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ill conditioned preconditioner, fluid in porous media simulation
Posted 15 févr. 2017, 15:02 UTC−5 Fluid & Heat Version 5.2 1 Reply
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Hi everyone, I was trying to do a simulation of fluid in porous media.
The geometry I had was a channel, with both ends non-porous, and the middle part porous.
In the porous part, I was using the "Darcy's law" model.
In the non-porous parts, I used simply the "Laminar Flow" model.
Fluid properties were set as water. Matrix properties were: 0.94 porosity, 1.33e-13 permeability.
Inlet speed was 0.02 m/s. The initial values were: speed, 0.02 m/s; p was set as 101325 Pa but I don't know if that's appropriate.
Then I ran the computation. COMSOL tells me because of "ill conditioned preconditioner", my solutions don't converge.
Anyone know what could've been wrong, and what i should do to fix it?
Thanks so much
The geometry I had was a channel, with both ends non-porous, and the middle part porous.
In the porous part, I was using the "Darcy's law" model.
In the non-porous parts, I used simply the "Laminar Flow" model.
Fluid properties were set as water. Matrix properties were: 0.94 porosity, 1.33e-13 permeability.
Inlet speed was 0.02 m/s. The initial values were: speed, 0.02 m/s; p was set as 101325 Pa but I don't know if that's appropriate.
Then I ran the computation. COMSOL tells me because of "ill conditioned preconditioner", my solutions don't converge.
Anyone know what could've been wrong, and what i should do to fix it?
Thanks so much
1 Reply Last Post 17 févr. 2017, 02:53 UTC−5
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Posted:
8 years ago
Did you check your study option? Which solver is used? I think it is better to change Iterative to Direct.