[nahian_masud]

I am attaching the case file. Whenever i try to run, it shows the error.
(attached below)
277999892_1089769345204759_900859964713374417_n.jpg

277959553_2840606089574810_867235461933461332_n.jpg

I tried to run the simulation with
" mpirun -np 2 pimpleFoam -parallel " as I have decomposed 2 processors.

no velocity is known. the inlet and outlet pressure are defined in the P file

the 0/U

/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 8
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volVectorField;
object U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 1 -1 0 0 0 0];

internalField uniform (0 0 0);

boundaryField
{
inlet
{
type zeroGradient;

}

outlet
{
type zeroGradient;
}

wall
{
type fixedValue;
value uniform (0 0 0);
}
}

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

the 0/P
/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 8
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
object p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 2 -2 0 0 0 0];

internalField uniform 0;

boundaryField
{
inlet
{
type fixedValue;
value uniform 101325;
}

outlet
{
type fixedValue;
value uniform 86000;
}

wall
{
type zeroGradient;
}
}

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

the controldict file
/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 8
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "system";
object controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

application pimpleFoam;

startFrom startTime;

startTime 0;

stopAt endTime;

endTime 1000;

deltaT 0.2;

writeControl timeStep;

writeInterval 200;

purgeWrite 0;

writeFormat ascii;

writePrecision 6;

writeCompression off;

timeFormat general;

timePrecision 6;

runTimeModifiable true;

functions
{
#includeFunc fieldAverage(U, p, prime2Mean = yes)
}

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

[SHUBHAM9595]

Hi nahian_masud,

Welcome to the forum.

Hope u already solved the problem....If not, based on the limited info provided in the post......few suggestions

1) change the

internalField   uniform 0;

to

internalField   uniform 101325;

2) From the log file we can see the courant number is too high....maybe you can do checkMesh to see if everything is fine....If so, then you can start with smaller deltaT magnitudes....and then allow solver to choose the optimum deltaT based on maximum allowed Courant number....by adding following

adjustTimeStep  true;

maxCo           1;

in the controlDict



Another kind suggestion :- From next time onwards, please try to ask the questions in the respective subsections of the forum...for ex : Meshing related things can be asked in https://www.cfd-online.com/Forums/openfoam-meshing/, case running & solving in (https://www.cfd-online.com/Forums/openfoam-solving/).....then your question will have more visibility and thus a faster response.


Regards,
Shubham