[thegauravonline]

Dear All,

I would like to understand what is the meaning of "rhoMin" & "rho0" in the kinematic Cloud properties file in Lagrangian solver of foam-extend3.2

I want to specify and vary the density of the particles that I inject. For this, where should I make changes.

Please let me know if you are aware of this...

Also, please let me know these: "minParticleMass" & "RosinRammlerPDF"

Thank you.

[cfdopenfoam]

Hi, Gaurav.

Has your problem solved? Could you please post your answers here so that more foamers can benifit from you?

Best,

[chpjz0391]

Originally Posted by thegauravonline

Dear All,

I would like to understand what is the meaning of "rhoMin" & "rho0" in the kinematic Cloud properties file in Lagrangian solver of foam-extend3.2

I want to specify and vary the density of the particles that I inject. For this, where should I make changes.

Please let me know if you are aware of this...

Also, please let me know these: "minParticleMass" & "RosinRammlerPDF"

Thank you.

Hi Gaurav,

You may find the answer for how to inject vary density particles from this post.
http://www.cfd-online.com/Forums/ope...aticcloud.html

rhoMin means minimum density (kg/m3) I think it's for parcel.
rho0 means particle density kg/m3 (constant) for single particle
minParcelMass means minimum parcel mass kg

And one parcel could include many particles.

the parameter nParticle means the number of particles for each parcel. If you set it as 1. It will be DEM.

Kind regards,
Ping

[thegauravonline]

Originally Posted by chpjz0391

Hi Gaurav,

You may find the answer for how to inject vary density particles from this post.
http://www.cfd-online.com/Forums/ope...aticcloud.html

rhoMin means minimum density (kg/m3) I think it's for parcel.
rho0 means particle density kg/m3 (constant) for single particle
minParcelMass means minimum parcel mass kg

And one parcel could include many particles.

the parameter nParticle means the number of particles for each parcel. If you set it as 1. It will be DEM.

Kind regards,
Ping

Dear Ping,

Thank you for the reply.
But, I do not want to inject particles of varying densities, at one time, in the flow.
I would like to inject particles of uniform density once, later in the next set of simulations, I want to inject particles with different value of density but uniform for all the particles.
In this regard, I want to understand the difference between 'rho' and 'rho0' mentioned in the kinematicCloudProperties file.

Thanks

[thegauravonline]

Originally Posted by cfdopenfoam

Hi, Gaurav.

Has your problem solved? Could you please post your answers here so that more foamers can benifit from you?

Best,

Hi,

I haven't yet fully understood that.
Once, I come to know, I will let it to be known.

Thank you

[chpjz0391]

Originally Posted by thegauravonline

Dear Ping,

Thank you for the reply.
But, I do not want to inject particles of varying densities, at one time, in the flow.
I would like to inject particles of uniform density once, later in the next set of simulations, I want to inject particles with different value of density but uniform for all the particles.
In this regard, I want to understand the difference between 'rho' and 'rho0' mentioned in the kinematicCloudProperties file.

Thanks

Hi Gaurav,

Which solver are you using? DPMFoam? I have checked the kinematicCloudProperties file in DPMFoam tutorial, I did not find the parameter rho. There are only rhoMin and rho0 and I have explained that in my last post.

[thegauravonline]

Hi Peng,

I am using icoLagrangianFoam in the Lagrangian solver. There also it is mentioned rhoMin and rho0 only. I have mistakenly queried for rho.

But, Is there a limit on the value of rho0. Because, if i am changing the default value(5000) to some less values, foam is giving errors(FLOATING POINT EXCEPTION). Also, for moderate values of rho0, the solution is running only upto a limited number of time steps than that is mentioned in the controlDict file.

Could you please clarify this. Thank you.

[chpjz0391]

Originally Posted by thegauravonline

Hi Peng,

I am using icoLagrangianFoam in the Lagrangian solver. There also it is mentioned rhoMin and rho0 only. I have mistakenly queried for rho.

But, Is there a limit on the value of rho0. Because, if i am changing the default value(5000) to some less values, foam is giving errors(FLOATING POINT EXCEPTION). Also, for moderate values of rho0, the solution is running only upto a limited number of time steps than that is mentioned in the controlDict file.

Could you please clarify this. Thank you.

