[furqanrk]

Dear Adnan, While compiling this Drag, What is the error you are facing ??

[hypotalamoos]

many thanks for your answer,
but i cant find " addon-module" where u said....
can u help me where is the "addon" plz?
thanks

[hypotalamoos]

Originally Posted by furqanrk

With the reference to PBM Manual( ANSYS User Guide )...
The population balance module is loaded into ANSYS Fluent through the text user interface (TUI). The module can only be loaded when a valid ANSYS Fluent case file has been set or read. The text command to load the module is:

define → models → addon-module

A list of ANSYS Fluent add-on modules is displayed:

> /define/models/addon-module
Fluent Addon Modules:
0. None
1. MHD Model
2. Fiber Model
3. Fuel Cell and Electrolysis Model
4. SOFC Model with Unresolved Electrolyte
5. Population Balance Model
6. Adjoint Solver
7. Single-Potential Battery Model
8. Dual-Potential MSMD Battery Model
Enter Module Number: [0] 5
Select the Population Balance Model by entering the module number 5. During the loading process a scheme library containing the graphical and text user interface, and a UDF library containing a set of user defined functions are loaded into ANSYS Fluent. A message Addon Module: popbal...loaded! is displayed at the end of the loading process.
Best of Luck

many thanks for your answer,
but i cant find " addon-module" where u said....
can u help me where is the "addon" plz?
thanks

[eddy123]

Originally Posted by furqanrk

Dear Adnan, While compiling this Drag, What is the error you are facing ??

Dean Furqan I can compile this drag successfully and my simulations runs for a little time and after that it gives the divergence problems and the particles did not fluidize properly. Could you find any mistake in this drag which I have shared. I can not understand where I am wrong. Any help will be appreciated. Thanks

[yannan]

Hi Chittipo,
Now i am simulating a three-phase flow in a tank, the primary phase is oil and secondary phases are gas and water. the oil is agitated by gas. my interest is the size distribution of water drops. so is it feasible to model this using eulerian model coupled with pbm? besides, the volume fraction of water in my case is quite small, far less than 10%, so is eulerian model appropriate? if it is not, can i couple the discrete phase model with pbm?

please kindly give me some suggestions. Thank you in advance!

yannan

[furqanrk]

Originally Posted by hypotalamoos

many thanks for your answer,
but i cant find " addon-module" where u said....
can u help me where is the "addon" plz?
thanks

Ohh, just write this code to the text place.. (> /define/models/addon-module )
then automatically fluent allows you this :
Fluent Addon Modules:
0. None
1. MHD Model
2. Fiber Model
3. Fuel Cell and Electrolysis Model
4. SOFC Model with Unresolved Electrolyte
5. Population Balance Model
6. Adjoint Solver
7. Single-Potential Battery Model
8. Dual-Potential MSMD Battery Model
Enter Module Number: [0]

Then write ( 5 )
then, follow Models------> Population balance Model
see Attached picture

[furqanrk]

Originally Posted by eddy123

Dean Furqan I can compile this drag successfully and my simulations runs for a little time and after that it gives the divergence problems and the particles did not fluidize properly. Could you find any mistake in this drag which I have shared. I can not understand where I am wrong. Any help will be appreciated. Thanks

Dear Adnan, I can understand your problem. When do you use Fluent data base drag, Does simulation work ? If Yes... Then By using your UDF drag you have to minimize the time step size; like 1e-5 or 1e-4..
the second solution is that check Under Relaxation Factors ( URF ), Read previous papers who have already use this Drag and simulate it..

Good Luck

[hypotalamoos]

dear furqanrk
thanks a lot for your help....

[hypotalamoos]

Originally Posted by furqanrk

Ohh, just write this code to the text place.. (> /define/models/addon-module )
then automatically fluent allows you this :
Fluent Addon Modules:
0. None
1. MHD Model
2. Fiber Model
3. Fuel Cell and Electrolysis Model
4. SOFC Model with Unresolved Electrolyte
5. Population Balance Model
6. Adjoint Solver
7. Single-Potential Battery Model
8. Dual-Potential MSMD Battery Model
Enter Module Number: [0]

Then write ( 5 )
then, follow Models------> Population balance Model
see Attached picture

dear furqanrk
thanks a lot for your help....

[furqanrk]

Originally Posted by chittipo

I think, based on your Classes [10], 4 mm falls under which bin (class)? let us assume it is 4th bin. then in 0-9 bins, Bin-3-fraction is 1 at inlet and remaining 0. (I left working with PBM 3 years ago, there might have been number of changes in Fluent by now. please note my answer is based on my understanding of Fluent 3 years ago.)

