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Creating an average line in paraView

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Old   October 7, 2010, 08:01
Exclamation Creating an average line in paraView
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Hello Users,

i have finished a simulation in OpenFoam which gets the wallShearStress over the surface. In paraFoam i can see all wallShearStresses over the whole object-surface.
Now my question: Can I lay a line over my model which gives the average of the wallShearStresses in paraView? How can i realise that in paraView? Is there a tool, for example that draws a line in x-direction over the model and gives the average of the wallShearStresses on this line?

Best regards,
Roland
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Old   October 17, 2010, 14:33
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I have found it in the meantime.
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Old   October 17, 2010, 16:30
Default how does that work again?
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Quote:
Originally Posted by kayoneex View Post
I have found it in the meantime.
Could you share your procedure?
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Old   October 20, 2010, 07:18
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Of course.

- Load your model in paraView.
- There is a tool called PlotOverLine. (Filters - Data Analysis)
- Now you can make a 2D-Line with the coordinatesyou need.
- Apply. paraView builds a graph (U or P etc..), where your sampled data is written in.
- Use the tool IntegrateVariables (Filters - Alphabetical) to get the average of this graph

Hopefully it can help.

Roland
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Old   October 22, 2010, 10:27
Default Average Line in Paraview
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Hello kayoneex,

I am trying to get average velocity over a region and did as you suggested. However, I am not sure, that it is giving me the right values. The line is generated parallel to the x-axis at a certain y-coordinate. So, I suppose the velocity graph that I am getting is of the Ux velocity (most dominant in my case, one order of magnitude higher than Uy and Uz) in this region.

The graph that I have created using PlotOverLine gave me the following result, which is in the first graph. As you can see, the average velocity (Ux) will be in the region of 1.5. However, when I run the IntegrateVariables, I get the table, where the value of Ux is reported as 0.7932.

Am i missing something?
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Of course.

- Load your model in paraView.
- There is a tool called PlotOverLine. (Filters - Data Analysis)
- Now you can make a 2D-Line with the coordinatesyou need.
- Apply. paraView builds a graph (U or P etc..), where your sampled data is written in.
- Use the tool IntegrateVariables (Filters - Alphabetical) to get the average of this graph

Hopefully it can help.

Roland
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Old   October 22, 2010, 10:59
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Hello subhkirti,

yes that is my problem too. If you look at the field, that is generated when you use Integrate Variables, you get Ux, Uy and Uz. I tried to it with the formula squr(Ux+Uy+Uz), but in my case the Uy is the dominant.
In my case it the average is in the same direction, but not exactly it. Maybe somebody can help with that problem...
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Old   October 25, 2010, 06:11
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@subhkirti
I tried something... IntegrateVariables gives a magnitude about 0.13 for my wallShearStress. If i look at my graph it must be around 0.06-0.07.
I typed all magnitudes ( in my case 100), you get them from PlotOverline, in Excel. With AVERAGE(A1-A100) you get the average from wallShearStress or in your Case Ux. In my case ist is about 0.066. So its right.
Now my question:
Is there an oportunity to export all magnitudes from paraView in Excel????
Or can i get the average from my magnitudes somehow with the calculator in paraView????

Please help
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Old   October 25, 2010, 07:45
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export: click on the plotOverLine-magnitudes.
then file, export save as .csv-file.
you can open this file with excel.

edit the .csv-file:
- data
- text in cleaving
- cutting comma
- replace comma with point , with .
- in an empty cell: average (...-...)
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Old   October 25, 2010, 09:30
Default Paraview Export function
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Well, I am having a problem there. My export option is disabled when I am using the plotOverLine. How did you do it? I tried it exactly as you mentioned it, but something is missing i guess.

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Originally Posted by kayoneex View Post
export: click on the plotOverLine-magnitudes.
then file, export save as .csv-file.
you can open this file with excel.

edit the .csv-file:
- data
- text in cleaving
- cutting comma
- replace comma with point , with .
- in an empty cell: average (...-...)
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Old   October 25, 2010, 11:38
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Do you see your magnitudes in a list?
At the window of the PlotOverLine-graph in the upper right corner, there is a field called split horizontal. Click on it. Now you got a few options. Take the one which generates your magnitudes. It is one of the lower options.

Choose the whole magnitudes and click at Data - export ......

It must work...
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Old   October 26, 2010, 05:23
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name of the option is: Spreadsheet View
and then in the showing-field: PlotOverLine
now you must see your magnitudes
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