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Determination of computed value at arbitrary point

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Hi,
I started working with COMSOL a few days ago, so I'm still a newbie.
What do I have to do in order to get the value of e.g. the magnetic-flux-density-norm at a specific point in my geometrie?

I have some ideas but don't know how to implement them:

1. Defining a point by coordinates and make COMSOL interpolate the value I'm interested in with the values at the adjecent nodes (this would be based on the interpolation-approach for the particular variable; should be no big deal for COMSOL). This would be a possibility for post-processing

2. If I know before the calculation that I'm interested in a value at a specific point, I could define it before mesing. Thus the defined point would be a node of the mesh and I could determine the value as node-value. But were can I find values at nodes? (In Ansys there is the possibility to see all node-values listed either by node-number or by coordinates of the node. Is there a similar possibility in COMSOL?)

Are these sensible basic ideas or are there different solutions in COMSOL?

Thx for now,
Daniel

1 Reply Last Post 2 sept. 2011, 15:33 UTC−4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 2 sept. 2011, 15:33 UTC−4
Hi

one thing to lear is that COMSOl is not working by "nodes" and "mesh elements", these are the last operation you do, and all physics are defined on the domains and boundaries. This is different from other "older" FEM programmes. Just as COMSOl has shape functions to define "higher order" mesh elements that you find in the older FEm programmes, this gives more freedom, and also more precision, and is separating better the pysics to the FEM mathematics, so they are not limiting your creativity

Once solved you can (in V4) define a point/line/plane ... onto which COMSOl will interpolate your values, and then you can plot the line, surface or the value(s) of a point (right click a Data set node).

But as you said you miht well define a point , and edge or a boundary in the CAD and then use that directly for your plot or value integration/average or any other calculation

--
Good luck
Ivar
Hi one thing to lear is that COMSOl is not working by "nodes" and "mesh elements", these are the last operation you do, and all physics are defined on the domains and boundaries. This is different from other "older" FEM programmes. Just as COMSOl has shape functions to define "higher order" mesh elements that you find in the older FEm programmes, this gives more freedom, and also more precision, and is separating better the pysics to the FEM mathematics, so they are not limiting your creativity Once solved you can (in V4) define a point/line/plane ... onto which COMSOl will interpolate your values, and then you can plot the line, surface or the value(s) of a point (right click a Data set node). But as you said you miht well define a point , and edge or a boundary in the CAD and then use that directly for your plot or value integration/average or any other calculation -- Good luck Ivar

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