CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   OpenFOAM (http://www.cfd-online.com/Forums/openfoam/)
-   -   Solution is NOT APPROPRIATE WHEN COMPARED TO CFX (http://www.cfd-online.com/Forums/openfoam/129995-solution-not-appropriate-when-compared-cfx.html)

adarsh tiwari February 18, 2014 00:54

Solution is NOT APPROPRIATE WHEN COMPARED TO CFX
 
Hi all,

I am trying to do some simulations in turbulent modelling using OpenFOAM and also comparing the results with CFX.

the velocity in the OF's results is nearly zero due to no pressure drop, while in CFX, i am satisfied with the velocity range of 65 m/s with some pressure drop.

The solvers I have used for trial are

1) rhoLTSPimpleFoam
2) rhoSimpleFoam
3) simpleFoam

[the 'P' file] [/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.2.2 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
object p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [1 -1 -2 0 0 0 0];

internalField uniform 0.956e5;

boundaryField
{
HOUSING
{
type zeroGradient;
}
VALVE
{
type zeroGradient;
}

INLET
{
type zeroGradient;
}
OUTLET
{
type fixedValue;
value $internalField;
}
}
]


[The T file][/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.2.2 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
object T;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 0 0 1 0 0 0];

internalField uniform 487.94;

boundaryField
{

HOUSING
{
type fixedValue;
value uniform 298;
}
VALVE
{
type fixedValue;
value uniform 298;
}
INLET
{
type fixedValue;
value uniform 487.94;
}
OUTLET
{
type zeroGradient; //inletOutlet;
// value $internalField;
// inletValue $internalField;
}
}]

[the U file] [/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.2.2 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ 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
{
HOUSING
{
type fixedValue;
value uniform (0 0 0);
}
VALVE
{
type fixedValue;
value uniform (0 0 0);
}
INLET
{
type pressureInletVelocity; //flowRateInletVelocity;
// massFlowRate constant 0.00085;
value uniform (0 0 0);
}
OUTLET
{
type flowRateInletVelocity; //inletOutlet; //fluxCorrectedVelocity;
massFlowRate constant 0.00085;
value uniform (0 0 0);
//inletValue uniform (0 0 0);
}
}

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

Except some flow pattern variations all the results are nearly same for all the solvers:D.

I have to solve it ASAP, else my instructor will kick my a$$ :D:D

Thanks in Advance,
ragards,
Adarsh Tiwari

adarsh tiwari April 2, 2014 02:29

nothing at all ....????

betakv April 2, 2014 03:59

You have mess in boundary conditions. For velocity you have to prescribe mass flow on inlet and zeroGradient/inletOutlet on outlet. For temperature is better to use adiabatic wall zeroGradient on the wall

kmooney April 2, 2014 14:45

http://www.cfd-online.com/Forums/ope...-get-help.html

adarsh tiwari April 10, 2014 02:25

Thanks betakv and kmooney,

It solved the issue.:):):)

Best Regards,
Adarsh Tiwari


All times are GMT -4. The time now is 23:52.