Hi Gaurav,
Could you post your error information (for more details) and kinematicCloudProperites file as well? And I recommend you to use a latest version.

Regards.
Ping

[thegauravonline]

Hi Ping,

The error messages are:

With "rho0-500 and rhoMin-150"
Time = 1.051

Courant Number mean: 0.156148 max: 535.037 velocity magnitude: 115.568
Evolving kinematicCloud

--> Cloud: kinematicCloud
Added 5 new parcels

Cloud: kinematicCloud
Total number of parcels added = 5255
Total mass introduced = 2.80267e-05
Current number of parcels = 4254
Current mass in system = 2.2688e-05

Cloud: kinematicCloud
Total number of parcels added = 5255
Total mass introduced = 2.80267e-05
Current number of parcels = 4254
Current mass in system = 2.2688e-05
DILUPBiCG: Solving for Ux, Initial residual = 0.990552, Final residual = 2.55921e-06, No Iterations 32
DILUPBiCG: Solving for Uy, Initial residual = 0.919057, Final residual = 5.83568e-06, No Iterations 32
DILUPBiCG: Solving for Uz, Initial residual = 0.938345, Final residual = 7.10839e-06, No Iterations 32
DICPCG: Solving for p, Initial residual = 0.682208, Final residual = 9.11394e-07, No Iterations 114
time step continuity errors : sum local = 3.32876e-07, global = 3.1143e-10, cumulative = -1.93215e-08
DICPCG: Solving for p, Initial residual = 0.978959, Final residual = 9.99862e-07, No Iterations 106
time step continuity errors : sum local = 1.0204e-05, global = 1.89962e-07, cumulative = 1.7064e-07
ExecutionTime = 159.17 s ClockTime = 159 s

Time = 1.052

Courant Number mean: 6.44676 max: 28233.3 velocity magnitude: 6098.39
Evolving kinematicCloud

--> Cloud: kinematicCloud
Added 5 new parcels

Floating point exception



With "rho0-150 and rhoMin-1.0e-15"

Time = 0.002

Courant Number mean: 0.0249048 max: 5.03595 velocity magnitude: 1.42542
Evolving kinematicCloud

--> Cloud: kinematicCloud
Added 5 new parcels

Cloud: kinematicCloud
Total number of parcels added = 10
Total mass introduced = 5.33333e-08
Current number of parcels = 10
Current mass in system = 5.33333e-08

Cloud: kinematicCloud
Total number of parcels added = 10
Total mass introduced = 5.33333e-08
Current number of parcels = 10
Current mass in system = 5.33333e-08
DILUPBiCG: Solving for Ux, Initial residual = 0.310019, Final residual = 9.42003e-06, No Iterations 8
DILUPBiCG: Solving for Uy, Initial residual = 0.356904, Final residual = 9.69334e-06, No Iterations 7
DILUPBiCG: Solving for Uz, Initial residual = 0.492843, Final residual = 3.53762e-06, No Iterations 9
DICPCG: Solving for p, Initial residual = 0.0327284, Final residual = 9.13131e-07, No Iterations 109
time step continuity errors : sum local = 8.23451e-08, global = 6.57272e-10, cumulative = 1.46996e-09
DICPCG: Solving for p, Initial residual = 0.136092, Final residual = 8.68997e-07, No Iterations 114
time step continuity errors : sum local = 8.66451e-09, global = 2.07729e-11, cumulative = 1.49073e-09
ExecutionTime = 0.47 s ClockTime = 1 s

Time = 0.003

Courant Number mean: 0.0259055 max: 5.00462 velocity magnitude: 2.06054
Evolving kinematicCloud

--> Cloud: kinematicCloud
Added 5 new parcels

Cloud: kinematicCloud
Total number of parcels added = 15
Total mass introduced = 8e-08
Current number of parcels = 13
Current mass in system = 6.93333e-08

Cloud: kinematicCloud
Total number of parcels added = 15
Total mass introduced = 8e-08
Current number of parcels = 13
Current mass in system = 6.93333e-08
Floating point exception


The kinematic cloud properties file (foam-extend 3.2) is the following:

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | foam-extend: Open Source CFD |
| \\ / O peration | Version: 3.2 |
| \\ / A nd | Web: http://www.foam-extend.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object kinematicCloud1Properties;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

active yes;

