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Plotting the gradient

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Hi everybody!
I'm still very new to Comsol so the answer of my question might be obvious for some of you but I just don't get it.

My question is:
How can I plot the gradient (of an electric potential) on a surface of a geometry. Later on, I'd like to get the gradient for all points of an contour plot. I actually only need the gradient for these points and not for all on the surface but I also would like to know how to do it for all points.

I know the variable ux, uy and uz etc give me the values the gradient at a specific point but I've no idea how I can use these variables inside a plot (or a result table?). I hope somebody can help me or give me a hint how to do something like this in general or will tell me where I can find the needed informations to find it out by myself.

Thank you very much!
Daniel

3 Replies Last Post 27.06.2011, 11:48 GMT-4
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Hello Daniel Wagner

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Posted: 1 decade ago 20.06.2011, 14:22 GMT-4
I've been trying to do the same thing. Have you figured it out?
I've been trying to do the same thing. Have you figured it out?

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Posted: 1 decade ago 21.06.2011, 20:39 GMT-4
The gradient of potential with respect to x and y are "Vx" and "Vy". COMSOL recognizes these variables as representing the spatial derivatives of the dependent variable, V. I think it works for any dependent variable. In heat transfer, for example, Tx and Ty, are spatial derivatives of temperature with respect to x and y.
The gradient of potential with respect to x and y are "Vx" and "Vy". COMSOL recognizes these variables as representing the spatial derivatives of the dependent variable, V. I think it works for any dependent variable. In heat transfer, for example, Tx and Ty, are spatial derivatives of temperature with respect to x and y.

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Posted: 1 decade ago 27.06.2011, 11:48 GMT-4
I'd like the gradient of the electric field. Comsol uses Ex, Ey, and Ez for the components of the E field. In that case, I don't think Ex would be the spatial derivative. The notation I've been using and seems to work is, d(Ex,x), if I want the gradient of the x component of the E field.
I'd like the gradient of the electric field. Comsol uses Ex, Ey, and Ez for the components of the E field. In that case, I don't think Ex would be the spatial derivative. The notation I've been using and seems to work is, d(Ex,x), if I want the gradient of the x component of the E field.

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