button reload the settings from the stored database. The 'Cancel' button simply closes the 'Parameters panel' and does not undo the latest entries (use 'Reset' instead).
Warning! You need to know what to do. The codes and files are 'as is'. The software and files are there to give you an impression only without any guarantee whatsoever. Accompanying documentation is (still) unavailable.
Everything here is still under heavy development. Updates and changes are not ruled out; in matter of fact, expected.