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changement d'unité - To switch the unit-system
Posted 16 ott 2010, 16:58 GMT-4 1 Reply
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Bonjour à tous,
J'ai crée, il y quelques temps, un modèle avec COMSOL en commençant par dessiner un cube de dimension nanométrique. La taille de ce cube est de 100 nm. Dans COMSOL, j'ai utilisé le mètre comme unité de longueur et de ce fait, j'ai entré 10^-7 [m] comme dimension de mon cube dans l'interface graphique.
Je souhaiterais maintenant convertir mon unité de longueur en nm (et donc passer des m aux nm sans toucher à la géométrie), de sorte que les dimensions de mon cube dans ce nouveau système d'unité soient de 100 [nm].
Comment puis-je changer le système d'unité utilisé afin de passer des mètres aux nanomètres et que ce changement affecte bien ma géométrie ?
La documentation de COMSOL n'aborde malheureusement pas ce problème de changement d'unité après-coup.
Je vous remercie pour votre aide
Antoine
**********************************************************
Hello everybody,
I created, there is some time, a model with COMSOL by starting to draw a small cube with nanometric size. The size of the cube close to 100 nm. In COMSOL, I used the meter for the lenght-unit and thus, I wrote 10^-7 [m] for the dimension of my cube in the graphic interface.
Now I would like to change the unit system used in order to switch from meter (m) to nanometer (nm) (and thus to write just 100 [nm] for the size of the cube). What is the process to do it ? Really I did not understand the COMSOL book !
Thank you for your help
Antoine
J'ai crée, il y quelques temps, un modèle avec COMSOL en commençant par dessiner un cube de dimension nanométrique. La taille de ce cube est de 100 nm. Dans COMSOL, j'ai utilisé le mètre comme unité de longueur et de ce fait, j'ai entré 10^-7 [m] comme dimension de mon cube dans l'interface graphique.
Je souhaiterais maintenant convertir mon unité de longueur en nm (et donc passer des m aux nm sans toucher à la géométrie), de sorte que les dimensions de mon cube dans ce nouveau système d'unité soient de 100 [nm].
Comment puis-je changer le système d'unité utilisé afin de passer des mètres aux nanomètres et que ce changement affecte bien ma géométrie ?
La documentation de COMSOL n'aborde malheureusement pas ce problème de changement d'unité après-coup.
Je vous remercie pour votre aide
Antoine
**********************************************************
Hello everybody,
I created, there is some time, a model with COMSOL by starting to draw a small cube with nanometric size. The size of the cube close to 100 nm. In COMSOL, I used the meter for the lenght-unit and thus, I wrote 10^-7 [m] for the dimension of my cube in the graphic interface.
Now I would like to change the unit system used in order to switch from meter (m) to nanometer (nm) (and thus to write just 100 [nm] for the size of the cube). What is the process to do it ? Really I did not understand the COMSOL book !
Thank you for your help
Antoine
1 Reply Last Post 17 ott 2010, 04:36 GMT-4
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Posted:
1 decade ago
Hi
I'll stick to English, if you are in V3.5 I beleive you are stuck, I would say stay in [m], correct the relative tolerance value.
But if you are in 4 you can change the default geometry unit (calculations remain in SI). You must just sort out if you should or not check the "Scale values when changing units" box.
As this one operates in a different logic than mine, I always test it out on a simple case make a new model, with a block and change the units once with and once without this tick box checked, and then carefully measure the final dimensions of the geoemtry (applies to existing geometry made before you change the geometry units.
(I believe if you have made your block with [m] units by deault and in1E-7[m] size you SHOULD CHECK the box, pls verify carefully)
The main issue about geometry units change is the relative repair tolerance for "small features".
If you make [nm] structures in the default [m] scale system and leave the 1E-6 relative tolerance these might get "erased out" during the "finish" (geomanalyse) operation.
--
Bonne chance
Ivar
I'll stick to English, if you are in V3.5 I beleive you are stuck, I would say stay in [m], correct the relative tolerance value.
But if you are in 4 you can change the default geometry unit (calculations remain in SI). You must just sort out if you should or not check the "Scale values when changing units" box.
As this one operates in a different logic than mine, I always test it out on a simple case make a new model, with a block and change the units once with and once without this tick box checked, and then carefully measure the final dimensions of the geoemtry (applies to existing geometry made before you change the geometry units.
(I believe if you have made your block with [m] units by deault and in1E-7[m] size you SHOULD CHECK the box, pls verify carefully)
The main issue about geometry units change is the relative repair tolerance for "small features".
If you make [nm] structures in the default [m] scale system and leave the 1E-6 relative tolerance these might get "erased out" during the "finish" (geomanalyse) operation.
--
Bonne chance
Ivar