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DC discharge - Undefined value found in the stiffness matrix
Posted 02.02.2015, 04:12 GMT-5 Plasma Physics, Mesh, Studies & Solvers Version 4.4 2 Replies
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I’m trying to solve a time-dependent study on a DC discharge 2d model. I inserted some fictitious boundaries in the geometry in order to facilitate the creation of a mapped mesh, but when I try to compute the study the following error occurs:
Undefined value found.
- Detail: Undefined value found in the stiffness matrix.
There are 1000 equations giving NaN/Inf in the matrix rows for the variable comp1.En.
at coordinates: (0.00101,4.3275e-005), (0.00101,2.625e-005), (0.00103,4.3275e-005), (0.00103,2.625e-005), (0.00105,4.3275e-005), ...
and similarly for the degrees of freedom, NaN/Inf in the matrix columns.
I think that BC and meshing are well defined, in fact the model is successfully solved if the fictitious boundaries are not inserted in the geometry and a free triangular mesh is used. But I would prefer to use a mapped mesh. Can someone help me?
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When using the finite volume formulation, internal boundaries in the plasma region cause this error. The technique you mentioned is a good way to get around the problem.
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Luke Gritter
AltaSim Technologies