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Lagrange multiplier in axial symmetry
Posted 11 janv. 2017, 12:46 UTC−5 Heat Transfer & Phase Change, Geometry, Mesh Version 5.2 2 Replies
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i am modelling a moving boundary interface (Stefan Problem), using the Lagrange multiplier T_lm from heat transfer analysis for prescribed normal mesh velocity in the deformed geometry physics.
The model is almost identical to the 2D Tin melting front example from Comsol library:
www.comsol.com/model/tin-melting-front-6234
except that I work in axial symmetry and my interface is perpendicular to the axis of symmetry.
When I solve, the Lagrange multiplier T_lm is always zero at r=0. I guess I am missing something fundamental here ? Does anyone have a hint for me ?
Thank you and Regards
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Flanell
Hello Flanell
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In fact, the Lagrange multiplier T_lm should be in W/m2, but for symetric problems is in W/m. you should easily just use: T_lm [W/m^2]/(rho_Si*DelH*r*pi) instead of T_lm [W/m^2]/(rho_Si*DelH). In this case the Lagrange multiplier transfer from "per radius" to "per area (Pi*r*r*)"
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thanks alot!
I figured it out alreday and it works like you said
Best
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Flanell