| farzadmech |
July 7, 2022 01:29 |
Jet simulation using pimplefoam(LES)0OF2112
1 Attachment(s)
Hello all
I am using pimpleFoam(LES) to simulate water jet. My mesh is good and it can resolve the jet, but I need to add synthetic turbulence in to nozzle jet since it is to strong and coherent without entrance turbulence. I am using OF2112, U(especially turbulentDFSEMInlet)and P boundary conditions as I put in below.
With 10% turbulence intensity, my jet is still very coherent and does not dissipate as I attached the jet figure to this thread. what should I do? Are mt Turbulence Intensity parameter defined logically?
Nozzle diameter = 0.005 m
Nozzle velocity = 0.64 m/s
Boundary conditions for Nozzle_Outlet (turbulentDFSEMInlet);
Code:
Nozzle_Outlet
{
type turbulentDFSEMInlet;
delta 0.005; // 1*0.005; //Characteristic length scale
R uniform (0.004096 0.0 0.0 0.004096 0.0 0.004096); // 10%*0.64==>0.064=======>0.064^2=0.004096
U uniform (0.0 0.64 0.0);
value uniform (0.0 0.64 0.0);
L uniform 0.001; // 0.2*0.005=0.001
nCellPerEddy 2;
}
Boundary conditions for Velocity;
Code:
/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 6
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volVectorField;
location "0";
object U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [0 1 -1 0 0 0 0];
internalField uniform (0 0 0);
boundaryField
{
TopWall
{
type inletOutlet;
inletValue uniform (0 0 0);
value uniform (0 0 0);
}
fixedWalls
{
type fixedValue;
value uniform (0 0 0);
}
Nozzle_solidBodys
{
type fixedValue;
value uniform (0 0 0);
}
Nozzle_Outlet
{
type turbulentDFSEMInlet;
delta 0.005; // 1*0.005; //Characteristic length scale
R uniform (0.004096 0.0 0.0 0.004096 0.0 0.004096); // 10%*0.64==>0.064=======>0.064^2=0.004096
U uniform (0.0 0.64 0.0);
value uniform (0.0 0.64 0.0);
L uniform 0.001; // 0.2*0.005=0.001
nCellPerEddy 2;
}
}
// ************************************************************************* //
And for pressure, we have below boundary condition;
Code:
/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 6
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
location "0";
object p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [0 2 -2 0 0 0 0];
internalField uniform 0;
boundaryField
{
TopWall
{
type fixedMean;
meanValue constant 0;
value uniform 0;
}
fixedWalls
{
type fixedFluxPressure;
gradient uniform 0;
value uniform 0;
}
Nozzle_solidBodys
{
type fixedFluxPressure;
gradient uniform 0;
value uniform 0;
}
Nozzle_Outlet
{
type zeroGradient;
}
}
// ************************************************************************* //
Thanks,
Farzad |
