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-   -   GPL hexahedral mesh tool httpwwwdiscretizerorg (

bjornthe September 20, 2007 05:24

Hello, I've done a hexahedral
I've done a hexahedral mesh program. Source will be available soon. Please have a look at the screen shots:

-Geometry creation
-OpenFOAM mesh export
-OpenFOAM case setup. (only simpleFoam/air/k-e currently)

The code is close to an alpha state. But its possible to create/read geometrys and run it instantly (if you have OpenFoam installed of course).

Björn Bergqvist

lr103476 September 20, 2007 05:47

This looks very interesting. C
This looks very interesting. Could you tell us something more about the capabilities of discretizer? I.e. which formats can it read (gambit / fluent)?, and how complex may the geometries be?

Regards, Frank

msrinath80 September 20, 2007 13:14

I agree with Frank. Is geometr
I agree with Frank. Is geometry creation like gmsh?

olesen September 21, 2007 03:07

Hi Björn, The program looks
Hi Björn,

The program looks quite interesting for constructing common cases. I'm looking forward to test driving it sometime in the future.

BTW: I like your choice of Ruby instead of Python. The syntax is clean and comfortable. But more importantly, the 'if' branches have a corresponding 'end' that really helps avoid common editting errors.

Which factors influenced your choice of Fox vs Qt (vs. wxwidgets)?


bjornthe September 22, 2007 14:22

Since it's no commercial progr
Since it's no commercial program I've made some radical design decisions:
-No geometry import. The geometry is made in Discretizer and that's it.
-Written in Ruby. Much nicer syntax than Python. Possible to use by an engineer like myself.

This geometry building is important I think. If you make a geometry in Discretizer you will force your self to think about the mesh during the geometry building phase. And since it's not a CAD program it's easy to create planes in cylindrical and spherical coordinate system. A normal CAD user would be afraid of using cylindrical/spherical coordinate system.
If you build your model in a clever way it will give you a very nice (reusable) parametric model.
Now it is purely written in Ruby. In the future I will address performance problem by writing c extensions to Ruby. The conversion between coordinate systems would probably be the first c extension, since it's quite slow.

About the choice of Fox: The GLViewer example application written by Jeroen van der Zijp was a very nice starting point for me. Also it seems like Jeroen and Lyle Johnson (FXRuby) has the right attitude (LGPL no dual licensing).

bjornthe September 23, 2007 05:38

Download: http://www.discretiz

Björn Bergqvist

vinodkgul September 25, 2007 15:26

Dear Björn Bergqvist, It wo
Dear Björn Bergqvist,

It would be nice if you could provide a typical step-by-step tutorial for discretizer. say a volume mesh over airfoil or some shape having radius, cone, cylinder etc.


hsieh September 25, 2007 21:34

Hi, The discretizer looked

The discretizer looked like a very interesting piece of code. Is it possible to build the geometry, then mesh it, then specify BCs, then finally export to OpenFOAM format?


bjornthe September 26, 2007 03:32

Hi, As for the geometry build
As for the geometry building have a look at the screencast:
I will add more high level objects in future. Like create->cube with only a point as reference.

Pei-Ying: Yes, your right. Create Geometry, apply BC:s, export to OpenFOAM, run simpleFoam and start paraView. All could be done in the interface.

Look at the release as a preview. Don't expect too much right now. Still it's quite fun to do simple geometries and just test.


armin_h October 2, 2007 00:59

Hello I am trying to make a

I am trying to make a cylinder with a small cylinder inside.
Can discretizer create that geometry?

Furthermore, how can i install taht software on my pc?

Thank you in Advance

bjornthe October 3, 2007 02:59

Hello Armin, I tried to do a
Hello Armin,
I tried to do a cylinder in a cylinder yesterday. Seems like it is possible but a bit complicated because I have not implemented higher level objects. Example of lacking functions:
-create cube between two faces.
-create face from 3 lines.

When you say pc: do you mean a pc with GNU/Linux operating system?


armin_h October 16, 2007 04:36

Hello Björn Appreciate abou
Hello Björn

Appreciate about the answer.
Actually i work with OpenFoam and i work with GNU/Linux operating system.

I am trying to create a cylinder with another cylinder inside.

I had some difficulties to that as a new openFoam User.

your information about discretizershould be so useful for me.


braennstroem July 29, 2008 03:40

Hi Bjoern, nice tool! I am
Hi Bjoern,

nice tool! I am wondering, if it is suitable for meshing the below diffuser (case 13.2):

The straight lines should be no problem, but what about the needed radii? Could this be a problem, when creating the geometry?


bjornthe August 3, 2008 15:07

Yes, it should be suitable for
Yes, it should be suitable for meshing the case 13.2 diffuser. Have a look at:

Sorry for the slow response, I've been on vacation.

Björn Bergqvist

braennstroem August 6, 2008 02:43

Hi Bjoern, thanks, though I
Hi Bjoern,

thanks, though I were not successful installing your tool on a new kubuntu, yet. I will try it again.


bjornthe August 6, 2008 12:45

I just installed discretizer w
I just installed discretizer with the following instructions on Hardy Heron 8.04 64-bit without any hassle:

Björn Bergqvist

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braennstroem August 7, 2008 13:58

Thanks, it works now! Looks in
Thanks, it works now! Looks interesting.

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