Hi, chittipo,
Although it is our old conversation, I need your kind attention about the step of Initialize while using same PBM models. Let suppose the 4th BIN has 4mm mean inlet diameter of air. when INITIALIZE from INLET, Should I also put 1 for Bin-4-fraction place in initialize ? What is your idea ??( do you understand my question )

[mikeldaboffin]

Originally Posted by chittipo

Dear Members,

If you have any specific questions on PBM implementation please post here. I will try to answer them, as I gained some experience in it.

on
- Existing module (or)
- Implementation through UDF

Hi Chittipo,


While running my simulation using DQMOM in ANSYS 17.2, I wanted to access the values of the nodes and weights as well as the moments for post-processing using the DEFINE_EXECUTE_AT_END macro. The UDF that I wrote and intended to use shown below:
/* Header files inclusion */
#include"udf.h"/* Fluent header */
#include"sg_pb.h"
#include"sg_mphase.h"


real cell_volume, m_0,m_1, m_2, m_3, m_4, m_5, S_1, S_2, S_3, W_1, W_2, W_3, gran_temp1,gran_temp2, gran_temp3, VOF_s1, VOF_s2, VOF_s3, VOF_gas;



DEFINE_EXECUTE_AT_END(postprocessing_d32)
{

/* Local domain scalar variables declaration */
Domain *superdomain, *subdomain_gas, *subdomain_s1, *subdomain_s2, *subdomain_s3;

/* Local thread scalar variables declaration */
Thread *superthread, *subthread_gas, *subthread_s1, *subthread_s2, *subthread_s3;


/* Local cell-index scalar variables declaration */
cell_t cell;

/* Get pointer to superdomain */

superdomain = Get_Domain(1);
subdomain_gas = Get_Domain(2);
subdomain_s1 = Get_Domain(3);
subdomain_s2 = Get_Domain(4);
subdomain_s3 = Get_Domain(5);

/* Loop over all cell threads in the superdomain */
thread_loop_c(superthread, superdomain)

{
/* Get cell subthreads for each cell superthread of the superdomain */
subthread_gas = THREAD_SUB_THREAD(superthread, 0);
subthread_s1 = THREAD_SUB_THREAD(superthread, 1);
subthread_s2 = THREAD_SUB_THREAD(superthread, 2);
subthread_s3 = THREAD_SUB_THREAD(superthread, 3);


/* Loop over all cells in each cell superthread of the superdomain */
begin_c_loop(cell, superthread)

{
/* get the cell volume */
cell_volume = C_VOLUME(cell, superthread);
C_UDMI(cell, superthread, 0) = cell_volume;

/* get the granular temperature for each soild phase*/
gran_temp1 = C_GT(cell,subthread_s1);
C_UDMI(cell, superthread, 1) = gran_temp1;
gran_temp2 = C_GT(cell,subthread_s2);
C_UDMI(cell, superthread, 2) = gran_temp2;
gran_temp3 = C_GT(cell,subthread_s3);
C_UDMI(cell, superthread, 3) = gran_temp3;


/*get volume fractions of gas and solid phases */
VOF_s1 = C_VOF(cell,subthread_s1);
C_UDMI(cell, superthread, 4) = VOF_s1;
VOF_s2 = C_VOF(cell,subthread_s2);
C_UDMI(cell, superthread, 5) = VOF_s2;
VOF_s3 = C_VOF(cell,subthread_s3);
C_UDMI(cell, superthread, 6) = VOF_s3;
VOF_gas = C_VOF(cell,subthread_gas);
C_UDMI(cell, superthread, 7) = VOF_gas;


/* get the abscissas */
S_1 = C_PB_QMOMI_L(cell, subthread_s1, 0);
C_UDMI(cell, superthread, 8) = S_1;
S_2 = C_PB_QMOMI_L(cell, subthread_s2, 1);
C_UDMI(cell, superthread, 9) = S_2;
S_3 = C_PB_QMOMI_L(cell, subthread_s3, 2);
C_UDMI(cell, superthread, 10) = S_3;


/* get the weights */
W_1 = C_PB_QMOMI_W(cell, subthread_s1, 0);
C_UDMI(cell, superthread, 8) = W_1;
W_2 = C_PB_QMOMI_W(cell, subthread_s2, 1);
C_UDMI(cell, superthread, 9) = W_2;
W_3 = C_PB_QMOMI_W(cell, subthread_s3, 2);
C_UDMI(cell, superthread, 10) = W_3;


/* get the moments */
m_0 = C_PB_QMOMI(cell, superthread, 0);
C_UDMI(cell, superthread, 10) = m_0;
m_1 = C_PB_QMOMI(cell, superthread, 1);
C_UDMI(cell, superthread, 11) = m_1;
m_2 = C_PB_QMOMI(cell, superthread, 2);
C_UDMI(cell, superthread, 12) = m_2;
m_3 = C_PB_QMOMI(cell, superthread, 3);
C_UDMI(cell, superthread, 13) = m_3;
m_4 = C_PB_QMOMI(cell, superthread, 4);
C_UDMI(cell, superthread, 14) = m_4;
m_5 = C_PB_QMOMI(cell, superthread, 5);
C_UDMI(cell, superthread, 15) = m_5;



}

end_c_loop(superthread, superdomain)

}


}



The PBE macros, C_PB_QMOMI, C_PB_QMOMI_L and C_PB_QMOM_W, for accessing the moments, nodes and weights, respectively, do not seem to work when I use them in DQMOM simulations. However, with some modifications, in QMOM simulations they seem to work.

