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Coupled PDEs, Last time step is not converged
Posted 30 déc. 2013, 08:24 UTC−5 Heat Transfer & Phase Change, Studies & Solvers Version 4.3b 1 Reply
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I am new to COMSOL, and what I encountered is about coupled PDEs. I have two coupled PDEs in one physics model in general form. One is about heat transfer (T), the other is an ODE used for the source term of the heat transfer (T). The ODE looks like du/dt=f(u,T), namely du/dt is a function of u and T.
When I ignore the T, like du/dt=f(u), COMSOL works. But it doesn't work when I consider the T. As follows.
Repeated error test failures. May have reached a singularity.
Time : 0.334945980028302
Last time step is not converged.
Thanks,
Du
Hello Du Mingyue
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i m confronting the same kind of problem
here i used u v to do the linear elastic mechanics
but when i need to caculate du/dt or dv/dt, the solver give me the error info: may have reached a singularity
TIME ：0
but if i caculate the ut or vt in postprocessing, they worked fine!
it is due to the terms i used in the PED, or it is due to configuration of the solver?