 |
 |
 |
|
|
|
[Sponsors] | ||||
No pressure drop in twoPhaseEulerFoam pipe with cyclic boundaries |
 |
|
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
March 30, 2016, 06:44
|
No pressure drop in twoPhaseEulerFoam pipe with cyclic boundaries
|
#1 |
|
Senior Member
Ruben Di Battista
Join Date: May 2013
Location: Paris
Posts: 137
Rep Power: 13  |
Hello,
it's been a while I've been struggling with this without understanding why I'm getting this behaviour. I'm trying to simulate a two-phase flow with solid particles inside a liquid carrier and, even if the velocity profiles for both phases are developed, no pressure drop is achieved in the pipe. constant/polyMesh/boundary Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 3.0.1 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class polyBoundaryMesh;
location "constant/polyMesh";
object boundary;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
3
(
outlet
{
type cyclic;
inGroups 1(cyclic);
nFaces 4500;
startFace 667500;
matchTolerance 0.0001;
transform unknown;
neighbourPatch inlet;
}
inlet
{
type cyclic;
inGroups 1(cyclic);
nFaces 4500;
startFace 672000;
matchTolerance 0.0001;
transform unknown;
neighbourPatch outlet;
}
walls
{
type wall;
inGroups 1(wall);
nFaces 6000;
startFace 676500;
}
)
// ************************************************************************* //
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 3.0.1 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "constant";
object fvOptions;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
momentumSource
{
type meanVelocityForce;
active yes;
meanVelocityForceCoeffs
{
selectionMode all;
fieldNames (U.SLN2);
Ubar (0 1.3 0);
}
}
momentumSource1
{
type meanVelocityForce;
active yes;
meanVelocityForceCoeffs
{
selectionMode all;
fieldNames (U.LN2);
Ubar (0 1.3 0);
}
}
// ************************************************************************* //
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 3.0.0 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "constant";
object phaseProperties;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
phases (SLN2 LN2);
SLN2
{
diameterModel constant;
constantCoeffs
{
d 1.3e-3;
}
residualAlpha 1e-6;
}
LN2
{
diameterModel constant;
constantCoeffs
{
d 1;
}
residualAlpha 1e-6;
}
blending
{
default
{
type none;
continuousPhase LN2;
}
}
sigma
(
(SLN2 and LN2) 0
);
aspectRatio
(
);
drag
(
(SLN2 in LN2)
{
type SchillerNaumann;
residualAlpha 1e-6;
residualRe 1e-3;
swarmCorrection
{
type none;
}
}
(LN2 in SLN2)
{
type SchillerNaumann;
residualAlpha 1e-6;
residualRe 1e-3;
swarmCorrection
{
type none;
}
}
);
virtualMass
(
(SLN2 in SLN2)
{
type constantCoefficient;
Cvm 0.5;
}
(LN2 in SLN2)
{
type constantCoefficient;
Cvm 0.5;
}
);
heatTransfer
(
(SLN2 in LN2)
{
type RanzMarshall;
residualAlpha 1e-4;
}
(LN2 in SLN2)
{
type RanzMarshall;
residualAlpha 1e-4;
}
);
lift
(
);
wallLubrication
(
);
turbulentDispersion
(
);
// Minimum allowable pressure
pMin 10000;
// ************************************************************************* //
termophysicalProperties.LN2 Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 3.0.1 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "constant";
object thermophysicalProperties.LN2;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
thermoType
{
type heRhoThermo;
mixture pureMixture;
transport const;
thermo hConst;
equationOfState perfectFluid;
specie specie;
energy sensibleInternalEnergy;
}
mixture
{
specie
{
nMoles 1;
molWeight 14;
}
equationOfState
{
R 3000;
rho0 867.86;
}
thermodynamics
{
Cp 2000;
Hf 25560;
}
transport
{
mu 294.92e-6;
Pr 2.7975;
}
}
// ************************************************************************* //
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 3.0.1 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "constant";
object thermophysicalProperties.SLN2;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
thermoType
{
type heRhoThermo;
mixture pureMixture;
transport const;
thermo hConst;
equationOfState rhoConst;
specie specie;
energy sensibleInternalEnergy;
}
mixture
{
specie
{
nMoles 1;
molWeight 14;
}
equationOfState
{
rho 1026.5;
}
thermodynamics
{
Cp 1660;
Hf 25560;
}
transport
{
mu 294.92e-6;
Pr 2.42;
}
}
// ************************************************************************* //
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 3.0.1 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
location "0";
object alpha.SLN2;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [0 0 0 0 0 0 0];
internalField uniform 0.13;
boundaryField
{
outlet
{
type cyclic;
}
inlet
{
type cyclic;
}
walls
{
type zeroGradient;
}
}
// ************************************************************************* //
|
|
|
|
|
|
April 8, 2016, 11:45
|
|
#2 |
|
Senior Member
Ruben Di Battista
Join Date: May 2013
Location: Paris
Posts: 137
Rep Power: 13 |
I would like to answer to my own question. This is normal since using periodic BCs you do not have any pressure drop in the fields.
