Tutorial 6: Modeling Porous Medium in Comsol Multiphysics

[@garshaspkeyvan5546]

You are a life saver , I'm wishing for a day when my lexicon skills gets capable of putting my gratitude in words for this video, and you sire, its creator.

[@Teacheetah]

thanks for the comment,glad it helped you. #comsol

[@deshrajmeena7968]

very nicely explained, simply thanks for sharing this wonderful demonstration

[@Teacheetah]

thanks for your comment, glad you liked our COMSOL tutorial

[@basithv]

I tried using a porous SEM image obtained from google and prepared dxf image as said. But while importing to Comsol showing error. "The file contains no geometry objects of the requested type". Can u please help me to solve this issue

[@nafeeztanveenchowdhury359]

hi, have you got any videos where I can do electroosmosis of sludge between two circular electrodes?

[@annoon-i1l]

all tanks to that video, how can we model pseudo capacitor?

[@abhinav139]

Is it possible to simulate the porous resistive sensor as similar to one of your tutorials of micro pattern resistive sensor by using this method of using SEM image of porous conductive foam ?

[@Teacheetah]

By combining the procedures explained for the micro-patterned model and porous model in our tutorials, there might be a chance to model the piezo-resistive conductive foam system. It might be a bit tricky when the contact pairs need to be defined for the internal porous structure when building the model from an actual image. A more simplified way is to consider the pores as equal shapes (e.g. spheres) uniformly distributed through the structure.

[@abhinav139]

@@Teacheetah thank you , I am trying to simulate the 3D micro patterned based piezoresistive based sensor on the basis of your tutorial on 2D types

[@abhinav139]

@@Teacheetah it’s very informative video , it’s a request to continue such tutorials

[@abdelrazikelfar7643]

Great work. I have two questions about how to build the rectangle on the image and keep the shapes acting as a barrier for diffusion. Another question please, How to add the porosity and the adsorption to the porous media.

[@josephbainamndi1259]

Very nice demonstration

[@Teacheetah]

Thanks for the comment. Glad to hear that

[@josephbainamndi1259]

@@Teacheetah How to contact you and work on something?

[@Teacheetah]

Email us by [e-mail]

[@pandohaman1]

Sir, thank you for this video, i wanted to ask if this technique is possible for a 3D geometry, i am trying to model a sintered porous plate (cylindrical) thank you.

[@rincess9499]

Really helpful for new hands in porous media!But please tell me if you could recommend some pdf tutorials or videos for importing a 3D porous media model in COMSOL?I have tried with imageJ 3D viewer as a STL file, when I imported it into COMSOL I get a bothering error"Surfaces cannot be parameterized !!"

[@Teacheetah]

Thanks for the comment. We suggest you review the article and sources available in this reference: www.comsol.com/model/analyzing-porous-structures-on-the-microscopic-scale-85371

[@rincess9499]

@@Teacheetah Thanks for sharing.I will check it!

[@Teacheetah]

thanks for the support

[@Itseasy18]

Very useful. I have a doubt. when you formed the union the entire structure was a single entity but when you added the air material how is it possible that solid and the air part was partitioned.

[@AydaBouaziz-lj8wp]

Great work I just want to ask what is the name of the software of making binary version of an image !

[@jaa70]

is it possible to simulate electrolytes in liquid solutions? deposition? ion migration?

[@Teacheetah]

These problems can be modelled by COMSOL and we suggest to review the user’s guides available for Electrochemistry Module and Electrodeposition Module of COMSOL

[@Itseasy18]

Sir i want to create a porous material (porous Al2O3 ). Is their any provision in comsol to that. Are the porous material available in material library.

[@sampadlaha8818]

Thank you for the awesome video. I have a question. If I want to simulate fluid flow in a similar porous model as shown here, I need to make the fluid flow through the empty spaces, ie. the pores. But how to do that as the pores are not connected with one another? Could you please help?

[@Teacheetah]

Thanks for the comment and great question. We have simplified this model to a closed-cell foam which in fact the pores are not connected. Depending on the image from the porous media, you may process the image such that the pores are connected with an open-cell configuration. For example, if for this case we assign the solid domain with air and the air domain with solid (switch the air and solid domains), we can create a geometry with connected pores. Please let us know if you have any question

[@sampadlaha8818]

@@Teacheetah Thanks a lot for the suggestion! In this case, my doubt is if for the same geometry, I assign the connected domain ( actually the solid) as air or water and the discrete domain ( which is actually the pore spaces) as solid fibres, that would change the entire physics of the problem. In that case, if I try an experimental validation, it may not give a good match. Please convey your opinion regarding this. Also, are there any mail IDs where I can write to you?

