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Geometry arrays
Posted Feb 3, 2011, 6:01 p.m. EST Geometry Version 4.0a, Version 4.4, Version 5.2 5 Replies
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Hey guys, quick modeling question.
I'm using 4.0a, and I have a geometrical array (so, a repeated number of blocks) whose number of elements (size) is a parameter. If I increase the parameter, I get more elements, and so on. First off, I want to make the entire array, regardless of the parameter, part of the same union. It seems to me that it's impossible to add the whole array to a union instead of individual elements (of if there is a way I haven't found it).
Secondly, I'd like to have any new elements created by changing the size parameter to share the boundary conditions and subdomain physics as the rest of the elements. This way I can run a parametric study without stopping after every run and adding the same boundary conditions over and over.
If anyone knows how to do any of this it would be a great help.
- Dave
I'm using 4.0a, and I have a geometrical array (so, a repeated number of blocks) whose number of elements (size) is a parameter. If I increase the parameter, I get more elements, and so on. First off, I want to make the entire array, regardless of the parameter, part of the same union. It seems to me that it's impossible to add the whole array to a union instead of individual elements (of if there is a way I haven't found it).
Secondly, I'd like to have any new elements created by changing the size parameter to share the boundary conditions and subdomain physics as the rest of the elements. This way I can run a parametric study without stopping after every run and adding the same boundary conditions over and over.
If anyone knows how to do any of this it would be a great help.
- Dave
5 Replies Last Post Nov 25, 2016, 9:50 a.m. EST
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Posted:
1 decade ago
Hi
I'm not sure what to propose, but a few comments:
I have noticed that COMSOL has managed to improve the way they consider geoemtrical "heritage" from earleir 3.5 version, and that this has been further improved in the latest (4.1 version compared to the early 4.0).
But, changing the number of elements in a model is a "topology change". And it's difficult for a programme (even for COMSOL) to guess right what you want.
Perhaps though, if you start with the maximum number of items, define all BC, and then decrease the number of eleemnts in your array, then the heritage will work better. But this is a pure "guess" from my side and I do not have access to COSMOL just now, to chekcit out, but worth a try both ways.
--
Good luck
Ivar
I'm not sure what to propose, but a few comments:
I have noticed that COMSOL has managed to improve the way they consider geoemtrical "heritage" from earleir 3.5 version, and that this has been further improved in the latest (4.1 version compared to the early 4.0).
But, changing the number of elements in a model is a "topology change". And it's difficult for a programme (even for COMSOL) to guess right what you want.
Perhaps though, if you start with the maximum number of items, define all BC, and then decrease the number of eleemnts in your array, then the heritage will work better. But this is a pure "guess" from my side and I do not have access to COSMOL just now, to chekcit out, but worth a try both ways.
--
Good luck
Ivar
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Posted:
1 decade ago
Hi Ivar,
I tried that, they don't keep boundary or subdomain conditions when you preset them and then change the number of array elements. Perhaps this is something you can add for the next version?
- Dave
I tried that, they don't keep boundary or subdomain conditions when you preset them and then change the number of array elements. Perhaps this is something you can add for the next version?
- Dave
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Posted:
1 decade ago
Hi
well I cannot add anything to COMSOL, as I'm just a plain user as you, not linked to COMSOL inc, apart that I'm a fan of the programme, it so fun to do physics again with such a tool !
However, if you could think of a good way to decide how to allow COMSOL to heritate info when adding or changing the topology then I believe the developpers would be very interested to hear about it.
--
Good luck
Ivar
well I cannot add anything to COMSOL, as I'm just a plain user as you, not linked to COMSOL inc, apart that I'm a fan of the programme, it so fun to do physics again with such a tool !
However, if you could think of a good way to decide how to allow COMSOL to heritate info when adding or changing the topology then I believe the developpers would be very interested to hear about it.
--
Good luck
Ivar
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Posted:
1 decade ago
Hey guys, quick modeling question.
I'm using 4.0a, and I have a geometrical array (so, a repeated number of blocks) whose number of elements (size) is a parameter. If I increase the parameter, I get more elements, and so on. First off, I want to make the entire array, regardless of the parameter, part of the same union. It seems to me that it's impossible to add the whole array to a union instead of individual elements (of if there is a way I haven't found it).
Although this is an old post, I'm experiencing the same problem. Here is my solution in 4.4:
In the Geometry/Array properties, check the "create selection" under the "selections of resulting entities",
then make a new selection, name it "SelectionArray" (or something you like).
Next, create a union. Swith the "input objects" from Manual to "SelectionArray". This way all elements of the original array contribute to the union, regardless of the parameter settings.
Hopes that will help.
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Posted:
9 years ago
Although this is an old post, I'm experiencing the same problem. Here is my solution in 4.4:
In the Geometry/Array properties, check the "create selection" under the "selections of resulting entities",
then make a new selection, name it "SelectionArray" (or something you like).
Next, create a union. Swith the "input objects" from Manual to "SelectionArray". This way all elements of the original array contribute to the union, regardless of the parameter settings.
Hopes that will help.
Sebastian, many thanks! This advice is very helpful.