Using fvOptions > meanVelocityForce momentum source it prints in the output the pressure drop it's applying so that would be the pressure drop to apply to achieve the developed flow that we achieve during the cyclic bcs simulation. |
|
|
|
|
|
|
December 19, 2016, 03:32
|
|
#3 |
|
New Member
Bryant
Join Date: Mar 2015
Posts: 7
Rep Power: 11 |
Hi Ruben,
Thanks for your helpful information! I am facing a similar problem when setting a cyclic boundary using reactingTwoPhaseEulerFoam (I guess it is similar to twoPhaseEulerFoam without considering energy and phase change) of OF-4.1. I want to simulate a simple granular flow down inclined planes (2D situation), where the bottom patch is a noslip wall, the top is an atmosphere, and the left and right patch is set as "cyclic". But it is so weird that the mass of granular is decreasing continuingly just like the granular flows away through the cyclic boundaries. Any opinion and suggestions will be helpful to me, thanks! constant/polyMesh/boundary Code:
(
outlet
{
type patch;
nFaces 50;
startFace 4900;
}
wall_bottom
{
type wall;
inGroups 1(wall);
nFaces 50;
startFace 4950;
}
wall_left
{
type cyclic;
inGroups 1(cyclic);
nFaces 50;
startFace 5000;
matchTolerance 0.0001;
transform unknown;
neighbourPatch wall_right;
}
wall_right
{
type cyclic;
inGroups 1(cyclic);
nFaces 50;
startFace 5050;
matchTolerance 0.0001;
transform unknown;
neighbourPatch wall_left;
}
frontAndBack2
{
type empty;
inGroups 1(empty);
nFaces 5000;
startFace 5100;
}
)
0/p_rgh Code:
dimensions [1 -1 -2 0 0 0 0];
internalField uniform 1e5;
boundaryField
{
outlet
{
type prghTotalPressure;
p0 $internalField;
U U.gas;
phi phi.gas;
rho thermo:rho.gas;
value $internalField;
}
wall_bottom
{
type fixedFluxPressure;
value $internalField;
}
wall_left
{
type cyclic;
}
wall_right
{
type cyclic;
}
"frontAndBack.*"
{
type empty;
}
}
0/U.solids Code:
dimensions [0 1 -1 0 0 0 0];
internalField uniform (0 0 0);
boundaryField
{
outlet
{
type fixedValue;
value uniform (0 0 0);
}
wall_bottom
{
type fixedValue;
value uniform (0 0 0);
}
wall_left
{
type cyclic;
}
wall_right
{
type cyclic;
}
"frontAndBack.*"
{
type empty;
}
}
|
|
|
|
|
|
|
December 23, 2016, 09:27
|
|
#4 | |
|
Senior Member
Ruben Di Battista
Join Date: May 2013
Location: Paris
Posts: 137
Rep Power: 13 |
Quote:
|
||
|
|
|
||
|
December 25, 2016, 11:29
|
|
#5 |
|
New Member
Bryant
Join Date: Mar 2015
Posts: 7
Rep Power: 11 |
Hi,Ruben, thanks for your reply. I try to follow your suggestion and use inlet/outlet configuration, while another problem occurs. Now the top and bottom patch are both noslip walls and the left patch is inlet with a constant velocity 0.2m/s, the right patch is outlet with constant pressure P. However, when the granular flow approaches to the outlet, the run crashes. I guess some BC conditions I used maybe have some problems. Looking forward to any advice, thanks!
0/p_rgh Code:
dimensions [1 -1 -2 0 0 0 0];
internalField uniform 1e5;
boundaryField
{
inlet
{
type fixedFluxPressure;
value $internalField;
outlet
{
type prghPressure;
p $internalField;
value $internalField;
}
wall
{
type fixedFluxPressure;
value $internalField;
}
"frontAndBack.*"
{
type empty;
}
}
0/U.solids Code:
dimensions [0 1 -1 0 0 0 0];
internalField uniform (0 0 0);
boundaryField
{
inlet
{
type fixedValue;
value uniform (0.2 0 0);
}
outlet
{
type pressureInletOutletVelocity;
phi phi.solids;
value $internalField;
}
wall
{
type fixedValue;
value uniform (0 0 0);
}
"frontAndBack.*"
{
type empty;
}
}
0/alpha.solids Code:
dimensions [0 0 0 0 0 0 0];
internalField uniform 0;
boundaryField
{
inlet
{
type fixedValue;
value uniform 0.6;
}
outlet
{
type zeroGradient;
}
wall
{
type zeroGradient;
}
"frontAndBack.*"
{
type empty;
}
}
|
|
|
|
|
|
|
| Tags |
| pipe flow, two fluid model, two phase flow, twophaseeulerfoam |
|
|
Similar Threads
|
||||
| Thread | Thread Starter | Forum | Replies | Last Post |
| Orifice-Pipe Problem | CFXMUFFIN | CFX | 3 | July 16, 2015 19:57 |
| pressure drop - pipe flow | C.C | Main CFD Forum | 6 | November 19, 2012 11:02 |
| Unsteady pressure differential between inlet and outlet of the pipe for single phase | joshi20h | FLUENT | 0 | September 26, 2012 13:41 |
| Terrible Mistake In Fluid Dynamics History | Abhi | Main CFD Forum | 12 | July 8, 2002 10:11 |
| Hydrostatic pressure in 2-phase flow modeling (long) | DS & HB | Main CFD Forum | 0 | January 8, 2000 16:00 |
Linear Mode
