Sample region of a patch

JensD · June 29, 2018, 05:48

I am trying to extract temperatures from a patch (a cylindrical wall), however I'm only interested in the values between specific axial coordinates. Currently, I use sampleDict to extract all temperature data of the patch and remove all undesired values manually.

For other kinds of sampling you can specify a sampling region and I'm wondering if this option is available for patch sampling. Anyone have any suggestions?

RobertHB · June 29, 2018, 07:15

Hello Jens,

have you tried splitting your original patch into multiple smaller patches and just sampling the subregion you are interested in? E.g. creating a faceSet of the region of interest and then using createPatch to generate a patch from that faceSet?

JensD · June 29, 2018, 08:10

Hi Robert

Thanks for the response. This seems like a good method. On selecting the faces, I'm thinking of first selecting a faceSet with boxToFaces (box covering the region) and then make a subset of this with the pathToFace source to select only the faces that are on the wall patch.

Would you advise this or do you have another way of tackling this?

RobertHB · June 29, 2018, 08:28

Sounds like the way to go. The setSet utility has an action called subset that may be used for the operation of intersecting the two set.

Another way may be creating the box set, and the cylinder set. Then substracting the cylinder from the box, leaving you will only faces that are not part of the cyclinder. Upon inverting this latest cellSet you should end up with only the faces belonging to your cylinder.

JensD · June 29, 2018, 09:42

I managed to create the patch, but I can't sample or visualize as the size of the patch in my polyMesh is now different from the one in my time steps. Do I need to do something similar to the simulation results (T, p, U, ...) to allow sampling of this subregion?

RobertHB · June 29, 2018, 09:48

Oh sorry, i should have mentioned that. My approach has to be followed before you run your simulation, so you get results for the newly created patch.

JensD · June 29, 2018, 10:15

Quote:

Originally Posted by RobertHB

Oh sorry, i should have mentioned that. My approach has to be followed before you run your simulation, so you get results for the newly created patch.

Well ... that's unfortunate ...

June 29, 2018, 05:48	Sample region of a patch	#1
JensD New Member Join Date: Mar 2015 Posts: 12 Rep Power: 11	I am trying to extract temperatures from a patch (a cylindrical wall), however I'm only interested in the values between specific axial coordinates. Currently, I use sampleDict to extract all temperature data of the patch and remove all undesired values manually. For other kinds of sampling you can specify a sampling region and I'm wondering if this option is available for patch sampling. Anyone have any suggestions?

June 29, 2018, 07:15		#2
RobertHB Senior Member Robert Join Date: May 2015 Location: Bremen, GER Posts: 292 Rep Power: 12	Hello Jens, have you tried splitting your original patch into multiple smaller patches and just sampling the subregion you are interested in? E.g. creating a faceSet of the region of interest and then using createPatch to generate a patch from that faceSet? JensD likes this. __________________ If you liked my answer to your question, please consider leaving a "Like" in return

June 29, 2018, 08:28		#4
RobertHB Senior Member Robert Join Date: May 2015 Location: Bremen, GER Posts: 292 Rep Power: 12	Sounds like the way to go. The setSet utility has an action called subset that may be used for the operation of intersecting the two set. Another way may be creating the box set, and the cylinder set. Then substracting the cylinder from the box, leaving you will only faces that are not part of the cyclinder. Upon inverting this latest cellSet you should end up with only the faces belonging to your cylinder. __________________ If you liked my answer to your question, please consider leaving a "Like" in return

June 29, 2018, 09:48		#6
RobertHB Senior Member Robert Join Date: May 2015 Location: Bremen, GER Posts: 292 Rep Power: 12	Oh sorry, i should have mentioned that. My approach has to be followed before you run your simulation, so you get results for the newly created patch. __________________ If you liked my answer to your question, please consider leaving a "Like" in return

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June 29, 2018, 08:10		#3
JensD New Member Join Date: Mar 2015 Posts: 12 Rep Power: 11	Hi Robert Thanks for the response. This seems like a good method. On selecting the faces, I'm thinking of first selecting a faceSet with boxToFaces (box covering the region) and then make a subset of this with the pathToFace source to select only the faces that are on the wall patch. Would you advise this or do you have another way of tackling this?

June 29, 2018, 09:42		#5
JensD New Member Join Date: Mar 2015 Posts: 12 Rep Power: 11	I managed to create the patch, but I can't sample or visualize as the size of the patch in my polyMesh is now different from the one in my time steps. Do I need to do something similar to the simulation results (T, p, U, ...) to allow sampling of this subregion?