Ogrid test. An example of how the multiline behave.



Meshing of name.

Screenshot during development of the coming extrusion feature.

Geometry modification + mesh creation + CFD simulation in one command!

File modified from commandline

Now it's possible to modify geometry file from command line. The "-exec" flag makes Discretizer run in batch mode (no GUI) and executes the simulation, then quits (OpenFOAM 1.4 installation required obviously).

Usage: discretizer "dtz-file" "row"/"parameter"/"value" (-exec)
Example: discretizer opti001.dtz 8/yvec/90 9/yvec/110 10/yvec/170 11/yvec/210 -exec

This would then execute 2 simulations with different geometry:
#!/bin/sh
discretizer opti001.dtz 8/yvec/60 9/yvec/110 10/yvec/160 11/yvec/200 -exec
sh postprocess.sh opti001 run001.txt
discretizer opti001.dtz 8/yvec/50 9/yvec/100 10/yvec/150 11/yvec/200 -exec
sh postprocess.sh opti001 run002.txt

Script and geometry file included in the optimization directory when downloaded from SVN.

SVN instructions
This project's SourceForge.net Subversion repository can be checked out through SVN with the following instruction set:

svn co https://discretizer.svn.sourceforge.net/svnroot/discretizer discretizer

A long CFD screencast

I wanted to look at the influence of static pressure when decreasing the cross section of a pipe in different ways. Discovered that it was fun to use Discretizer so I made a screencast out of it:
Design looping in Discretizer in this screencast. A pictures of steps involved shown here.

Discretizer in action

Example geometry.

Discretizer on Vista

After installing a new driver (ATI Catalyst 8.5), OpenGL speed was fast. OpenGL with Catalyst 7.4 was unacceptable slow.

A pipe bend example

ParaView visualization of pipe bend.

Discretizer model view

OpenGL speed enhancement

Now it's possible to view bigger models with a high frame rate. Selection is also more rapid. This was achevied by the use of OpenGL display lists. Huge improvement. Currently only available via sourceforge SVN.


The 1,200,000 cell corkscrew is now editable thanks to the enormous OpenGL speed encrease. Time to read the file is now only less than 10 minutes compared to the 1.5 hours before. Number of surface cells on display is 49x49x2+ 49x499x4 = 102,606

Big mesh test

To really test the new mesh creation speed I increased the number of cells in the "t20_screw.dtz"-file to 50x50x500 nodes (1,198,099 cells). It took 1.5 h to read the file, 6 hours to create the volume mesh and 14 hours to calculate 100 iterations with simpleFoam. The volume mesh speed took much longer time because the computer did a lot of swapping (an ancient Pentium4 2.4 GHz with 1.5 GB RAM). Y-plus is about 30 in this calculation.

Model of flow over cylinder.

Geometry file opened.



Inlet boundary assigned.



Pressure outlet.



Run dialog.



ParaView postprocessing.

Try it out: Download

Feb 22, 2009