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Help solving own set of PDE's

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My intention is to solve my own 1D system of equations using the 'General form PDE', which consists of four equations and unknowns: phi (melt fraction), u and v (velocity vectors) and dp (pressure difference). The issue is that this set of equations is valid for 0<phi<1. On the other hand, when phi=0 anywhere along the domain, a different simplified set PDE's must be solved.

Is it possible to solve such a problem using COMSOL? Perhaps defining under the model 1 node two different physics, defined by the two different set of equations: General form PDE 1 and General form PDE 2, and then somehow tell the solver: solve 'General form PDE 1' if 0<phi<1 else 'General form PDE 2'. Is this possible?

If not what are the alternatives?

Thanks in advance.

0 Replies Last Post Sep 26, 2012, 7:00 a.m. EDT
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Hello James Hickey

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