Discussion Forum

Posted: 10 years ago 22 août 2014, 02:39 UTC−4

Hi, Have you worked out any approach to solve the problem? I've had the same problems, maybe we can communicate with one another. Many thanks, Hongyan

Posted: 10 years ago 25 août 2014, 11:36 UTC−4

Hi, I've worked on models of phase changes in porous media as well. If it is the case that you have a phase change occuring troughout the entire media and, hence, if you are dealing with two phase flow, then the problem is very difficult. You may contact me if you whish to work on such solution. In the cases where there is a front between the two phases, it is a bit more easy. In your case it seems that you can model two porous materials with a moving border in between. One of those materials has the phase1 and the other of the materials has the phase2. Then you can use the mass transfer ans heat transfer between those two layers to determine the rate of phase change and the rate at which the border moves. There are several models from which you can obtain inspiration on how to set up this model. In the Comsol libraries there is a case of a malting front in tin and of heating a patty. http://www.comsol.asia/model/tin-melting-front-6234 http://www.comsol.asia/model/convection-cooking-of-chicken-patties-448 articles that you may want to read are: Moisture transport in intensive microwave heating of biomaterial: a multiphase porous media model (Ni, Datta and Torrance 1999) Mathematical modeling of bread baking process (Yhang and Datta 2006) Porous media approaches to studying simultaneous heat and mass transfer in food processes. I & II (Datta 2007) Surface heat and mass transfer coefficients for multiphase porous media transport models with rapid evaporation (Halder and Datta 2012) Multiphase and multicomponent transport with phase change during meat cooking (Dhall, Halder Datta 2012) Multiphase Flow in Porous Media with Phase Change. Part II: Analytical Solutions and Experimental Verification for Constant Pressure Steam Injection (Bergins, Crone Strauss, 2005) Numerical modeling of coupled heat and water steam flow in spatially variable permeability of saturated porous media (Muhieddinne, Canot, March, 2010) Simulation of constant pressure steam injection in a porous medium (Soda, Wang, Cheng 1998) Besides dozens of articles on experiments and many others on modeling that I have missed or did not found important. Note that the latter article is on the modeling of steam in rock.

Posted: 10 years ago 11 nov. 2014, 22:10 UTC−5

Hi,I have worked on the first kind of model too. In my model, I designed the porous media to react into two phases-----solid &gas. Apart from that, the gas was expected to stay in the media for a while. However, I never made it. Could U help me with this problem? Thank U very much! [QUOTE] Hi, I've worked on models of phase changes in porous media as well. If it is the case that you have a phase change occuring troughout the entire media and, hence, if you are dealing with two phase flow, then the problem is very difficult. You may contact me if you whish to work on such solution. In the cases where there is a front between the two phases, it is a bit more easy. In your case it seems that you can model two porous materials with a moving border in between. One of those materials has the phase1 and the other of the materials has the phase2. Then you can use the mass transfer ans heat transfer between those two layers to determine the rate of phase change and the rate at which the border moves. There are several models from which you can obtain inspiration on how to set up this model. In the Comsol libraries there is a case of a malting front in tin and of heating a patty. http://www.comsol.asia/model/tin-melting-front-6234 http://www.comsol.asia/model/convection-cooking-of-chicken-patties-448 articles that you may want to read are: Moisture transport in intensive microwave heating of biomaterial: a multiphase porous media model (Ni, Datta and Torrance 1999) Mathematical modeling of bread baking process (Yhang and Datta 2006) Porous media approaches to studying simultaneous heat and mass transfer in food processes. I & II (Datta 2007) Surface heat and mass transfer coefficients for multiphase porous media transport models with rapid evaporation (Halder and Datta 2012) Multiphase and multicomponent transport with phase change during meat cooking (Dhall, Halder Datta 2012) Multiphase Flow in Porous Media with Phase Change. Part II: Analytical Solutions and Experimental Verification for Constant Pressure Steam Injection (Bergins, Crone Strauss, 2005) Numerical modeling of coupled heat and water steam flow in spatially variable permeability of saturated porous media (Muhieddinne, Canot, March, 2010) Simulation of constant pressure steam injection in a porous medium (Soda, Wang, Cheng 1998) Besides dozens of articles on experiments and many others on modeling that I have missed or did not found important. Note that the latter article is on the modeling of steam in rock. [/QUOTE]

Posted: 9 years ago 24 févr. 2015, 03:00 UTC−5

I am modelling biological material, where a porous substance is subjected to heating and consequently phase change. I have used 'Heat transfer in porous media' coupled with "Species transport" to simulate convection. However, I wish to include the phase change solid food material into oil and water. Can anyone share with me any of the insights since i am in desperate need to simulate a model as part of my degree project. Many thanks,