About the result file of Syrthes

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Jundi He
Posts: 98
Joined: Fri Jan 13, 2017 3:23 pm

About the result file of Syrthes

Post by Jundi He » Thu Feb 02, 2017 12:50 pm

Hi:

After I run the simulation of Syrthes, I need to correspond the global numbers of the nodes with the result temperature. I open the resu1.res file, there are 27472 temperatures and I have 27472 nodes. I have 2 questions:

1. I have 27472 nodes, is the nodes' global number from 1 to 27472 ? Or it's just some random numbers?
2. How did the temperatures in the result file match the global numbers of the nodes? For example, are the 6 temperatures in the first line represent the temperatures of node (global number) 1,2,3,4,5 and 6 ?

In order to upload the file, I convert the resu1.res file into resu1.txt.

Thanks!

Best Regards!
Jundi He
Attachments
resu1.txt
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Luciano Garelli
Posts: 229
Joined: Fri Dec 04, 2015 1:42 pm

Re: About the result file of Syrthes

Post by Luciano Garelli » Thu Feb 02, 2017 2:57 pm

Hello Jundi He,

Syrthes (conduction problem) is based on Finite Elements Method (FEM), while code saturne uses finite volumes (FVM). In FEM the unknow (temperature) are in the nodes, not in the cell center like in FVM.

The global numeration of nodes goes from 1 to the total number of nodes and it is used to create a conectivity list which specify which nodes forms every element. Also you can check the number of nodes in Salome or Paravis. In the file that you attached, each of these values correspond to the temperature of the node in a ordered way as you mention in the second question. In Paravis you can select a node, get the node ID, the temperature and compare with the temperature value in this file (Be careful because I think that paravis uses Zero-based numbering).

Regards,

Luciano

Jundi He
Posts: 98
Joined: Fri Jan 13, 2017 3:23 pm

Re: About the result file of Syrthes

Post by Jundi He » Thu Feb 02, 2017 4:55 pm

Hi:

Thanks for the answer! So the global number of the nodes and elements are given by Salome, not Syrthes, is it? Because Syrthes has convert the mesh file to syr, the format that can be read by Syrthes. So the convert only give the reference number of surface and volume groups, is it?

I have another question about Syrthes. If I am going to specify the global number of all the nodes in one surface (for example the reference number of the face is 16), put them into an array, which function can I use in the script of Syrthes? Thank you very much.

Best Regards!
Jundi He

Luciano Garelli
Posts: 229
Joined: Fri Dec 04, 2015 1:42 pm

Re: About the result file of Syrthes

Post by Luciano Garelli » Thu Feb 02, 2017 5:17 pm

Hello,

The numbering of nodes and connectivity elements are given by the mesh generator (netgen, gmesh, etc.), but a format conversion (med-> syr) is needed, changing the way in which the information it is stored and organized and be able to be readed by syrthes.

In don't understantd very well your second question. Why do you want to change the global node numbering on a face? Do you want to extract only the temperature of these nodes?

Regards,

Luciano

Jundi He
Posts: 98
Joined: Fri Jan 13, 2017 3:23 pm

Re: About the result file of Syrthes

Post by Jundi He » Thu Feb 02, 2017 5:46 pm

Hi:

Thanks for the reply. Yes, I want to extract the temperature of the nodes on one surface, so first I need to know the global number of all the nodes on this surface, and then I can extract the temperature of these nodes by the resu1.res file.

Best Regards!
Jundi He

Luciano Garelli
Posts: 229
Joined: Fri Dec 04, 2015 1:42 pm

Re: About the result file of Syrthes

Post by Luciano Garelli » Thu Feb 02, 2017 7:28 pm

Hello,

In the section "Running options" of Syrthes you have the "Advanced Options" and you can choose "Convert results for software" Ensight/Paraview. This will convert the *.res to *ensight.case. Then you can open in Paravis and apply the filter ExtractSurface and then ExtractBlock. This will allow to extract the desired surface. After that you can "Save Data" in paravis to a CSV file with the temperature and the points coordinates.

Regards,

Luciano.

Jundi He
Posts: 98
Joined: Fri Jan 13, 2017 3:23 pm

Re: About the result file of Syrthes

Post by Jundi He » Fri Feb 03, 2017 2:36 pm

Luciano:

Many thanks for the helping!

Regards!
Jundi He

Jundi He
Posts: 98
Joined: Fri Jan 13, 2017 3:23 pm

Re: About the result file of Syrthes

Post by Jundi He » Fri Feb 03, 2017 3:07 pm

Luciano:

I still need to output the ID of all the nodes in a surface as an array in a file, because I need to use the temperature of the surface nodes to do some calculations, and update the boundary conditions of the surface, and run the simulation again (iteration), is there any methods that I can do that? Thank you very much!

Regards!
Jundi He

Jundi He
Posts: 98
Joined: Fri Jan 13, 2017 3:23 pm

Re: About the result file of Syrthes

Post by Jundi He » Fri Feb 03, 2017 3:45 pm

Hi:

I've selected a face in Salome and export it as dat file, and open it, there seems to be the ID number of the nodes and its corresponding coordinates, is it correct? I just want to make sure that the first number of each line is the ID number of the nodes. Thanks!

Regards!
Jundi He

Luciano Garelli
Posts: 229
Joined: Fri Dec 04, 2015 1:42 pm

Re: About the result file of Syrthes

Post by Luciano Garelli » Fri Feb 03, 2017 4:24 pm

Hello,

Yes, using Salome you can export a mesh surface as a *.DAT file, in the first line you get the number of nodes and the number of element, then the list of nodes (global node ID , coordinates) and then the list of elements (global element ID, conectivities).

Also, you can do it using Paravis and I think that is more convenient because the ids and temperature use the same ordering criterion. Load the result file, apply a "Generate Id" filter, then "ExtractSurface", "ExtractBlock" and "Save data". This will give a file with the (global node ID , coordinates). After that, remove the "Generate Id" and "Save data" to get the temperature field. Now, you can merge this two file and get (global node ID , coordinates, temperature)

Regards,

Luciano

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