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-   -   FLUENT 6.3 for particle deposition studies? (http://www.cfd-online.com/Forums/fluent/50323-fluent-6-3-particle-deposition-studies.html)

Prashanth January 19, 2009 17:48

FLUENT 6.3 for particle deposition studies?
 
Hello all

I am working on CFD simulation of syngas deposition on a high pressure turbine vane. While going through literature on this topic, I found that FLUENT 4.4.7 is the best version for this study as the particle-wall interaction is more realistically modeled in this version than in FLUENT 5. FLUENT 5 uses rebounding/sticking for all particles while 4.4.7 allows the condition of the particle at the surface to be determined by user defined subroutines. I want to know if FLUENT 6.3 has the capability of 4.4.7 in this area. If not, what are my options?

Thanks,

Prashanth

Allan Walsh January 20, 2009 14:11

Re: FLUENT 6.3 for particle deposition studies?
 
Yes, you can use a user defined function to specify the fate of a particle when contacting a wall in Fluent 6.3.

We had several subroutines for this purpose which we ported directly from Fluent 4 to Fluent 6, bypassing version 5.

By the way, hopefully Fluent 12 will released in the first part of this year, which does provide some additional features.

eloy785 June 29, 2010 12:26

particles
 
hi

I'm working with fluent 6.3.26 and i want to know if i can put an specific quantity (KG) in a specific wall and then set a velocity inlet in order to carry out the particles in the wall.

regards

Jovana November 9, 2011 09:54

Quote:

Originally Posted by Allan Walsh
;156106
Yes, you can use a user defined function to specify the fate of a particle when contacting a wall in Fluent 6.3.

We had several subroutines for this purpose which we ported directly from Fluent 4 to Fluent 6, bypassing version 5.

By the way, hopefully Fluent 12 will released in the first part of this year, which does provide some additional features.

Hello, I need some info. I am new in this UDF codes, without knowledge in FORTRAN or C language. Any way, I have found a code that I can use for particle - wall Interaction USREFL.F that is used in Fluent 4. I am working in Fluent 6. How can I use this code?:confused:

Regards!:)

fariba.j April 15, 2012 15:44

deposition of particles
 
hi,
I want to model deposition of particles by thermophoretic force and brownian diffusion in laminar flow. i want to use euler-euler approach,but i dont know which of these models i must use,species model or multiphase model.also i work with fluent 6.3.26
thanks a lot

Amir April 16, 2012 03:34

Quote:

Originally Posted by fariba.j (Post 354774)
hi,
I want to model deposition of particles by thermophoretic force and brownian diffusion in laminar flow. i want to use euler-euler approach,but i dont know which of these models i must use,species model or multiphase model.also i work with fluent 6.3.26
thanks a lot

Dear Fariba,

If you want to use Eulerian approach; you can perform UDS equation as a simplified form of species transport; here, the diffusion term plays the brownian role.

Bests,

fariba.j April 18, 2012 14:40

Quote:

Originally Posted by Amir (Post 354819)
Dear Fariba,

If you want to use Eulerian approach; you can perform UDS equation as a simplified form of species transport; here, the diffusion term plays the brownian role.

Bests,

hi
thanks for your answer,i think i need udf to add thermophoresis term to uds,also uds is for single-phase
if I want to model coagulation of particles with their thermophoresis deposition,i have to use population balance,for this case,i have to add themophoresis & brownian diffusion terms to this equation with a udf,is that true??? pleas help me
thanks

Amir April 19, 2012 03:16

Quote:

Originally Posted by fariba.j (Post 355460)
hi
thanks for your answer,i think i need udf to add thermophoresis term to uds,also uds is for single-phase
if I want to model coagulation of particles with their thermophoresis deposition,i have to use population balance,for this case,i have to add themophoresis & brownian diffusion terms to this equation with a udf,is that true??? pleas help me
thanks

Dear Fariba,

Regarding thermoforetic term, you have to use a UDF but coagulation effect is a lagrangian feature and you may model it in eulerian point of view. But about brownian effect, you don't need any UDF; the diffusion term of UDS equation has required effect.

Bests,

fariba.j April 19, 2012 13:44

Quote:

Originally Posted by Amir (Post 355534)
Dear Fariba,

Regarding thermoforetic term, you have to use a UDF but coagulation effect is a lagrangian feature and you may model it in eulerian point of view. But about brownian effect, you don't need any UDF; the diffusion term of UDS equation has required effect.

