[surajkvs]

My solver Pressure residual is not getting converged event after 100000 iterations,The value of residual remains between 0.1 and 1.0 . And I want it in below 0.001 atleast.What could be the possible reasons.
What changes should I do.
I am using MPPICFoam .

my details of setting file is as below-
Please suggest me chages,I tried with changing Mesh size.deltaT but unable to get.My solver is working very slow.

BlockMeshDict-
--------------------------------------------------------------------
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

convertToMeters 1;

vertices
(
(0 0 0) //0
(0.05 0 0) //1
(0.05 0.0001 0) //2
(0 0.0001 0) //3
(0 0 2.79) //4
(0.05 0 2.79) // 5
(0.05 0.0001 2.79) //6
(0 0.0001 2.79) //7
);

blocks
(
hex (0 1 2 3 4 5 6 7) (50 3 1200) simpleGrading (1 1 1)
);

edges
(
);

boundary
(
top
{
type patch;

faces ((4 5 6 7));
}

bottom
{
type patch;

faces ((0 1 2 3));
}


walls
{
type wall;

faces
(
(1 2 6 5)
(3 0 4 7)
);

}


front
{
type cyclic;
neighbourPatch back;
faces ((0 1 5 4));
}

back
{
type cyclic;
neighbourPatch front;
faces ((2 3 7 6));
}


);
mergePatchPairs
(
);
// ************************************************** *********************** //






ControlDict

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

application MPPICFoam;

startFrom latestTime;

startTime 0;

stopAt endTime;

endTime 100;

deltaT 2e-4;

writeControl adjustableRunTime;

writeInterval 0.1;

purgeWrite 0;

writeFormat ascii;

writePrecision 6;

writeCompression uncompressed;

timeFormat general;

timePrecision 6;

runTimeModifiable yes;


functions
{
fieldAverage1
{
type fieldAverage;
functionObjectLibs ( "libfieldFunctionObjects.so" );
resetOnRestart false;
outputControl outputTime;//runTime;//timeStep;
//writeInterval 0.05;
timeStart 10.0;
//timeEnd 0.5;
resetOnOutput false;

fields
(

U.air
{
mean on;
prime2Mean off;
base time;
}

alpha.air
{
mean on;
prime2Mean off;
base time;
}

p
{
mean on;
prime2Mean off;
base time;
}



);
}
}


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





Fvschemes

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

ddtSchemes
{
default CrankNicolson 0.8;
}

gradSchemes
{
default Gauss linear;
}

divSchemes
{
default none;

div(alphaPhic,U.air) Gauss linearUpwindV unlimited;
div(((alpha.air*nuEff.air)*dev2(T(grad(U.air))))) Gauss linear;

div(phiGByA,kinematicCloud:alpha) Gauss linear;
div(alphaPhic,epsilon.air) Gauss limitedLinear 1;
div(alphaPhic,k.air) Gauss limitedLinear 1;
}

laplacianSchemes
{
default Gauss linear corrected;
}

interpolationSchemes
{
default linear;
}

snGradSchemes
{
default corrected;
}


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



fvSolutions-

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

solvers
{
p
{
solver GAMG;
tolerance 1e-06;
relTol 0.01;
smoother GaussSeidel;
}

pFinal
{
solver GAMG;
tolerance 1e-06;
relTol 0;
smoother GaussSeidel;
}

"(U|k|epsilon|omega).air"
{
solver smoothSolver;
smoother symGaussSeidel;
tolerance 1e-05;
relTol 0.1;
}

"(U|k|epsilon|omega).airFinal"
{
solver smoothSolver;
smoother symGaussSeidel;
tolerance 1e-05;
relTol 0.1;
}

kinematicCloud:alpha
{
solver GAMG;
tolerance 1e-06;
relTol 0.1;
smoother GaussSeidel;
}
}

PIMPLE
{
nOuterCorrectors 1;
nCorrectors 2;
momentumPredictor yes;
nNonOrthogonalCorrectors 0;
pRefCell 0;
pRefValue 0;
}

relaxationFactors
{
equations
{
".*" 0.7;
}
}


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