Do these macros work only for QMOM or also for DQMOM? If they work for DQMOM, what modifications do I need to make in my code to be able to retrieve these values of the variables.

[D.M]

Hello guys,
i'm trying to simulate particles behavior and their deposition in lung, for this purpose i'm using population balance model and i'm facing with some difficulties in extracting results. my geometry has a velocity inlet, pressure outlet, and lung's wall as boundary conditions. particles are considered to be water and the main phase is air and i'm using the eulerian method. in each time step a specific volume fraction of particles (water) are injected to the domain from the inlet.

one of the problems is that the fluent doesn't show the "moment 0" on the lung's wall properly (or better to say it doesn't show the number of particles deposited on the lung's wall in each time step properly).when i see the contours for "moment 0" it seems that after two time steps the particles are completely removed from the domain and new particles are injected from the inlet and the same thing happens to these new particles after another two time steps!! . i will be gratefull if some one help me with this problem.

tnx.

[chittipo]

Hi,

do you have any source terms in your PBE?

esp. negative source, such as evaporation or dissolution etc.... if so check how much is the impact of the negative source.

could it be the particles are leaving the domain? can u check total number of particles entering and leaving the domain?

[D.M]

Tnx for your reply chittipo,
I don't have any source term in my simulation and actually no phase change happens.
i checked the ''moment 0'' (number of the particles) in inlet, outlet, wall and interior of the fluid, the results were kind of vague for me!
Here are the results in 3 consecutive time steps:

Sum of Facet Values (time step = 1)
Moment-0
-------------------------------- --------------------
wall 4.0023093e+16
inlet 2.4974542e+17
int_fluid 4.6966571e+18
outlet 2.4667024e-12
---------------- --------------------
Net 4.9864256e+18
************************************************** *********
Sum of Facet Values (time step = 2)
Moment-0
-------------------------------- --------------------
wall 3.8546442e+14
inlet 1.2661484e-18
int_fluid 7.5776632e+16
outlet 19175.31
---------------- --------------------
Net 7.6162096e+16
************************************************** **********
Sum of Facet Values (time step = 3)
Moment-0
-------------------------------- --------------------
wall 4.0253734e+16
inlet 2.5404504e+17
int_fluid 4.7654711e+18
outlet 4917065.6
---------------- --------------------
Net 5.0597699e+18

tnx for your help.

[sina_mech]

Hi!

I'm using PBM (discrete model) for a sedimentation problem. I have a particle size distribution (5 different diameters), and the "phenomena" is set off, having no aggregation or breakage. The problem is I noticed that after few hundred seconds of simulation, the Sauter mean diameter (SMD) is almost constant everywhere in the flow (equal to the one of inlet), which doesn't make sense for me. The SMD should be higher near the bottom of the tank, I assume. Is there something that I'm missing in my simulation?
PS: gravity is on, and the same problem with Discrete phase model (DPM) instead of PBM works just fine.

[chittipo]

Hi,

it appears that "all the secondary phase" has the same momentum field and therefore same phase velocities.

do you have a possibility to use inhomogeneous method where each particle class moves with its own velocity field. I think, in this case u may say what u are expecting.

[sina_mech]

Originally Posted by chittipo

Hi,

it appears that "all the secondary phase" has the same momentum field and therefore same phase velocities.

do you have a possibility to use inhomogeneous method where each particle class moves with its own velocity field. I think, in this case u may say what u are expecting.

Thanks for the reply. I thought I will need 3 phases for inhomogeneous one. but I just have 2phases.
Does either one of SMM or QMOM use different moment fields, and result in settlement of heavier particles?

[sina_mech]

I have variable flow rate, and of course variable MOMENTs in QMOM model. Which function should I use to define the moments at the inlet?

I tried using the same function I use for velocity_inlet, but it doesn't work!

[masoud.ravan]

Hi my friends,

First of all, I wanna thank @chittipo for creating this Thread and let the members sharing their helpful experiences about PBM.
I am new to this issue, I'd be happy if anyone helps me how to start PBM, I want a comprehensive reference, book etc for ascertaining "WHAT IS PBM?"...

Thanks in Advance,

[furqanrk]

Originally Posted by masoud.ravan

Hi my friends,

First of all, I wanna thank @chittipo for creating this Thread and let the members sharing their helpful experiences about PBM.
I am new to this issue, I'd be happy if anyone helps me how to start PBM, I want a comprehensive reference, book etc for ascertaining "WHAT IS PBM?"...

Thanks in Advance,

Have you implemented PBM model with command
> /define/models/addon-module ?
If Yes... There is manual in fluent, very easy and useful !

Good Luck