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Failed to evaluate variable Jacobian problem in a stationary & time dependent problem
Posted Feb 18, 2011, 8:11 a.m. EST Low-Frequency Electromagnetics Version 4.1 2 Replies
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Hello,
I'm new to Comsol and I'm trying to solve a 2D problem in which electric potential calculation and diffusion are involved, in a rectangular domain in which a portion is defined, as intial condition, as an high concentration region (hence high conductivity).
My workflow is as follows: I solve the electrostatic problem with "Electric current" with a stationary solutor (stationary solver) first step of the solver. Then the solutor has a second time dependent step in which the diffusion equation is solved (I use pde module). The electric field is used as an input for the diffusion parameters.
Every time I try to solve I get:
Failed to evaluate variable Jacobian.
- Variable: ec.Ey
- Geometry: 1
- Domain: 1
I cannot understand why? The software is capable to solve the problem when the sencond step of the solver and the related physics are disabled and this probably means that the solver is able to compute the potential solution.
I'll thank you in advance for your help
Stefano
I'm new to Comsol and I'm trying to solve a 2D problem in which electric potential calculation and diffusion are involved, in a rectangular domain in which a portion is defined, as intial condition, as an high concentration region (hence high conductivity).
My workflow is as follows: I solve the electrostatic problem with "Electric current" with a stationary solutor (stationary solver) first step of the solver. Then the solutor has a second time dependent step in which the diffusion equation is solved (I use pde module). The electric field is used as an input for the diffusion parameters.
Every time I try to solve I get:
Failed to evaluate variable Jacobian.
- Variable: ec.Ey
- Geometry: 1
- Domain: 1
I cannot understand why? The software is capable to solve the problem when the sencond step of the solver and the related physics are disabled and this probably means that the solver is able to compute the potential solution.
I'll thank you in advance for your help
Stefano
2 Replies Last Post Feb 18, 2011, 9:35 a.m. EST
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Posted:
1 decade ago
Hi
you should recheck all the definitions used for Ey, or to create it, probably you have something mistyped in one of the BC's or the initial conditions
--
Good luck
Ivar
you should recheck all the definitions used for Ey, or to create it, probably you have something mistyped in one of the BC's or the initial conditions
--
Good luck
Ivar
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Posted:
1 decade ago
Thank you for your help Ivar, I'll check