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Importing CT image on 5.2 version

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Dear all,

As a new user of COMSOL, I would like to inquire if there are any examples or instructions available for importing CT micro 2D images of a rock into COMSOL. Specifically, I am interested in creating a mesh and modeling diffusion in order to obtain the effective diffusion coefficient. I would greatly appreciate any guidance or resources you can provide on this matter.

Kind regards


3 Replies Last Post Jun 8, 2023, 3:07 p.m. EDT
Jeff Hiller COMSOL Employee

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Posted: 12 months ago May 26, 2023, 8:55 a.m. EDT
Updated: 12 months ago May 26, 2023, 9:59 a.m. EDT

Hello Abdelrazik,

This tutorial illustrates two different approaches you can take. The following blog posts may be useful to you as well: Modeling irregular shapes..., How to use interpolated material data... and Generating a simulation mesh.... Yet another approach consists in using a third party tool to generate the mesh and importing that mesh into COMSOL.

Best,

Jeff

PS: 5.2 is a rather old version of COMSOL, and there have been a number of enhancements made to the software since then, so not I am not sure that all techniques presented in these resources are available to you.

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Jeff Hiller
Hello Abdelrazik, [This tutorial](https://www.comsol.com/model/pore-scale-flow-488) illustrates two different approaches you can take. The following blog posts may be useful to you as well: [Modeling irregular shapes...](https://www.comsol.com/blogs/modeling-irregular-shapes-how-to-import-curve-data-and-loft-a-solid/), [How to use interpolated material data...](https://www.comsol.com/blogs/how-to-use-interpolated-material-data-to-model-irregular-geometries/) and [Generating a simulation mesh...](https://www.comsol.com/blogs/generating-a-simulation-mesh-of-a-femur-from-3d-data/). Yet another approach consists in using a third party tool to generate the mesh and importing that mesh into COMSOL. Best, Jeff PS: 5.2 is a rather old version of COMSOL, and there have been a number of enhancements made to the software since then, so not I am not sure that all techniques presented in these resources are available to you.

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Posted: 12 months ago Jun 8, 2023, 1:41 p.m. EDT

Dear Jeff,

I would like to understand how the .dxf file was created in COMSOL's pore scale example using an SEM image. I'm currently attempting to convert a specific .png image into a model where I can simulate diffusion in the black (porous) and white (non-porous) regions. However, I've encountered a problem during the conversion process. When I import the .dxf file into COMSOL, it appears that not all of the white regions are being detected accurately. Consequently, the flow is occurring in a larger area than intended. I would greatly appreciate any suggestions or advice you may have to help address this issue.

Furthermore, I've encountered situations where, upon importing a geometry, there is no boundary available to assign the concentration in COMSOL. I attempted to address this issue by constructing a rectangle over the image, but this approach resulted in considering both the porous and non-porous media as a single area for flow. As a consequence, I'm currently seeking alternative methods or suggestions to properly assign concentration boundaries in these cases.

I also have another question regarding resizing the geometry that has been built automatically by importing the .dxf file into Comsol. I found that after importing that the geometry is much bigger than the actual image size. Thank you so much for your cooperation.

Kind regards, Abdelrazik Elfar

Dear Jeff, I would like to understand how the .dxf file was created in COMSOL's pore scale example using an SEM image. I'm currently attempting to convert a specific .png image into a model where I can simulate diffusion in the black (porous) and white (non-porous) regions. However, I've encountered a problem during the conversion process. When I import the .dxf file into COMSOL, it appears that not all of the white regions are being detected accurately. Consequently, the flow is occurring in a larger area than intended. I would greatly appreciate any suggestions or advice you may have to help address this issue. Furthermore, I've encountered situations where, upon importing a geometry, there is no boundary available to assign the concentration in COMSOL. I attempted to address this issue by constructing a rectangle over the image, but this approach resulted in considering both the porous and non-porous media as a single area for flow. As a consequence, I'm currently seeking alternative methods or suggestions to properly assign concentration boundaries in these cases. I also have another question regarding resizing the geometry that has been built automatically by importing the .dxf file into Comsol. I found that after importing that the geometry is much bigger than the actual image size. Thank you so much for your cooperation. Kind regards, Abdelrazik Elfar

Jeff Hiller COMSOL Employee

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Posted: 12 months ago Jun 8, 2023, 3:07 p.m. EDT

The dxf file used in the pore scale example was authored by a third party, named in the pdf. I would recommend you contact them.

Best,

Jeff

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Jeff Hiller
The dxf file used in the pore scale example was authored by a third party, named in the pdf. I would recommend you contact them. Best, Jeff

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