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-   -   plot over time (https://www.cfd-online.com/Forums/openfoam-post-processing/102254-plot-over-time.html)

fferroni May 26, 2012 11:02
plot over time
 
Hello everyone,

I'm trying to plot velocity magnitude fluctuations at a point, for thousands of time-steps, and then export them, fourier transform etc.

In paraview, I am aware that there is a 'plot over time' function. I select a point. However, I cannot seem to be able to plot velocity, only post-processed values like vorticity. Any ideas? I also tried using beforehand a cell-to-point filter but still no luck.

Thank you in advance!!!! I'm sure someone has done this before, because I can't think of many other ways to estimate fluctuation frequency...

Best Regards,

Francesco

amin144 May 26, 2012 12:23
Quote:
Originally Posted by fferroni (Post 363244)
Hello everyone,

I'm trying to plot velocity magnitude fluctuations at a point, for thousands of time-steps, and then export them, fourier transform etc.

In paraview, I am aware that there is a 'plot over time' function. I select a point. However, I cannot seem to be able to plot velocity, only post-processed values like vorticity. Any ideas? I also tried using beforehand a cell-to-point filter but still no luck.

Thank you in advance!!!! I'm sure someone has done this before, because I can't think of many other ways to estimate fluctuation frequency...

Best Regards,

Francesco
Hi
Could you explain me more
can you plot velocity over time or your problem is only about vorticity?

gschaider May 26, 2012 12:29
Quote:
Originally Posted by fferroni (Post 363244)
Hello everyone,

I'm trying to plot velocity magnitude fluctuations at a point, for thousands of time-steps, and then export them, fourier transform etc.

In paraview, I am aware that there is a 'plot over time' function. I select a point. However, I cannot seem to be able to plot velocity, only post-processed values like vorticity. Any ideas? I also tried using beforehand a cell-to-point filter but still no luck.

Thank you in advance!!!! I'm sure someone has done this before, because I can't think of many other ways to estimate fluctuation frequency...

Best Regards,

Francesco
What you're looking for is the probes functionObject. Searching for these two keywords you should find sufficient information

fferroni May 27, 2012 01:11
Indeed.

For reference to others, to extract probe data over time-steps after simulations:

Add a probesDict file to your system folder ( https://unihub.ru/tools/ofservice/br...bes/probesDict ) and run 'probeLocations'

Thank you!!

gschaider May 27, 2012 11:36
Quote:
Originally Posted by fferroni (Post 363280)
Indeed.
It's not that hard to find once you know the nomenclature, isn't it?

Quote:
Originally Posted by fferroni (Post 363280)
For reference to others, to extract probe data over time-steps after simulations:

Add a probesDict file to your system folder ( https://unihub.ru/tools/ofservice/br...bes/probesDict ) and run 'probeLocations'

Thank you!!
Would an entry in http://openfoamwiki.net/index.php/Ma...Postprocessing have helped you? In that case it would be nice if you wrote one

Ahmed Khattab June 8, 2012 04:16
Quote:
Originally Posted by fferroni (Post 363280)
Indeed.

For reference to others, to extract probe data over time-steps after simulations:

Add a probesDict file to your system folder ( https://unihub.ru/tools/ofservice/br...bes/probesDict ) and run 'probeLocations'

Thank you!!
Hi,

i vave tried this method but that is only i got
Code:
Create time

Create mesh for time = 0

Time = 0

Time = 1

Time = 2

Time = 3

Time = 4

Time = 5

Time = 6

Time = 7

Time = 8

Time = 9

Time = 10

Time = 11

Time = 12

Time = 13

Time = 14

Time = 15

Time = 16

Time = 17

Time = 18

Time = 19

Time = 20

Time = 21

Time = 22

Time = 23

Time = 24

Time = 25

Time = 26

Time = 27

Time = 28

Time = 29

Time = 30

Time = 31

Time = 32

Time = 33

Time = 34

Time = 35

Time = 36

Time = 37

Time = 38

Time = 39

Time = 40

Time = 41

Time = 42

Time = 43

Time = 44

Time = 45

Time = 46

Time = 47

Time = 48

Time = 49

Time = 50

Time = 51

Time = 52

Time = 53

Time = 54

Time = 55

Time = 56

Time = 57

Time = 58

Time = 59

Time = 60

Time = 61

Time = 62

Time = 63

Time = 64

Time = 65

Time = 66

Time = 67

Time = 68

Time = 69

Time = 70

Time = 71

Time = 72

Time = 73

Time = 74

Time = 75

Time = 76

Time = 77

Time = 78

Time = 79

Time = 80

Time = 81

Time = 82

Time = 83

Time = 84

Time = 85

Time = 86

Time = 87

Time = 88

Time = 89

Time = 90

Time = 91

Time = 92

Time = 93

Time = 94

Time = 95

Time = 96

Time = 97

Time = 98

Time = 99

Time = 100

End
no values displayed.

my probesDict file is:
Code:
    /*--------------------------------*- C++ -*----------------------------------*\
    | =========                |                                                |
    | \\      /  F ield        | OpenFOAM: The Open Source CFD Toolbox          |
    |  \\    /  O peration    | Version:  2.0.1                                |
    |  \\  /    A nd          | Web:      www.OpenFOAM.com                      |
    |    \\/    M anipulation  |                                                |
    \*---------------------------------------------------------------------------*/
    FoamFile
    {
        version    2.0;
        format      ascii;
        class      dictionary;
        object      probesDict;
    }
    // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
   
    // Fields to be probed. runTime modifiable!
    fields
    (
        u
    );
   
    // Locations to be probed. runTime modifiable!
    probeLocations
    (
        (0  0.5 0.0)
            (0.2 0.5 0.0)
            (0.4 0.5 0.0)
            (0.6 0.5 0.0)
            (0.8 0.5 0.0)
            (1.0 0.5 0.0)

    );
   
    // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
thanks in advance.

gschaider June 8, 2012 05:09
Quote:
Originally Posted by rebel ahmed (Post 365403)
Hi,

i vave tried this method but that is only i got
Code:
Create time

Create mesh for time = 0

Time = 0

....

Time = 100

End
no values displayed.
Is better. Use "ls" and look for the saved data

eysteinn June 8, 2012 07:56
Quote:
Originally Posted by rebel ahmed (Post 365403)
my probesDict file is:
Code:
    /*--------------------------------*- C++ -*----------------------------------*\
    | =========                |                                                |
    | \\      /  F ield        | OpenFOAM: The Open Source CFD Toolbox          |
    |  \\    /  O peration    | Version:  2.0.1                                |
    |  \\  /    A nd          | Web:      www.OpenFOAM.com                      |
    |    \\/    M anipulation  |                                                |
    \*---------------------------------------------------------------------------*/
    FoamFile
    {
        version    2.0;
        format      ascii;
        class      dictionary;
        object      probesDict;
    }
    // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
   
    // Fields to be probed. runTime modifiable!
    fields
    (
        u
    );
   
    // Locations to be probed. runTime modifiable!
    probeLocations
    (
        (0  0.5 0.0)
            (0.2 0.5 0.0)
            (0.4 0.5 0.0)
            (0.6 0.5 0.0)
            (0.8 0.5 0.0)
            (1.0 0.5 0.0)

    );
   
    // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Hi,
I think replacing u with U, for velocity, will do the trick!
followed then by the ls probes trick :)

/Eysteinn


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