[kaszt]

I'm having an issue with OpenFOAM writing data every time step. I'm using pimpleFoam with a max Courant number of 5, so I'm trying to take advantage of adjusting the time step to meet this criteria and speed things up a bit. But the problem is that no matter what scalar value I set "writeInterval" to, OF writes data every time step. Here is my controlDict file:

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  3.0.1                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "system";
    object      controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

application     pimpleFoam;

startFrom       startTime;

startTime       0;

stopAt          endTime;

endTime         5; 

deltaT          0.01; 

writeControl    adjustableRunTime;

writeInterval   100;

purgeWrite      0;

writeFormat     ascii;

writePrecision  12; 

writeCompression off;

timeFormat      general;

timePrecision   12;

runTimeModifiable true;

adjustTimeStep  yes;

maxCo           5; 

functions
{
    forces
    {
        type        forces;
        functionObjectLibs  ("libforces.so");
        writeControl   timeStep;
        writeInterval  1;
        patches     (fixedWalls);
        
        pName       p;
        UName       U;
      
        rho	    rhoInf; 
        rhoInf      1.205; 
        log         true;
        CofR        (0 0 0); // origin for moment calculation
        
        writeFields yes;
        
        binData
        {
            nBin    90; //output data into 20 bins
            direction   (1 0 0); // bin direction
            format  gnuplot;
            cumulative  yes;
        }
    }


    forceCoefficients
    {
        type        forceCoeffs;
        functionObjectLibs  ("libforces.so");
        writeControl   timeStep;
        writeInterval  1;
        patches     (fixedWalls);
        
        writeFields yes;
        
        log         true;
        patches     (fixedWalls); // on cyl only
        pName       p;
        UName       U;
        dragDir     (1 0 0);
        liftDir     (0 1 0);
        pitchAxis   (0 0 1);
        CofR        (0 0 0);
        magUInf     10; // free stream velocity; inlet condition!!
        lRef        1;
        Aref        0.79; // cross sectional area
    
        rho	    rhoInf;
        rhoInf      1; 
        origin      (0 0 0);
    
        coordinateRotation
        {
            type        EulerRotation
            degrees     true;
            rotation    (0 0 0);
        }
        
        binData
        {
            nBin    90; //output data into 20 bins
            direction   (1 0 0); // bin direction
            format  gnuplot;
            cumulative  yes;
        }
    }
}
// ************************************************************************* //

It is to my understanding from the documentation that OF will write data every (writeInterval)*(deltaT) of simulation time. However, this case writes every time step. Changing the writeInterval scalar doesn't change this, nor does changing the method of writeControl (I've tried using timeStep and runTime, and both yield the same result). I have neither the desire nor the space to write every time step, so any tips would be greatly appreciated!

NOTE: I am running OpenFOAM-v1706 released here with Ubuntu 16.04.

[sheaker]

Hi.
There is endTime set to 5 while writeInterval set to 100. I would set writeInterval to 0.1 or something like that. Maybe this solve Your problem.

[ykanani]

Hi,
When you select

 writeControl    adjustableRunTime;

Then the value of writeInterval is the simulation time itself. In this case, it is NOT the number of iterations.

So first, as Oskar said, reduce the writeIntervals to a value less than your endTime. Anyways, this should not be the main issue. Since with your current config no time step should be saved.


I think it has something to do with your functionObjects. Please first remove them and verify that write behavior is resolved. Then, try setting writeFields to No in your functionObjects.

Regards,

[kaszt]

You are right Yousef; the problem was with my functionObjects. Removing them resolved the write behavior, and then including them and setting writeFields to "no" works as intended. Thank you both for your help!

[fsifsi]

Hello Alls,
I use OF1812
in system/control
....
writeControl adjustableRunTime;
writeInterval 0.1071;
.....
and system/forces
.....
writeControl timeStep ;
writeInterval 10;
.....
OF writes every time step even though I change value of " writeInterval 10; "
So, appreciated your comments !

[HPE]

Hi,

- Could you please share the `controlDict` and `force*` file entirely?
- What does OF write out at each time-step? `force` FO information or something else?
- Have you double checked the log file if the `force` FO is written every time-step? May be the time-step is tiny, and you misinterpreted what is going on?

thanks

[chc]

For anyone coming across this in the future, I was dealing with a similar issue. One way of controlling your probes is by including the “executeControl” and “executeInterval” settings. For some reason this helps write at the expected interval instead of some other case, though I have found issues trying to use non integer values when using writeTime as the control. timeStep seems to be a better option for that.