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-   -   How to calculate the water height | Water Surface Elevation | interFOAM (https://www.cfd-online.com/Forums/openfoam-post-processing/116103-how-calculate-water-height-water-surface-elevation-interfoam.html)

pythag0ra5 April 12, 2013 18:35

How to calculate the water height | Water Surface Elevation | interFOAM
 
Dear FOAMers,

i made a simulation with interFoam and want to do some post-processing now. My channel is 2m long, and i want to make a diagram, where the water height (alpha = 0.5) is plotted over the channel length.

I tried to play around with "Plot over Line", but this seems not to be the right approach.

In a second step, i want to make a diagram of the Froude-Number along the channel. I want to define the Fr-Number as a new variable, but therefore i also need the water height.

Thank you very much in advance!

Best regards,
Mathias

wyldckat April 14, 2013 13:50

Greetings Mathias,

Sorry, I don't have much time to explain, so I'll refer you to a post I made some time ago: http://www.cfd-online.com/Forums/par...tml#post405615 post #2

I think you can sort out several ideas from that post ;)

Best regards,
Bruno

pythag0ra5 April 15, 2013 13:49

Dear Bruno,

thank you very much for your reply! In order to have a good "recipe" for the future, i want to list the steps i performed:
  • Make a contour of alpha1=0.5
  • Make a "Slice" which corresponds to the contour made above
  • Make a spreadsheet" view and export all data as a csv-file
  • In this file, all necessary data is included an can be visualized with GNU-Plot / Excel / whatever
Thank you very much!

ngj April 16, 2013 02:31

Hi Mathias,

You could also apply the surfaceElevation tool, which is distributed along with waves2Foam. More details can be found here:

http://openfoamwiki.net/index.php/Co...rfaceElevation

and download instructions here:

http://openfoamwiki.net/index.php/Co...d_Installation

This utility also allows for runTime sampling of the free surface, hence you can have a higher frequency in the sampling compared to the information written into the time folders.

Kind regards,

Niels

pythag0ra5 April 16, 2013 08:12

Hi Niels,

thank you very much for this intersting hint, i will try it!

Best regards,
Mathias

giack April 20, 2013 12:00

Hi to all,
I follow the procedure proposed by wyldckat but when I aplly the filter Plot Selection over Time appear this error:

p, li { white-space: pre-wrap; } ERROR: In /home/opencfd/OpenFOAM/ThirdParty-2.1.x/ParaView-3.12.0/VTK/Filtering/vtkTable.cxx, line 353
vtkTable (0xc3dcaa8): Column "vtkValidPointMask" must have 73 rows, but has 81.




ERROR: In /home/opencfd/OpenFOAM/ThirdParty-2.1.x/ParaView-3.12.0/VTK/Filtering/vtkTable.cxx, line 353
vtkTable (0xc3dcaa8): Column "Time" must have 73 rows, but has 81.




ERROR: In /home/opencfd/OpenFOAM/ThirdParty-2.1.x/ParaView-3.12.0/VTK/Filtering/vtkTable.cxx, line 353
vtkTable (0xc3dcaa8): Column "Point Coordinates (0)" must have 73 rows, but has 81.




ERROR: In /home/opencfd/OpenFOAM/ThirdParty-2.1.x/ParaView-3.12.0/VTK/Filtering/vtkTable.cxx, line 353
vtkTable (0xc3dcaa8): Column "Point Coordinates (1)" must have 73 rows, but has 81.




ERROR: In /home/opencfd/OpenFOAM/ThirdParty-2.1.x/ParaView-3.12.0/VTK/Filtering/vtkTable.cxx, line 353
vtkTable (0xc3dcaa8): Column "Point Coordinates (2)" must have 73 rows, but has 81.




ERROR: In /home/opencfd/OpenFOAM/ThirdParty-2.1.x/ParaView-3.12.0/VTK/Filtering/vtkTable.cxx, line 353
vtkTable (0xc3dcaa8): Column "Point Coordinates (Magnitude)" must have 73 rows, but has 81.


Moreover the plot of H is an horizontal line (I'm not understand this result).


What is the error that appear?
There is a way to plot the Froude number (or the velocity) of the front of an air bubble that move forward along the channel?
thank to all



amir_kb June 28, 2014 09:11

Hi everybody.
I have a problem like giack,(last question).:(
any idea would be helpful.
thanks to all.

wyldckat August 16, 2014 07:53

Greetings to all!

@Amir: Unfortunately back then I didn't have enough time to ask giack for more information, so I have to ask you now: please provide more details, so that I can try and reproduce the same error message.
Otherwise, without being able to reproduce the error, I'm not able to diagnose the problem and to provide a solution for it :(

Best regards,
Bruno

Mastra December 9, 2015 06:36

Greetings to all,

I am also still facing the problem of Giack concerning the vtkTable column "Time" with the 'Plot Selection Over Time' functionality. (Using paraView 2.12.0)

The error reads:

vtkTable (0x548f540): Column "vtkValidPointMask" must have 569 rows, but has 570

vtkTable (0x548f540): Column "Time" must have 569 rows, but has 570


Usually the 'Plot Selection Over Time' functionality works more or less ok, but when i cancel the calculation and restart the solver for a new timeStep this problem occurs. In this case the Column "Time" of vtkTable (0x548f540) does not update to the new timeStep (1 row more than before). If i delete the last time step 'Plot Selection over Time' works fine again.

Does somebody know how to update the vtktable manually for the new timStep or how to fix this error ?

Best regards,
Markus

wyldckat December 9, 2015 18:46

Quote:

Originally Posted by Mastra (Post 576922)
but when i cancel the calculation and restart the solver for a new timeStep this problem occurs.

Quick question: Can you please provide more details on how I can try to reproduce this exact same error? For example, with one of OpenFOAM's tutorials?

Because I suspect that when you cancel the calculation, you might hit the Ctrl+C key combination at the exact moment the solver is still writing to disk the fields for the latest time step. The other possibility is if there is one strange unexpected error in how the solver is continuing the simulation, for example it might delete files that it should not delete. This is why I ask for more details on how to reproduce the error.

As for a way to control the time ranges: menu "Edit -> Animation Controls", if I remember correctly. The widget that appears will give you controls for changing how the time steps are performed, either based on real time, or frames or specific time steps.

fluid126 March 17, 2016 04:09

plot surfaceElevation.dat
 
Hi, Niels, I am using your wave generation toolbox wave2Foam. In one of the tutorials, bejiBattjes, the surfaceElevation.dat is obtained after run. Could somebody tell me how to plot the surfaceElevation versus time ? Thank you.
Quote:

Originally Posted by ngj (Post 420811)
Hi Mathias,

You could also apply the surfaceElevation tool, which is distributed along with waves2Foam. More details can be found here:

http://openfoamwiki.net/index.php/Co...rfaceElevation

and download instructions here:

http://openfoamwiki.net/index.php/Co...d_Installation

This utility also allows for runTime sampling of the free surface, hence you can have a higher frequency in the sampling compared to the information written into the time folders.

Kind regards,

Niels



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