[nishant.kumar]

Hello all. I am trying to obtain values of pressure and velocity at certain time interval but the output time directories are not created at the specified writeInterval.

Here is the controlDict that I am using (based on the motorBike tutorial):

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.4.0                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

libs
(
    "libOpenFOAM.so"
    "libincompressibleTurbulenceModel.so"
    "libincompressibleRASModels.so"
);

application     simpleFoam;

startTime       0;

stopAt          endTime;

endTime         100;

deltaT          1;

writeControl    timeStep;

writeInterval   50;

purgeWrite      1;

writeFormat     binary;

writePrecision  6;

writeCompression compressed;

timeFormat      general;

timePrecision   6;

runTimeModifiable true;

functions
{   
    internalField
    {
        type            sets;
        libs            ("libsampling.so");
        enabled         true;

        interpolationScheme cellPoint;
        setFormat           raw;

        writeControl    adjustableRunTime;
        writeInterval   20;

        timeStart       20;
        timeEnd         80;

        fields  ( p U );
        points
        (
            #include "pointCloud.dat" // List of xyz coordinates
        );

        sets
        (
            cloud
            {
                type         cloud;
                axis         xyz;
                points       $points;
            }
        );
    }
}


// ************************************************************************* //

For this example, the output time directories are created as follows:

>> ls postProcessing/internalField/
20  21  22  23  24  25  26  27  28  29  
30  31  32  33  34  35  36  37  38  39  
40  41  42  43  44  45  46  47  48  49  
50  51  52  53  54  55  56  57  58  59  
60  61  62  63  64  65  66  67  68  69  
70  71  72  73  74  75  76  77  78  79  
80 100

As you can see, the interval of 20 is only applied when the two last time steps are saved (80 and 100). For the rest, the data is written every 1 time step.
This behavior remains the same for different values of writeInterval, timeStart and timeEnd that I played with.

How can I obtain the data only at the time periods defined by the writeInterval, that is at time steps 20,40,60... ?

[nishant.kumar]

The issue is resolved by modifying the sampling function as:

outputControl    adjustableRunTime;
outputInterval   20;