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-   -   Read gravity data varying with time (https://www.cfd-online.com/Forums/openfoam-programming-development/166134-read-gravity-data-varying-time.html)

shipman February 3, 2016 04:35
Read gravity data varying with time
 
Dear Foam users,

I would like to read the gravity values varying with time from a dataFile located in constant folder. As much as I searched, there is a close post here: http://www.cfd-online.com/Forums/ope...ty-time-2.html

In this post, iinterpolationTable<vector> is recommended which can be only used when the gravity values increase. However, I have random value depending on the time such as:
4
(
(0 (10 -5 0))
(0.1 (2 4 0))
(0.2 (-6 1.31 0))
(0.3 (21 0 0))
...
)

Is there anyone let me know how to read these gravity data varying with time.

Thank you in advance.

Mehrez February 3, 2016 09:49
Hi
Try to use the swak4Foam toolkit.
Mehrez

shipman February 4, 2016 19:09
Quote:
Originally Posted by Mehrez (Post 583563)
Hi
Try to use the swak4Foam toolkit.
Mehrez
Hi Mehrez,

Thank you very much for your reply. Actually, after looking at the interpolationTable code I found how to read the gravitation data from .dat file as follows:

Code:
interpolationTable<vector> Acc
(
    runTime.path()/runTime.caseConstant()/".dat"
);
  g.value()= Acc.(runTime.value());
If the .dat file is same with the time step (for example deltaT= 1)
4
(
(1 (1 5 4))
(2 (2 4 8))
...

above code works well. My another question is if my time step is 0.5 how can i make interpolation between these values given in .dat file.

Any advice will be appreciated.

Thank you

________
Moderator note: The following was also asked via PM:
Quote:
Originally Posted by shipman
As an addition to above question, I used interFoam and I would like to get the water height vs time. Do you think that is it possible?

wyldckat February 21, 2016 15:57
Quick answers @Baris: Sorry, I'm out of time for today and a bit grumpy/hungry, but nonetheless here goes:
  1. You should have stated which OpenFOAM or foam-extend version you're using! :rolleyes:
  2. You should have provided code that I could test with, along with a test case :(
  3. Instead of using the interpolation table, use "DataEntry": http://www.cfd-online.com/Forums/ope...tablefile.html
  4. Quote:
    Originally Posted by shipman
    As an addition to above question, I used interFoam and I would like to get the water height vs time. Do you think that is it possible?
    Sorry, but the question is too vague :( I need a lot more details, context and what exactly you're trying to "get". Either way, it's probably possible, I guess :confused:

federicabi June 9, 2016 04:58
Quote:
Originally Posted by shipman (Post 583777)
Hi Mehrez,

Thank you very much for your reply. Actually, after looking at the interpolationTable code I found how to read the gravitation data from .dat file as follows:

Code:
interpolationTable<vector> Acc
(
    runTime.path()/runTime.caseConstant()/".dat"
);
  g.value()= Acc.(runTime.value());
If the .dat file is same with the time step (for example deltaT= 1)
4
(
(1 (1 5 4))
(2 (2 4 8))
...

above code works well. My another question is if my time step is 0.5 how can i make interpolation between these values given in .dat file.

Any advice will be appreciated.

Thank you

________
Moderator note: The following was also asked via PM:

Hi Baris, hi Foamers
do you know how to apply the interpolationTable code to read the forces.dat file, that is updated every timestep, in run time?

Thanks in advice.

Federica


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