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keeping geometry names after import of fem

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Hi all,

I have the following problem: My model has several geometries (3 to be precise). Something went wrong (I'm not the only one developing the model, so I do not know what my colleague has done to the model, and of course she cannot explain me what she did, as she did quite a lot of stuff.) So now COMSOL (still using 3.4) gives me error at postprocessing in the first geometry - I cannot plot anything there. And only there. Everything is fine with the other two geometries. Also the problem is not with the equations themselves, because I can plot the same quantities that I have transferred to the other geometries by extrusion coupling.

I am able to work around that by exporting the model as fem structure, resetting the model and then importing the fem structure again. The problem is that in this case the geometries no longer have the names I've given to them, but are named Geom1, Geom2 and Geom3. As this is quite a complex model, with a lot of equations (some call them (multi)physics, dunno why) and later we will be adding more equations and geometries to the model, losing the names of the geometries makes the entire model hard to follow for other people and even for us.

So, my problem: why is this happening and is there a way to rename the geometries back to their original names? I know it looks like a simple question, but it's important for me.

Thank you in advance,
Stiki

1 Reply Last Post Nov 18, 2009, 3:37 p.m. EST
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Nov 18, 2009, 3:37 p.m. EST
Hi

From my knowledge you can only define the names Geom1,Geom 2, ... just as you can only define the independent x,y ... and dependent u,v,p ... variales names, as well as Physics or Application mode names smsld, smps ... when you create the items in the "Multiphysics" menu. Renameing is not possible, you need to restart in new modules.

This has for me quite some sens as there are many variables that depend on these names and once created it's not straitforward to identify all the occurances of these, including the composed names such as uxx, uxy, ut ...

When you have set up a detailed model and suddenly you detect hat you have choosen i.e 2D instead of 2D axisymmetry, and you have defined many formulas, groups etc, well you must start again .

Certian wndows allow you to save to file, Constants, Global expressions, but not Functions, nor Global equations, nor any Coupling variables etc. I agree this is frustrating but I have learned to live with it. On the other side, I do also regularly update ("save as") my models with version/revision identification as
myfile_1, myfile_2, myfile_2a, myfile_2b, myfile_3. THis eases a restart, and mostly I do a "reset" before to save such to have smaller files, but with the complexity of the meshing, and not managing to save the meshing process, this is still annoying in V3.5. This will strongly improve in V4 as we have seen with the beta.

My way around to save important functions or coupling variables is to dump, line by line, the formlas with cut&paste into text files, it takes time.

There is still the option to edit the "history file", this gives you good insight to the internals of COMSOL, you must just manage to do it correctly as the error messages are often cryptic.

For your geometries you can save them and reload them, or use cut&paste between the Geom1, Geom2 ... modes.

As an example, going from a fully constructed 2D mode to 2Daxial, you add the 2Daxial geometry, your aplication mode, you reconstruct the groups, functions ... with cut and paste (you must correct the application mode name extension if applicable) you run and when only you are happy you delete the unwanted old 2D mode.

Hope this helps
Goods luck
Ivar
Hi From my knowledge you can only define the names Geom1,Geom 2, ... just as you can only define the independent x,y ... and dependent u,v,p ... variales names, as well as Physics or Application mode names smsld, smps ... when you create the items in the "Multiphysics" menu. Renameing is not possible, you need to restart in new modules. This has for me quite some sens as there are many variables that depend on these names and once created it's not straitforward to identify all the occurances of these, including the composed names such as uxx, uxy, ut ... When you have set up a detailed model and suddenly you detect hat you have choosen i.e 2D instead of 2D axisymmetry, and you have defined many formulas, groups etc, well you must start again . Certian wndows allow you to save to file, Constants, Global expressions, but not Functions, nor Global equations, nor any Coupling variables etc. I agree this is frustrating but I have learned to live with it. On the other side, I do also regularly update ("save as") my models with version/revision identification as myfile_1, myfile_2, myfile_2a, myfile_2b, myfile_3. THis eases a restart, and mostly I do a "reset" before to save such to have smaller files, but with the complexity of the meshing, and not managing to save the meshing process, this is still annoying in V3.5. This will strongly improve in V4 as we have seen with the beta. My way around to save important functions or coupling variables is to dump, line by line, the formlas with cut&paste into text files, it takes time. There is still the option to edit the "history file", this gives you good insight to the internals of COMSOL, you must just manage to do it correctly as the error messages are often cryptic. For your geometries you can save them and reload them, or use cut&paste between the Geom1, Geom2 ... modes. As an example, going from a fully constructed 2D mode to 2Daxial, you add the 2Daxial geometry, your aplication mode, you reconstruct the groups, functions ... with cut and paste (you must correct the application mode name extension if applicable) you run and when only you are happy you delete the unwanted old 2D mode. Hope this helps Goods luck Ivar

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