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Variable moisture source in COMSOL diffusion simulation
Posted 16 apr 2014, 22:26 GMT-4 Parameters, Variables, & Functions Version 4.4 1 Reply
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Hello,
I would like to model the moisture diffusion process in the cellulose paper by using "Transport of Diluted Species" module in COMSOL.
The paper board is 1 mm thick with diameter of 75 mm. One side of the paper is contacted with the humid air which can be regarded as the moisture source. The other side of the paper is concealed. So the moisture will diffuse from humid part to another side. If the temperature and moisture source (humidity of air) keeps as constant, that would be no problem. I can see the dynamic transportation of the moisture in the paper board at different time. The real case is that the moisture source is a periodic variable with time and I already got the its value during one period which is saved as excel file (.xls). I just wonder how can I load the time dependent moisture source into my COMSOL model and change the boundary condition (i.e. humidity of the air is set as boundary condition) as variable to simulate the dynamic moisture distribution in the paper board?
Thank you.
I would like to model the moisture diffusion process in the cellulose paper by using "Transport of Diluted Species" module in COMSOL.
The paper board is 1 mm thick with diameter of 75 mm. One side of the paper is contacted with the humid air which can be regarded as the moisture source. The other side of the paper is concealed. So the moisture will diffuse from humid part to another side. If the temperature and moisture source (humidity of air) keeps as constant, that would be no problem. I can see the dynamic transportation of the moisture in the paper board at different time. The real case is that the moisture source is a periodic variable with time and I already got the its value during one period which is saved as excel file (.xls). I just wonder how can I load the time dependent moisture source into my COMSOL model and change the boundary condition (i.e. humidity of the air is set as boundary condition) as variable to simulate the dynamic moisture distribution in the paper board?
Thank you.
1 Reply Last Post 17 apr 2014, 02:11 GMT-4
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Posted:
1 decade ago
I think that water is not diffusing in paper but capillary forces are sucking it very efficiently. Dip a piece of paper into water and you see how fast paper front is advancing, it is not diffusion.
I know this is not a reply to your question ;)
I know this is not a reply to your question ;)