[sam.ho]

Hi
I am simulating a flow valve with following parameters
Density = 830 [kg/m3]
Viscosity = 8.26e-06 [kg/m.s]
Mass Flow rate = 145 lph (litres per hr)
Re=1.87202 X 10^5
The valve has one inlet and 4 outlets.
The boundary conditions are as follow

U file
[dimensions [0 1 -1 0 0 0 0];

internalField uniform (0 0 0);

boundaryField
{
INLET
{
type flowRateInletVelocity;
volumetricFlowRate constant 40.6e-6;
value uniform (0 0 0);
}

OUTLET_1
{
type inletOutlet;
value uniform (0 0 0);
inletValue uniform (0 0 0);
}
OUTLET_2
{
type inletOutlet;
value uniform (0 0 0);
inletValue uniform (0 0 0);
}
OUTLET_3
{
type inletOutlet;
value uniform (0 0 0);
inletValue uniform (0 0 0);
}
OUTLET_4
{
type inletOutlet;
value uniform (0 0 0);
inletValue uniform (0 0 0);
}
WALL_VALVE
{
type fixedValue;
value uniform (0 0 0);
}
WALL_SPRING
{
type fixedValue;
value uniform (0 0 0);
}
WALL_HOUSING
{
type fixedValue;
value uniform (0 0 0);
}
WALL_SPRING_SUPPORT
{
type fixedValue;
value uniform (0 0 0);
}
}

// ************************************************** *********************** //]

p file
[CODE]
[dimensions [0 2 -2 0 0 0 0];

internalField uniform 0;

boundaryField
{
INLET
{
type zeroGradient;
}
OUTLET_1
{
type fixedValue;
value $internalField;
}
OUTLET_2
{
type fixedValue;
value $internalField;
}
OUTLET_3
{
type fixedValue;
value $internalField;
}
OUTLET_4
{
type fixedValue;
value $internalField;
}

WALL_VALVE
{
type zeroGradient;
}
WALL_SPRING
{
type zeroGradient;
}
WALL_HOUSING
{
type zeroGradient;
}
WALL_SPRING_SUPPORT
{
type zeroGradient;
}


}

// ************************************************** *********************** //]

k file
[CODE]
[dimensions [ 0 2 -2 0 0 0 0 ];

internalField uniform 0.0001133785;

boundaryField
{
INLET
{
type turbulentIntensityKineticEnergyInlet;
intensity 0.0322;
value uniform 0.0001133785;
}

OUTLET_1
{
type inletOutlet;
inletValue uniform 0.0001133785;
value uniform 0.0001133785;
}
OUTLET_2
{
type inletOutlet;
inletValue uniform 0.0001133785;
value uniform 0.0001133785;
}
OUTLET_3
{
type inletOutlet;
inletValue uniform 0.0001133785;
value uniform 0.0001133785;
}
OUTLET_4
{
type inletOutlet;
inletValue uniform 0.0001133785;
value uniform 0.0001133785;
}

WALL_VALVE
{
type kqRWallFunction;
value uniform 0.0001133785;
}
WALL_SPRING
{
type kqRWallFunction;
value uniform 0.0001133785;
}
WALL_HOUSING
{
type kqRWallFunction;
value uniform 0.0001133785;
}
WALL_SPRING_SUPPORT
{
type kqRWallFunction;
value uniform 0.0001133785;
}

}


// ************************************************** *********************** //]
Epsilon file
[CODE]
[dimensions [ 0 2 -3 0 0 0 0 ];

internalField uniform 0.01533;

boundaryField
{

INLET
{
type turbulentMixingLengthDissipationRateInlet;
mixingLength 0.001; // This is based on diameter
value uniform 0.0153;
}

OUTLET_1
{
type inletOutlet;
inletValue uniform 0.0153;
value uniform 0.0153;
}
OUTLET_2
{
type inletOutlet;
inletValue uniform 0.0153;
value uniform 0.0153;
}
OUTLET_3
{
type inletOutlet;
inletValue uniform 0.0153;
value uniform 0.0153;
}
OUTLET_4
{
type inletOutlet;
inletValue uniform 0.0153;
value uniform 0.0153;
}
WALL_VALVE
{
type epsilonWallFunction;
value uniform 0.0153;
}

