[boreal1]

Hi,

i want to calculate y+, Co and the wall shear stress and it works with the following controlDict:

/*--------------------------------*- C++ -*----------------------------------*\
|                                                                             |
|                Generated by the CfdOF workbench for FreeCAD                 |
|                      https://github.com/jaheyns/CfdOF                       |
|                                                                             |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

application     pimpleFoam;

startFrom       startTime;

startTime       0;

stopAt          endTime;

deltaT          0.1;

endTime         4.0;

writeControl    timeStep;

writeInterval   1;

purgeWrite      0;

adjustTimeStep  yes;

maxCo           5.0;

writeFormat     ascii;

writePrecision  8;

runTimeModifiable true;

libs
(
    // Needed for availability of porous baffle boundary in potentialFoam
    #include "turbulenceLib"
);

functions
{yPlus
{
    type            	yPlus;
    libs            	(fieldFunctionObjects);
    writeControl        writeTime;
	writeInterval		1;
   
}
 Co1
    {
	type                CourantNo;
	libs                ("libfieldFunctionObjects.so");
	writeControl      	writeTime;
	writeInterval     	1;
    }
	
shearStress
{
	type 				wallShearStress;
	libs 				("libfieldFunctionObjects.so");
	writeControl 		writeTime;
	writeInterval 		1;
}
}

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

The issue is that i want smaller time steps, because i need lower Courant numbers (btw, if you have any sources what Co for an LES should be, i would be glad, i'm finding contradicting information). Anyway, when I'm using the following script:

/*--------------------------------*- C++ -*----------------------------------*\
|                                                                             |
|                Generated by the CfdOF workbench for FreeCAD                 |
|                      https://github.com/jaheyns/CfdOF                       |
|                                                                             |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

application     pimpleFoam;

startFrom       startTime;

startTime       0;

stopAt          endTime;

deltaT          0.001;

endTime         4.0;

writeControl    timeStep;

writeInterval   0.01;

purgeWrite      0;

adjustTimeStep  yes;

maxCo           5.0;

writeFormat     ascii;

writePrecision  8;

runTimeModifiable true;

libs
(
    // Needed for availability of porous baffle boundary in potentialFoam
    #include "turbulenceLib"
);

functions
{yPlus
{
    type            	yPlus;
    libs            	(fieldFunctionObjects);
    writeControl        writeTime;
	writeInterval		0.01;
   
}
 Co1
    {
	type                CourantNo;
	libs                ("libfieldFunctionObjects.so");
	writeControl      	writeTime;
	writeInterval     	0.01;
    }
	
shearStress
{
	type 				wallShearStress;
	libs 				("libfieldFunctionObjects.so");
	writeControl 		writeTime;
	writeInterval 		0.01;
}
}

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

I'm receiving the error:

--> FOAM FATAL IO ERROR: (openfoam-2206)
writeInterval < 1 for writeControl timeStep

file: system/controlDict at line 16 to 72.

    From virtual void Foam::Time::readDict()
    in file db/Time/TimeIO.C at line 279.

Do you have any idea how to solve this issue?

[JNSN]

from the documentation:
writeControlControls the timing of write output to file.

• timeStep: Writes data every writeInterval time steps.

thus in case of timeStep for writeControl the interval must be an integer >= 1

[Yann]

Hello,

You can choose different writeControl parameters. In your case, you chose timeStep. It means you will save data to disk every X time step. This interval is defined by the writeInterval parameter.

If you have writeControl timeStep and writeInterval 5, data will be saved to disk every 5 time steps.

Now, you chose writeInterval 0.1, but solver solves time steps, you cannot save data every 0.1 time step because this data does not exist.

If you want to save data every 0.1s of physical time, you should use runTime or adjustableRunTime as writeControl.

Check the user guide to know more about this: https://www.openfoam.com/documentati...output-control

Cheers,
Yann