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ill conditioned preconditioner, fluid in porous media simulation

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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

1 Reply Last Post 17 feb 2017, 02:53 GMT-5

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Posted: 7 years ago 17 feb 2017, 02:53 GMT-5
Did you check your study option? Which solver is used? I think it is better to change Iterative to Direct.
Did you check your study option? Which solver is used? I think it is better to change Iterative to Direct.

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