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twice the true magnitude of the volume calculated in this axissymmetric 2D" approach with the Gauss formula

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If I calculate a volume with COMSOL in an "axissymmetric 2D" approach I can use two different ways:

Both utilize the way:
Definitions/Component Couplings/intgegration

1) I can directly choose a "domain" - carefully observing the need to check the checkbox "Compute integral in revolved geometry"

2) I can choose all boundaries and use the Gauss formula "SurfaceIntegral(r*solid.nr)" as the target.

The surprising fact is, that way #2 with the Gauss formula computes twice the true volume in this axissymmetric 2D" approach while it calculates correctly in the same way in the 3D approach.

I attach a mph file showing this behaviour.
Why is a result calculated which amounts the double magnitude of the correct result?


0 Replies Last Post 5 mar 2014, 11:14 GMT-5
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Hello Hans Gennerich

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