Bests,

Dear Amir,
I agree with you,but I don't know, how I can perform thermophoretic with a udf to uds,through sourse term?! but source term must be constant,while my source term is a function.
also,uds is for single-phase,while I have a particle-laden flow(discrete particles in a countinous gas flow),in material panel,I have to only introduce gas(for example air) as material? I mustn't define two materil (a gas and a solid) in fluid catigory and define their properties???

cheers,

Amir April 19, 2012 15:38

Quote:

Originally Posted by fariba.j (Post 355695)
how I can perform thermophoretic with a udf to uds,through sourse term?! but source term must be constant,while my source term is a function.

The source term can be a function of other parameters! Here this a function of temperature gradient and you can perform it with a simple UDF. (refer to UDF manual)
Quote:

Originally Posted by fariba.j (Post 355695)
also,uds is for single-phase,while I have a particle-laden flow(discrete particles in a countinous gas flow),in material panel,I have to only introduce gas(for example air) as material? I mustn't define two materil (a gas and a solid) in fluid catigory and define their properties???

You have one material if you want to use eulerian approach as you said before. In this methodology, you'll obtain particle concentration (UDS; a scalar) not the particle trajectories and the only particle-related data is diffusion coefficient which provided in base material panel.

fariba.j April 20, 2012 02:13

my professor believe that for my problem, I have to spot one-phase, and calculate particle concentration with a uds,but I think I have to spot two-phase(fluid-solid) and use mixture multiphase model(i spot the same velocity for phases,so mixture model reduce to homogenous multiphase flow) and calculate particle concentration with a uds.which of us say correct?

fariba.j April 20, 2012 02:29

[QUOTE=Amir;355710]The source term can be a function of other parameters! Here this a function of temperature gradient and you can perform it with a simple UDF. (refer to UDF manual
In sorce term help,say that in sorce term panel,from drop-list you can choose none,constant or udf for defining your source term.But there aren't udf option in drop-list(only none and constant),so I don't know, how I can define a non-constant term to uds through udf!

Amir April 20, 2012 04:24

Quote:

Originally Posted by fariba.j (Post 355744)
my professor believe that for my problem, I have to spot one-phase, and calculate particle concentration with a uds,but I think I have to spot two-phase(fluid-solid) and use mixture multiphase model(i spot the same velocity for phases,so mixture model reduce to homogenous multiphase flow) and calculate particle concentration with a uds.which of us say correct?

I agree with your supervisor. Computing particle concentration doesn't need extra phase and can be easily handled via a UDS in a single phase.
Quote:

Originally Posted by fariba.j (Post 355747)
In sorce term help,say that in sorce term panel,from drop-list you can choose none,constant or udf for defining your source term.But there aren't udf option in drop-list(only none and constant),so I don't know, how I can define a non-constant term to uds through udf!

After loading a UDF for source term, you can see and choose UDF option in this panel.

Bests,

fariba.j April 21, 2012 12:46

After loading a UDF for source term, you can see and choose UDF option in this panel.

Bests,[/QUOTE]


thank you very much,for your guidance. but my continous equation doesn't converge(I specified 1e-6 for residual)

Maryam-A September 17, 2015 02:05

Hi there
I'm simulating nanofluid flow in microchannel, I want to use one transport equation for volume fraction. I wrote udf but I have problem:(
1- the error is : Label "n_uds" not found.
: function " internal_error " not found.
this is one part of my cod:
enum
{
alpha,
A,
B,
N_REQUIRED_UDS
};
DEFINE_ADJUST(alpha_adjust,d)
{
real Laplacian;
Thread *t;
cell_t c;
if(N_UDS<N_REQUIRED_UDS)
Internal_Error("not enough user-defined scalars allocated");

thread_loop_c(t,d)
{
begin_c_loop(c,t)
{
C_UDSI(c,t,1)=C_T_G(c,t)[0];
C_UDSI(c,t,2)=C_T_G(c,t)[1];
/*C_UDSI(c,t,3)=C_T_G(c,t)[2];*/
Laplacian=Laplacian+C_UDSI_G(c,t,1)[0]+C_UDSI_G(c,t,2)[1];
}
end_c_loop(c,t)
}
C_UDSI(c,t,1)=Laplacian;
}
As you see I used 3 uds, 1 for volume fraction, 2 others for calculation of temperature gradient and make Laplacian.
is it write?
2-another question is I used single phase, is it write?:confused:
I would appreciate if anyone can help me.


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