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Hi!

I heard CFX-Build is going to be replaced by CAD2Mesh. What do you think about these plans?

Alexandra

Hi Alexandra,

Your comment should be past tense - CFX-Build has been replaced by CAD2Mesh. New licenses of CFX are now supplied with CAD2Mesh and you cannot get CFX-Build. Existing CFX-Build licenses will only be continued for a few months before being transferred to CAD2Mesh.

As for my comments as to whether this is good or bad, well, firstly the change over will take a significant amount of re-training. It is very different. I think CAD2Mesh is much more robust mesher when dealing with geometries imported from other CAD packages, so if you import geometries often you'll probably like it.

As for disadvantages, well CAD2Mesh is made up of two components, ANSYS DesignModeller and ICEM CFD 4.CFX. DesignModeller is a solid modelling package and ICEM is a mesh generation package. I find DesignModeller quite awkward to use if you are drawing complicated geometries. If you are drawing simple geometries it is very good.

These are just my comments as a CFX user. Maybe I'm just not used to DesignModeller yet, but I've found DesignModeller hard to use when I try to generate real geometries. I really like ICEM CFD 4.CFX however. It is a very powerful meshing package and overcomes many of the limitations of CFX-Build with dirty imported CAD geometry.

Glenn

HI Alex, I can't comment on the design modeller (yet !) but the meshing is great ! it takes a little getting used to but the mesher copes with some very poor surfaces without any sign of a complaint. We are just modelling some topography and this is made of approximately 100 surfaces. The joins between the surfaces are very poor, and I wouldn't even consider reading them into build. However the new mesher meshed it first time ! So far, I think its Great! Bob

I think you will be impressed with Design Modeler. It is by no means a replacement for your CAD tool, but they have done a great job in a short period of time to develop a geometry creation/editing tool in the Workbench interface. I use it all of the time and really like it.

Derrek

DesignModeler is a complete paradigm shift from Build and it takes some getting used to. If you've every used the free Pro/Desktop from PTC, you'll feel right at home. The methodology of creating 2D sketches and extruding these into 3D parts is identical and the interface is very similar as well. I was struggling with it at first, but I'm getting used to it.

One of the frustrations with Build was the limitation in boolean solid operations. Even the parametric solids option introduced a year ago was very clunky and didn't always make it through the mesher. DesignModeler is what Build hoped to be in this respect. I built some pretty complex geometries very quickly and they absolutely sailed through both the new ICEM-CFD-4.CFX mesher as well as the Build mesher (which will be integrated into CAD2Mesh in 2004). I simply didn't have to worry about edges, or congruency, or any of the old Build worries.

It's a shift, and a learning curve, but I think it's got far reaching benefits down the road, IMHO.

Jeff

Hi Jeff, What sorts of Geometries have you been modelling ? Has anybody tried to model a building (internal or external). ? what are your findings for something like this ? Bob

Bob,

Mine have been CPI type vessels, however....

An internal building would just be multiple blocks (rooms) separated by openings (doors), unless you're including duct work as well. There's a facility for making sure the geometries don't join as well as for placing openings on the surfaces (doors). I haven't done this myself, but it looked straight forward.

Externally, I'd buid all the buildings, then build a large environement space to cover all the buildings, and then subtract the buildings out.

Hope this helps.

Jeff

Cheers for the advice, I'll give it a go that way. Bob

Hi Bob and Jeff,

I have a question about how to create Thin Surface in CAD2MESH. CFX-Pre requires that Sub-3D is set up such that its outer surface will be assigned as Thin Surface in CFX-Pre. The problem is that when I created two Body with one containing the other, in ICEM CFD 4.CFX. I also created the Surface parts for the outer surface of the contained BODY. When I imported the mesh into CFX-Pre, the outer sufaces of the contained Body are ignored and can not be recongnized any more. So the question is how to create thin surfaces in ICEM CFD 4.CFX or ANSYS WorkBench?

Thank you very much!

Jeniffer

Jenniffer,

CFX-Pre does not require a subdomain to define a thin surface. You are confusing this with the fact that CFX-Build could not create a thin suface without a subdomain.

-Robin

Hello Robin,

Thank you for your kind response. The problem lies in the fact that CFX-Pre does not seperately recognize the internal faces which form a internal Body. All the internal faces forming a internal Body were recognized as ONE 2D-region in CFX-Pre. I have no choice to assigne different boundary conditions for each internal face of the internal body.

One solution may be creating two Body in two files, then import them seperately into CFX-Pre. However, in order to define a thin surface in CFX-Pre, the grids for the both side of a face has to be completely consistent, which is not met by the grids created in two files.

Maybe I am wrong and please give me some suggestion, Robin.

I am looking forward to your response.

Cheers,

Jeniffer