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 Python powered 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:

Orka / Windows Orka / Linux

This page has the following sections:
1. Download
2a. Install (Unix/Linux)
2b. Install (Windows)
3. Examples of panels and usage

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!

1. Download

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:

In the 'General settings' panel the basic control parameters are grouped together:

General settings

The 'Advanced' button gives some extra, mainly debug output, options.

In the 'Fluid properties' panel the main fluid properties are grouped together:

Fluid properties

In the 'Initial conditions' panel the initial values for the primitive variabels are grouped together:

Initial conditions

Then you might proceed to the 'Numerical controls' panel for the various relaxation and blending factors:

Numerical controls

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:

Boundary conditions

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:

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.

Cyclone www.dolfyn.net