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Thermal coupling in hydro-mechanical analysis for a saturated soil
Posted Aug 31, 2014, 12:42 p.m. EDT Porous Media Flow, Modeling Tools & Definitions, Parameters, Variables, & Functions 3 Replies
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Hi everybody,
I would have some very important questions for you.
I am modeling a saturated soil deposit with the poro-elasticity interface and I would like to couple thermal effects. For this reason, I am also using the heat transfer in porous media interface. However, I would like to ask you if:
1. The solely poroelastocity interface takes into account the thermal induced effects on the mechanical behavior of the soil matrix, i.e., does the tensorial formulation of this interface takes into account thermal induced stress? I have seen that the poroelasticity interface is a sub-module of the solid mechanics one (which can be coupled with thermal effects through the multiphysics interface, both referring to temperature -for the flow in the porous media- and the stress calculation), however, anything is specified about this coupling with this specific module (Ii.e., the multiphysics interface is no more applicable to link the heat transfer and poroelasticity interfaces). May I use all the aforementioned three modules?
2. I have seen that the mass conservation formulation of the poroelasticity interface does not consider the term which expresses the time derivative of temperature multiplied by the relation which expresses the volume filled by water and solid phase through the porosity of the considered soil matrix. Do you know how could I implement this formulation?
Many thanks for your help in this matter,
Alessandro
I would have some very important questions for you.
I am modeling a saturated soil deposit with the poro-elasticity interface and I would like to couple thermal effects. For this reason, I am also using the heat transfer in porous media interface. However, I would like to ask you if:
1. The solely poroelastocity interface takes into account the thermal induced effects on the mechanical behavior of the soil matrix, i.e., does the tensorial formulation of this interface takes into account thermal induced stress? I have seen that the poroelasticity interface is a sub-module of the solid mechanics one (which can be coupled with thermal effects through the multiphysics interface, both referring to temperature -for the flow in the porous media- and the stress calculation), however, anything is specified about this coupling with this specific module (Ii.e., the multiphysics interface is no more applicable to link the heat transfer and poroelasticity interfaces). May I use all the aforementioned three modules?
2. I have seen that the mass conservation formulation of the poroelasticity interface does not consider the term which expresses the time derivative of temperature multiplied by the relation which expresses the volume filled by water and solid phase through the porosity of the considered soil matrix. Do you know how could I implement this formulation?
Many thanks for your help in this matter,
Alessandro
3 Replies Last Post Sep 2, 2014, 11:38 a.m. EDT
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Posted:
1 decade ago
Hi,
If you have structural mechanics module then I think you will automatically get the thermal expansion provision in the poroelasticity. If not, you may have to add that extra term yourself, but please double check if COMSOL has updated the model since then. Long time ago, I had discussed this in the following thread www.comsol.com/community/forums/general/thread/41618. See if this works.
If you do not have thermal term in the mass conservation, you then need to add that into the source term explicitly. That is, you go to Poroelasticity>domain>Darcy's law>mass source.
Suresh
If you have structural mechanics module then I think you will automatically get the thermal expansion provision in the poroelasticity. If not, you may have to add that extra term yourself, but please double check if COMSOL has updated the model since then. Long time ago, I had discussed this in the following thread www.comsol.com/community/forums/general/thread/41618. See if this works.
If you do not have thermal term in the mass conservation, you then need to add that into the source term explicitly. That is, you go to Poroelasticity>domain>Darcy's law>mass source.
Suresh
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Posted:
1 decade ago
Hello,
thank you very much for your response.
I would still ask you a question, which regards the initialization of my poroelastic problem. I have defined all the properties of my material (solid matrix and water). If I run Comsol for getting the initial values all is ok. However, if I run a time dependent calculation without doing anything (which would involve any variation of the mechanical behaviour of my system), I notice that my problem is in practice not in equilibrium. In fact, I have a redistribution of pore water pressure that at the top of my deposit is no more zero (i.e., not following the hydrostatic trend defined by gamma_w*z) and a consequent redistribution of stress.
Could you help me in such matter?
Thank you a lot,
Alessandro
thank you very much for your response.
I would still ask you a question, which regards the initialization of my poroelastic problem. I have defined all the properties of my material (solid matrix and water). If I run Comsol for getting the initial values all is ok. However, if I run a time dependent calculation without doing anything (which would involve any variation of the mechanical behaviour of my system), I notice that my problem is in practice not in equilibrium. In fact, I have a redistribution of pore water pressure that at the top of my deposit is no more zero (i.e., not following the hydrostatic trend defined by gamma_w*z) and a consequent redistribution of stress.
Could you help me in such matter?
Thank you a lot,
Alessandro
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Posted:
1 decade ago
Hi,
Your problem has CAD module, which I don't have. Thus I do not know if the geometry I see is the correct one.
Suresh
Your problem has CAD module, which I don't have. Thus I do not know if the geometry I see is the correct one.
Suresh