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drying process

Hello user's COMSOL

I am trying to simulate a simple drying process with COMSOL , but I have been unable to link heat and mass transfer processes together.

With the program, I want to model a porous material that contains certain amount of moisture and how moisture moves over time.

I tried to combine "heat transfer through porous medium" and "species transport in porous media" physics modules together but so far it is not successful.

Is there a function or module or tool that I can apply to simulate a simple drying process?

Thanks for your valuable time and looking forward for the reply!!!

Sincerely,

2 Replies Last Post Jun 23, 2016, 11:54 AM EDT
Suresh Seetharam
Posted: 4 years ago Jun 19, 2013, 11:43 AM EDT
Hi,


Try to link the heat transfer module with Richard's equation in subsurface module because for moisture transfer you need suction-degree of saturation relationship. Of course, you need to introduce cross-coupling terms in both heat transfer and moisture transfer equations. In the moisture transfer especially it is very important to have vapour fluxes. In the heat transfer equation you need to have latent heat of vapourisation and convective components (if flow gradient is high). These cross couplings should be included within the source terms of the respective equations. In essence, you cannot simply couple the above equations in their bare form, unless COMSOL has introduced such ready made features, which I don't know.

From a COMSOL user perspective, there are two sources that you can readily look into and see if you get what you want.

1. Model exchange - Heat, Air and Moisture Transport - part 1/2 (2D) and part 2/2 A.W.M. (Jos) van Schijndel, Eindhoven University of Technology

2. A number of COMSOL papers - e.g.
www.comsol.com/search/?s=thm&subset=papers_presentations

Hope this helps.


Suresh
Hi, Try to link the heat transfer module with Richard's equation in subsurface module because for moisture transfer you need suction-degree of saturation relationship. Of course, you need to introduce cross-coupling terms in both heat transfer and moisture transfer equations. In the moisture transfer especially it is very important to have vapour fluxes. In the heat transfer equation you need to have latent heat of vapourisation and convective components (if flow gradient is high). These cross couplings should be included within the source terms of the respective equations. In essence, you cannot simply couple the above equations in their bare form, unless COMSOL has introduced such ready made features, which I don't know. From a COMSOL user perspective, there are two sources that you can readily look into and see if you get what you want. 1. Model exchange - Heat, Air and Moisture Transport - part 1/2 (2D) and part 2/2 A.W.M. (Jos) van Schijndel, Eindhoven University of Technology 2. A number of COMSOL papers - e.g. http://www.comsol.com/search/?s=thm&subset=papers_presentations Hope this helps. Suresh

Posted: 1 year ago Jun 23, 2016, 11:54 AM EDT
Hello, now I'm traying to simulate the drying of a pear in rectangular shape. I want to use : Transport of Diluted Species and heat transfer in solid.
Have you done your simulation? Maybe we can share informations?
Hello, now I'm traying to simulate the drying of a pear in rectangular shape. I want to use : Transport of Diluted Species and heat transfer in solid. Have you done your simulation? Maybe we can share informations?

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