WALL_SPRING
{
type epsilonWallFunction;
value uniform 0.0153;
}

WALL_HOUSING
{
type epsilonWallFunction;
value uniform 0.0153;
}

WALL_SPRING_SUPPORT
{
type epsilonWallFunction;
value uniform 0.0153;
}

}


// ************************************************** *********************** //]

controlDict file
[CODE]
[application simpleFoam;

startFrom startTime;

startTime 0;

stopAt endTime;

endTime 100;

deltaT 0.1;

writeControl timeStep;

writeInterval 1;

purgeWrite 0;

writeFormat ascii;

writePrecision 6;

writeCompression off;

timeFormat general;

timePrecision 8;

runTimeModifiable true;
]

fvSchemes file
[CODE]
[ddtSchemes
{
default steadyState;
}

gradSchemes
{
default Gauss linear;
grad(p) Gauss linear;
grad(U) Gauss linear;
}

divSchemes
{
default none;
div(phi,U) bounded Gauss upwind;
div(phi,k) bounded Gauss upwind;
div(phi,epsilon) bounded Gauss upwind;
div(phi,R) bounded Gauss upwind;
div(R) Gauss linear;
div(phi,nuTilda) bounded Gauss upwind;
div((nuEff*dev(T(grad(U))))) Gauss linear;
}

laplacianSchemes
{
default none;
laplacian(nuEff,U) Gauss linear corrected;
laplacian((1|A(U)),p) Gauss linear corrected;
laplacian(DkEff,k) Gauss linear corrected;
laplacian(DepsilonEff,epsilon) Gauss linear corrected;
laplacian(DREff,R) Gauss linear corrected;
laplacian(DnuTildaEff,nuTilda) Gauss linear corrected;
}

interpolationSchemes
{
default linear;
interpolate(U) linear;
}
snGradSchemes
{
default corrected;
}

fluxRequired
{
default no;
p ;
}
// ***************]

fvSolutions
[CODE][solvers
{
p
{
solver PCG;
preconditioner DIC;
tolerance 1e-08;
relTol 0.01;
}

U
{
solver PBiCG;
preconditioner DILU;
tolerance 1e-08;
relTol 0.1;
}

k
{
solver PBiCG;
preconditioner DILU;
tolerance 1e-08;
relTol 0.1;
}

epsilon
{
solver PBiCG;
preconditioner DILU;
tolerance 1e-08;
relTol 0.1;
}

R
{
solver PBiCG;
preconditioner DILU;
tolerance 1e-05;
relTol 0.1;
}

nuTilda
{
solver PBiCG;
preconditioner DILU;
tolerance 1e-05;
relTol 0.1;
}
}

SIMPLE
{
nNonOrthogonalCorrectors 3;
pRefCell 0;
pRefValue 0;
residualControl
{
p 1e-2;
U 1e-3;
"(k|epsilon|omega)" 1e-3;
}
}

relaxationFactors
{
fields
{
p 0.2;
}
equations
{
U 0.2;
k 0.2;
epsilon 0.2;
R 0.2;
nuTilda 0.2;
}
}


// ************************************************** *********************** //]

Snap shots of mesh and Velocity profile is attached. When i run simulation it ran up to 5.3 after that we got floating point error (core Dumped) message.Preceding the bounding epsilon problem.
Please Help me to get this simulation.

[owayz]

Hi Sam.ho,
This post is not the solution to your problem. But an advise that might help others to help you. Always test your setup with simple model test cases before proceeding towards the solution of your actual problem. It could be easier to catch the problems in a simple test problem, where you don't have so many boundary conditions and complex setup options.
Always post the error with files "(i.e. setup (+case) or test case)" with which you encounter the problem. If you can't share the full problem make a small test case demonstrating the problem. That might help others to find the problem and help you. Or may be you will solve the problem yourself in y process to make a test case.

Best Regards,
Ali

[sam.ho]

Hi owayz,

I have simulated simple cases like flow past circular cylinder and square cylinder and i got satisfactory results.
But if i apply the similar concept here I am getting error ?

Can anybody suggest a solution ?