[@Teacheetah]

Thanks for the comment and question. Again it depends on the image of the porous domain that we process and how the pores are connected in the image. We just mentioned switching domains to give the idea how an open-cell configuration can look like from an image not practically for this physics. We prefer to have all questions in here as others might have the same questions as you, and it will help them to solve their problems. If you want to send us a file regarding your question, please let us know. Thank you

[@tonoyk.mondal7106]

Hi, when i used the same path to build geometry in comsol from nanofiber surface SEM images I found some noise in the background. Do you have any suggestions on how to remove such noise?

[@marcoaurelio8097]

Congratulations on the playlist! Could you make a tutorial with planetary gears and how to calculate the contact force between gears? Could you also make a tutorial of two magnets being attracted to each other due to magnetic force? Could you make a tutorial of a magnet aligning itself with the external magnetic field due to magnetic torque? Thank you very much!

[@Teacheetah]

Thanks for sure, we will consider these topics for our future videos

[@muhammadhanifbinbaharuddin4071]

Nice demonstration. May i know is it posible to construct a solid pole with porous structure?

[@Teacheetah]

Thanks for the comment. Would you please give us a bit more info about solid pole and what you exactly mean by that so that we might be able to help more?

[@muhammadhanifbinbaharuddin4071]

@@Teacheetah I want to create 3d pole model but inner structure is not full solid but porous like bone

[@Teacheetah]

Thanks for the comment. We will get back to you ASAP.

[@Teacheetah]

Similar to what shown in this video, you may use the 3D image of your domain instead (e.g. CT-image) and convert to a mesh, and perform the study. The following article might be useful: www.synopsys.com/simpleware/resources/case-studies/pore-scale-chemical-transport.html

[@rgtalks2104]

Is it possible to simulate multicomponent and multiphase mixture and study the rheological properties of the resultant mud/fluid

[@vikashkumar-cr7ee]

I want to simulate a transient three-phase flow in porous media considering capillary action (Filter paper soaking water up). The porous zone is initially filled with air. I want to model the displacement of air with two liquids (water and glycerin, let's say) due to capillary forces. My main interest is the degree of wetting and the spreading of the wetting front. How to model capillary effects in the porous zone? I did the simulation but It is throwing an error " Unknown function or operator, Name: step1" Can anyone help me out?

[@Teacheetah]

Hi Vinash, thanks for the comment and question, your problem is very specific, however, we have found a few resources that might help you. Please check links below: www.comsol.com/blogs/computing-porosity-and-permeability-in-porous-media-with-a-submodel/ www.comsol.com/blogs/simulate-three-phase-flow-with-a-new-phase-field-interface/ www.comsol.com/porous-media-flow-module We will look for further resources, and will update you. Stay tuned

[@TaherHafiz]

Team can someone help to get the contact information of the presenter I have a technical question for him or for any one has experience in COMSOL

[@fantomfantom4675]

The explanation was very fluent. Thanks #teacheetah

[@Teacheetah]

You are welcome!

[@tonoyk.mondal7106]

Hey, very nice work! But I am facing some issues. I am building nanofiber surface geometry from an SEM image. I have found some background solid which is unexpected. In other words, it is not importing as a pure contrast or binary! instead, some background is taken with its fiber samples. Do you have suggestions for that? Thank you!

[@heenasammi8919]

Hello Sir, Your vedio is very helpful. In this vedio you have solved the capacitance related problem. Can you please suggest us some points if we want to solve optics-related problems (like if we are exciting our sample (SEM image) with one particular wavelength than what kind of boundary conditions we need to apply). How we can get local electric field around the particles (output) and so on?

[@rgtalks2104]

got this error while emulating the same in my comsol: Undefined material property 'epsilonr' required by Charge Conservation 1

[@Teacheetah]

You may need to check if the properties of the materials assigned to the domains are fully defined. It seems that the relative permittivity value of a material is missing

[@rgtalks2104]

@@Teacheetah yes it's done. Thank you.

[@Itseasy18]

Can someone please send a SEM image for demo so that I can run this once. It will be a great help.

[@AlexandreTheFirst]

What if I don't have a SEM?

[@Teacheetah]

Thanks for the comment. The method proposed here is based on the image captured from a porous material using SEM, optical, scan, etc. Please note that porous materials may also be modelled in the software by other techniques and modules e.g. porous interface.

[@Itseasy18]

@@Teacheetah please elaborate on this

[@Itseasy18]

@@Teacheetah please elaborate if we want to vary porosity manually.