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Equation based modeling (General form PDE)

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Hi all

I've been trying to simulate the electro magnetic effect on fluid flow for a cube geometry with spherical hole inside. momentum equation works fine. I've written the continuity equation with periodic boundary conditions on all faces (in pairs). But when I try and run the program, I get an error message reading:

*" - Feature: Stationary Solver 1 (sol1/s1) Failed to find a solution. General Form PDE 2 Singular matrix.

There are 41446 void equations (empty rows in matrix) for the variable comp1.p1. at coordinates: (-0.475897,-0.43475,-0.5), (-0.449108,-0.473212,-0.475897), (-0.470065,-0.399854,-0.427757), (-0.476182,-0.4113,-0.36878), (-0.423205,-0.440337,-0.47384), ...

and similarly for the degrees of freedom (empty columns in matrix). In General Form PDE 2: Returned solution is not converged. Not all parameter steps returned. "

Does anyone know what causes this, and how I can avoid it? I couldn't find anything on the website.


0 Replies Last Post Nov 13, 2021, 1:44 a.m. EST
COMSOL Moderator

Hello Promasree Majumdar

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