[snappyHexMesh] defining porous zone in toposet

mvee · January 31, 2017, 02:02

Dear all

I am new to snappy and openfoam. I want to simulate flow through the porous zone. I am using snappy (attachment) to create a mesh. I have defined porouzzone1 STL file which is my porous zone. I want to see it in ParaView. When I observed the boundary in polyMesh, I did not find any patches related to porouszone1. I thought I need toposet to pass. I saw toposet to be used for regular geometries. How can I use it for user-defined geometries (as in my STL file)? Please note that Another stl file - fluid.stl is the solid obstruction which is removed by considering location in mesh point.

Thank you
Mahesh

mo_na · January 31, 2017, 14:12

Hey Mahesh,

I am not quite sure what you are trying to simulate but maybe ihFoam could be a good solver for you? Its based on interFoam and includes the flow through porous material. Its quite easy to define porous zones with it.
Also you defined your porous zone as patch type "wall". Is it supposed to be a boundary and not an actual zone? I am a little confused...

Cheers,
Mona

mvee · January 31, 2017, 22:04

Hi Mona

Thanks for your reply.

We specify bounding box with dimension in toposetdict to patch the specific zone as porous. Now here, in this case, I want to specify irregular shape (as in STL file) instead bounding box with dimension. I can see cellZones in constant/polyMesh directory which consists of my porous zone.

My question is how can I treat irregular shape (i.e STL file) or porous zone of cellZones in topoSetDict?

Am I clear?

Thank you
Mvee

mo_na · February 1, 2017, 06:21

okay I think I got it! I have never done that before but maybe one of these threads can help you:

https://www.cfd-online.com/Forums/op...s-toposet.html

Open Foam /Setfields

mvee · February 1, 2017, 23:40

Hi Mona

I solved the problem. I used zoneToCell. I am surprised that Do I really need to convert zone to cell in order to treat porosity?

Thanks for your reply

Regards
Mvee

JoshuaB-L · July 13, 2020, 13:28

Hi Mvee,

Could you elaborate on how you used the zoneToCell? It would be great to see examples of your dict files and the STL file you used.

I would like to define a porous zone using a source term defined in fvOptions. I would like to apply the porous zone to the cells inside of the STL mesh very similar to what you did I think.

I am trying to calculate wind flow through a tree canopy and tree canopy being defined as a porous zone.

Would you be willing to share your example case?

Look forward to your reply.

Regards

Joshua

February 1, 2017, 23:40	solved	#5
mvee Senior Member Vaze Join Date: Jun 2009 Posts: 172 Rep Power: 17	Hi Mona I solved the problem. I used zoneToCell. I am surprised that Do I really need to convert zone to cell in order to treat porosity? Thanks for your reply Regards Mvee JoshuaB-L likes this.

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January 31, 2017, 14:12		#2
mo_na Member Mona Join Date: Mar 2016 Location: Berlin Posts: 49 Rep Power: 10	Hey Mahesh, I am not quite sure what you are trying to simulate but maybe ihFoam could be a good solver for you? Its based on interFoam and includes the flow through porous material. Its quite easy to define porous zones with it. Also you defined your porous zone as patch type "wall". Is it supposed to be a boundary and not an actual zone? I am a little confused... Cheers, Mona

January 31, 2017, 22:04		#3
mvee Senior Member Vaze Join Date: Jun 2009 Posts: 172 Rep Power: 17	Hi Mona Thanks for your reply. We specify bounding box with dimension in toposetdict to patch the specific zone as porous. Now here, in this case, I want to specify irregular shape (as in STL file) instead bounding box with dimension. I can see cellZones in constant/polyMesh directory which consists of my porous zone. My question is how can I treat irregular shape (i.e STL file) or porous zone of cellZones in topoSetDict? Am I clear? Thank you Mvee

February 1, 2017, 06:21		#4
mo_na Member Mona Join Date: Mar 2016 Location: Berlin Posts: 49 Rep Power: 10	okay I think I got it! I have never done that before but maybe one of these threads can help you: https://www.cfd-online.com/Forums/op...s-toposet.html Open Foam /Setfields

July 13, 2020, 13:28		#6
JoshuaB-L New Member Joshua Join Date: Mar 2019 Location: Berlin Posts: 2 Rep Power: 0	Hi Mvee, Could you elaborate on how you used the zoneToCell? It would be great to see examples of your dict files and the STL file you used. I would like to define a porous zone using a source term defined in fvOptions. I would like to apply the porous zone to the cells inside of the STL mesh very similar to what you did I think. I am trying to calculate wind flow through a tree canopy and tree canopy being defined as a porous zone. Would you be willing to share your example case? Look forward to your reply. Regards Joshua