// Particle sub-models
InjectionModel ConeInjection;
DragModel SphereDrag;
DispersionModel none;
PatchInteractionModel StandardWallInteraction;
PostProcessingModel PatchPostProcessing;

// Parcel basis type
parcelBasisType mass;

constantProperties{
rhoMin rhoMin [ 1 -3 0 0 0 ] 1e-15;

// Minimum particle mass
minParticleMass minParticleMass [ 1 0 0 0 0] 1.0e-15;

// Parcel thermo properties
rho0 rho0 [ 1 -3 0 0 0] 5000;
}

// Coupling between particles and carrier phase via source terms
coupled true;

cellValueSourceCorrection on;

// Integer used to identify different parcel types
parcelTypeId 2;

interpolationSchemes
{
rho cell;
U cellPointFace;
mu cell;
}

integrationSchemes
{
U Euler;
}

particleForces
{
gravity off;
virtualMass off;
pressureGradient off;
}

ConeInjectionCoeffs
{
// type patchInjection;
// patchName in;
SOI 0;
parcelBasisType mass;
duration 7.5;
position (0 0.0024 0.0024);
direction (1 0 0);
parcelsPerSecond 5000;
volumeFlowRate constant 0.01;
Umag constant 5.0;
thetaInner constant 0.0;
thetaOuter constant 90.0;
parcelPDF
{
pdfType RosinRammler;
RosinRammlerPDF
{
minValue 50.0e-06;
maxValue 100.0e-06;
d (75.0e-06);
n (0.5);
}
}

// Total mass to inject
massTotal massTotal [ 1 0 0 0 0] 2.0e-4;
}

StandardWallInteractionCoeffs
{
type rebound;
}

PatchPostProcessingCoeffs
{
maxStoredParcels 10000;
patches (
in
out1
out2
);
}

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


Thank you

[chpjz0391]

Originally Posted by thegauravonline

Hi Ping,

The error messages are:

With "rho0-500 and rhoMin-150"
Time = 1.051

Courant Number mean: 0.156148 max: 535.037 velocity magnitude: 115.568
Evolving kinematicCloud

--> Cloud: kinematicCloud
Added 5 new parcels

Cloud: kinematicCloud
Total number of parcels added = 5255
Total mass introduced = 2.80267e-05
Current number of parcels = 4254
Current mass in system = 2.2688e-05

Cloud: kinematicCloud
Total number of parcels added = 5255
Total mass introduced = 2.80267e-05
Current number of parcels = 4254
Current mass in system = 2.2688e-05
DILUPBiCG: Solving for Ux, Initial residual = 0.990552, Final residual = 2.55921e-06, No Iterations 32
DILUPBiCG: Solving for Uy, Initial residual = 0.919057, Final residual = 5.83568e-06, No Iterations 32
DILUPBiCG: Solving for Uz, Initial residual = 0.938345, Final residual = 7.10839e-06, No Iterations 32
DICPCG: Solving for p, Initial residual = 0.682208, Final residual = 9.11394e-07, No Iterations 114
time step continuity errors : sum local = 3.32876e-07, global = 3.1143e-10, cumulative = -1.93215e-08
DICPCG: Solving for p, Initial residual = 0.978959, Final residual = 9.99862e-07, No Iterations 106
time step continuity errors : sum local = 1.0204e-05, global = 1.89962e-07, cumulative = 1.7064e-07
ExecutionTime = 159.17 s ClockTime = 159 s

Time = 1.052

Courant Number mean: 6.44676 max: 28233.3 velocity magnitude: 6098.39
Evolving kinematicCloud

--> Cloud: kinematicCloud
Added 5 new parcels

Floating point exception



With "rho0-150 and rhoMin-1.0e-15"

Time = 0.002

Courant Number mean: 0.0249048 max: 5.03595 velocity magnitude: 1.42542
Evolving kinematicCloud

--> Cloud: kinematicCloud
Added 5 new parcels

Cloud: kinematicCloud
Total number of parcels added = 10
Total mass introduced = 5.33333e-08
Current number of parcels = 10
Current mass in system = 5.33333e-08

