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Recreating normE_es expression from 3.5 in 4.0
Posted May 24, 2010, 6:33 p.m. EDT 1 Reply
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Ok, I'm a bit fustrated with the changes from 3.5 to 4.0. Especially not being able to duplicate work in 4.0 I did in 3.5.
Anyway, the questions I have is for a stationary 2D electrostatics problem.
I am interested in the electric field in the void between electrodes. Basically I want to electric field to stay below 25 kV/mm. This was a 15 to 20 minute task in 3.5. now fighting with all the changes in 4.0, up to 2 hours and still can not generate the plot I need.
It seems the expression normE_es no longer exists in 4.0. There are expressions for Ex_es and Ey_es, but I am not clear on how to use them to create the normE_es variable.
By the way the normE variable is defined as normE - electric field, norm - squareroot of the Electric field squared.
so does this mean I have to define an expression normE = (Ex_es^2+Ey_es^2)^0.5?
is it that simple?
Oh, and as a secondary question, how do I plot the results as kV/mm? It is not in the pull down options and it seems you can no longer enter units for plot displays.
Anyway, the questions I have is for a stationary 2D electrostatics problem.
I am interested in the electric field in the void between electrodes. Basically I want to electric field to stay below 25 kV/mm. This was a 15 to 20 minute task in 3.5. now fighting with all the changes in 4.0, up to 2 hours and still can not generate the plot I need.
It seems the expression normE_es no longer exists in 4.0. There are expressions for Ex_es and Ey_es, but I am not clear on how to use them to create the normE_es variable.
By the way the normE variable is defined as normE - electric field, norm - squareroot of the Electric field squared.
so does this mean I have to define an expression normE = (Ex_es^2+Ey_es^2)^0.5?
is it that simple?
Oh, and as a secondary question, how do I plot the results as kV/mm? It is not in the pull down options and it seems you can no longer enter units for plot displays.
1 Reply Last Post May 27, 2010, 1:35 a.m. EDT
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Posted:
1 decade ago
Hi
Just a question: Why not remain with 3.5a for some time ?
For all software you should no use a X.0 version for important work, its for learning (I agree I would prefer not to have to say this, but I have burned my finger so many times on so many software over the decades I have been using them that I'm resigned ;), and with v4.0 you have a new COMSOL with a new approach, it is worth to listen a couple of times to the presentations too to learn the iedeas behind.
Then check regularly the equations to understand how COMSOL defines and calculates the different variables, a norm remain a norm even in COMSOL, in V4 the names are new and must be learned again, but there are so many improved thing in V4 that I'm sure that within a years time you would not want to go back.
Have fun Comsoling
Ivar
Just a question: Why not remain with 3.5a for some time ?
For all software you should no use a X.0 version for important work, its for learning (I agree I would prefer not to have to say this, but I have burned my finger so many times on so many software over the decades I have been using them that I'm resigned ;), and with v4.0 you have a new COMSOL with a new approach, it is worth to listen a couple of times to the presentations too to learn the iedeas behind.
Then check regularly the equations to understand how COMSOL defines and calculates the different variables, a norm remain a norm even in COMSOL, in V4 the names are new and must be learned again, but there are so many improved thing in V4 that I'm sure that within a years time you would not want to go back.
Have fun Comsoling
Ivar