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Help with the model of capillary wicking in a porous material

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Hi,

I was trying to use the model provided on Comsol website to work on a time dependent wicking problem in a paper strip where the width is a not constant value (a 6cm-width rectangular wicking pad with a 1cm-width leg below).

Here's the link I found from comsol:

https://www.comsol.com/model/wicking-in-a-paper-strip-79061

I used the same boundary conditions as the above link and I think my mesh should be OK, but there's always an error after running for a while. For some unknown reason, the s value ( the effective saturation) of air (or maybe water) becomes negative.

Except for the geometry, all I changed were the parameters like properties of air and water. Anyone can give me any idea about which part goes wrong and why s becomes negative?

Any help is appreciated. Thanks a lot.

Jing


0 Replies Last Post 23 avr. 2020, 00:59 UTC−4
COMSOL Moderator

Hello Jing Yuan

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