Cloud: kinematicCloud
Total number of parcels added = 10
Total mass introduced = 5.33333e-08
Current number of parcels = 10
Current mass in system = 5.33333e-08
DILUPBiCG: Solving for Ux, Initial residual = 0.310019, Final residual = 9.42003e-06, No Iterations 8
DILUPBiCG: Solving for Uy, Initial residual = 0.356904, Final residual = 9.69334e-06, No Iterations 7
DILUPBiCG: Solving for Uz, Initial residual = 0.492843, Final residual = 3.53762e-06, No Iterations 9
DICPCG: Solving for p, Initial residual = 0.0327284, Final residual = 9.13131e-07, No Iterations 109
time step continuity errors : sum local = 8.23451e-08, global = 6.57272e-10, cumulative = 1.46996e-09
DICPCG: Solving for p, Initial residual = 0.136092, Final residual = 8.68997e-07, No Iterations 114
time step continuity errors : sum local = 8.66451e-09, global = 2.07729e-11, cumulative = 1.49073e-09
ExecutionTime = 0.47 s ClockTime = 1 s

Time = 0.003

Courant Number mean: 0.0259055 max: 5.00462 velocity magnitude: 2.06054
Evolving kinematicCloud

--> Cloud: kinematicCloud
Added 5 new parcels

Cloud: kinematicCloud
Total number of parcels added = 15
Total mass introduced = 8e-08
Current number of parcels = 13
Current mass in system = 6.93333e-08

Cloud: kinematicCloud
Total number of parcels added = 15
Total mass introduced = 8e-08
Current number of parcels = 13
Current mass in system = 6.93333e-08
Floating point exception


The kinematic cloud properties file (foam-extend 3.2) is the following:

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | foam-extend: Open Source CFD |
| \\ / O peration | Version: 3.2 |
| \\ / A nd | Web: http://www.foam-extend.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object kinematicCloud1Properties;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

active yes;

// Particle sub-models
InjectionModel ConeInjection;
DragModel SphereDrag;
DispersionModel none;
PatchInteractionModel StandardWallInteraction;
PostProcessingModel PatchPostProcessing;

// Parcel basis type
parcelBasisType mass;

constantProperties{
rhoMin rhoMin [ 1 -3 0 0 0 ] 1e-15;

// Minimum particle mass
minParticleMass minParticleMass [ 1 0 0 0 0] 1.0e-15;

// Parcel thermo properties
rho0 rho0 [ 1 -3 0 0 0] 5000;
}

// Coupling between particles and carrier phase via source terms
coupled true;

cellValueSourceCorrection on;

// Integer used to identify different parcel types
parcelTypeId 2;

interpolationSchemes
{
rho cell;
U cellPointFace;
mu cell;
}

integrationSchemes
{
U Euler;
}

particleForces
{
gravity off;
virtualMass off;
pressureGradient off;
}

ConeInjectionCoeffs
{
// type patchInjection;
// patchName in;
SOI 0;
parcelBasisType mass;
duration 7.5;
position (0 0.0024 0.0024);
direction (1 0 0);
parcelsPerSecond 5000;
volumeFlowRate constant 0.01;
Umag constant 5.0;
thetaInner constant 0.0;
thetaOuter constant 90.0;
parcelPDF
{
pdfType RosinRammler;
RosinRammlerPDF
{
minValue 50.0e-06;
maxValue 100.0e-06;
d (75.0e-06);
n (0.5);
}
}

// Total mass to inject
massTotal massTotal [ 1 0 0 0 0] 2.0e-4;
}

StandardWallInteractionCoeffs
{
type rebound;
}

PatchPostProcessingCoeffs
{
maxStoredParcels 10000;
patches (
in
out1
out2
);
}

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


Thank you

I found two questions. The first one is that your max Co number is larger than 1.Your first case is more than 500. So you should check your controlDic file, deltaT. Did you just change the particle parameter in kinematic and did not change any other BC ? Second, the error message is "floating point exception", which means an illegal mathematical operation (like division by zero) occurred during your simulation. I recommend you to check your initial boundary condition and particle properties.

Besides, the solver you use is different with mine, I am using the OF version from www.openfoam.org. But I think this is not the reason for your problem.

Good luck

[vidyadhar]

Thank you Ping.


Regards,
Vidyadhar/thegauravonline (from new CFD Online account)

[Desimuser1]

rho0 = your value (rho at time zero)
rhoMin = if varied, what is the least value that it has to maintain