[Sermengi]

Hi Tobi,

thanks for your effort about the flamelet model. We are trying to simulate the Sandia D flame using the flamelet model. Now we are creating the adiabatic flamelet tables using the libOpenSMOKE. We modified the Data.inp according to the properties of the Sandia flame D. Also we use GRI Mech 3.0 for the chemical kinetics. We didn't change the operations.inp file. I am adding content of these files to my massage.

According to our input file, we found that flamelets are quenched when scalar dissipation rate is equal to 572 Hz. On the other hand, flamelets are quenched for scalar dissipation rate is equal to 433 Hz in the tables located in tutorial case of another program. There is a huge difference between the scalar dissipation rates and we can not figure out where the mistake is. We will be so happy if you give us a hint about this situation. Thanks four your help.

Best regards,
Serkan.

[wenxu]

I think the different scalar dissipation rate lead to quench means that the flame quenched at the different scalar dissipation rate values but not means that flame START to quenched!!! For 572 Hz, you may find that 550 may be quenched also.

I think FlameMaster will be a good tool to generate flamelet library. There you will find if 573HZ quenched but 572HZ not quenched, then it will calculate the flamelet equation with scalar dissipation rate between 573--572HZ.

regards,
wenxu

[Tobi]

Dear all,

I am working to reorganize the flameletModel (libOpenSMOKE) and implement LES as soon as possible. Also I realized, that no gravity term was included in momentum or pressure equation which could lead to the problem of to high velocity prediction at the centerlines compared to my validations.

[Tobi]

Originally Posted by Sermengi

Hi Tobi,

thanks for your effort about the flamelet model. We are trying to simulate the Sandia D flame using the flamelet model. Now we are creating the adiabatic flamelet tables using the libOpenSMOKE. We modified the Data.inp according to the properties of the Sandia flame D. Also we use GRI Mech 3.0 for the chemical kinetics. We didn't change the operations.inp file. I am adding content of these files to my massage.

According to our input file, we found that flamelets are quenched when scalar dissipation rate is equal to 572 Hz. On the other hand, flamelets are quenched for scalar dissipation rate is equal to 433 Hz in the tables located in tutorial case of another program. There is a huge difference between the scalar dissipation rates and we can not figure out where the mistake is. We will be so happy if you give us a hint about this situation. Thanks four your help.

Best regards,
Serkan.

Hi,

this is old topic -> http://sourceforge.net/projects/open...5.pdf/download
What I ment is that this is already done and should be work properly.
But notice that I found a bug (no gravity is included - I am so stupid that I did not found this the last years )

[Sermengi]

Thanks for your quick replies and suggestions, we will discuss the results again.

Best regards,
Serkan.

[babakflame]

Greetings Tobi

Thanks for sending me your comparison file.

That was a very nice and yet brief work describing flamelet solvers procedure.

Just one point: The LES solver which I made based on your hints and helps exits, there is just a requirement for working on PISO algorithm to be developed to PIMPLE.

I can send you my final version. So it can be tested by you and others interested.


Best,
Bobi

[Tobi]

Yes please send it to me!
Yesterday I started to develop the libOpenSMOKE tool with FOAM classes in a more readability way.
I think it could be a very nice library which could be included in the standard OpenFOAM (after I finished it).

Looking forward to finish it.

[wenxu]

Anyone on this thread is familiar with FlameMaster? I can not get converged results if fuel is diluted. The fuel side boundary condition is as follows:

Fuel Side {
dirichlet {
t = 300.0
y->N2 = 0.5825
y->CH4 = 0.0446
y->CO = 0.348
y->C2H2 = 0.0249
}
}


Could anyone give me some hints? Thank you in advance.

regards,
wenxu

[Tobi]

Dear Wenxu,

this thread is about libOpenSMOKE not Flame-Master.
Please do not mix it up. The thread should be straight-forward to that topic.

If you have questions with Flame-Master, you should open a new thread.

PS: I used it once but I am not familiar with Flame-Master.

[wenxu]

sorry for that.

[Stefano Puggelli]

Hi everybody,
I am a PhD student from University of Florence and I am now beginnig to work on combustion modeling in OpenFOAM. My first goal would be to create and validate an FGM model in FOAM for partially premixed combustion.
First of all I made a review of the model already implemented in OF (xiFoam, reactingFoam, fireFoam..) and then I am now trying to understand exactly the available flamelet model as the one built by Tobias or the one realized by Hagen Muller.
I am writing here since I would like to know if someone can give me more informations about the capabilities of these model in order to start my development program. I understand the theory behind for example the flameletSimpleFoam of flameletFoam solver, but I would like to know if you can give more informations on that models (validations, bugs, LES application test cases) considering also the FGM application
I am very interested obviously about the flamelets models but also on fireFoam model. On this second one I don't understand exactly the coupling between a mixture fraction transport equation and FSD model.. it would be great if I clear me these aspects!
Anyway I am completely willing for working together on this items!

[babakflame]

Greetings Stefano

There is an available FGM model in O.F. written by Hans Kruger. refer to:
http://www.cfd-online.com/Forums/ope...?highlight=FGM

About fireFoam:
AFA I know based on O.F. 2.2.x (I have not tested OF 2.3.x), FSD model has some deficiencies featuring:

• It only includes single step reaction
• For incorporating fuels other than propane and methane you have to find the coefficients required (not easy to find)
• If your fuel stream is a hybrid one, the model does not support it

For understanding better the implementation of FSD model refer to:



http://www.tandfonline.com/doi/abs/1...1/009#abstract

Best

[Stefano Puggelli]

Hi,
thank you for the link and for the material. During this evening and in the next days I will have a look to the FGM model.
If I find somenthing interesting I will write here!
Thank you!

[sino75]

Hi Tobi,

I am trying to simulate a Bluff-body flame (Sandia) with the flameletModel (Holzmann) for my Master thesis. First, i wanted to do a mesh study. I proceeded as following:
- cold flow
- Enthalpy defect is 0
- high dissipation rate
When I want to create a pdf library for the solver, I get following error in my log-file:
Maximum number of iteration for calculating temperature from enthalpy...
So can you please tell me how to solve this problem?

Thanks

[Tobi]

Originally Posted by sino75

Hi Tobi,

I am trying to simulate a Bluff-body flame (Sandia) with the flameletModel (Holzmann) for my Master thesis. First, i wanted to do a mesh study. I proceeded as following:
- cold flow
- Enthalpy defect is 0
- high dissipation rate
When I want to create a pdf library for the solver, I get following error in my log-file:
Maximum number of iteration for calculating temperature from enthalpy...
So can you please tell me how to solve this problem?

Thanks

You get the error with which solver?
Otherwise if it is from binary flamelet generator you make something wrong

[sino75]

Hi Tobi,

there was a mistake with my dissipation, now I solved it.

[Stefano Puggelli]

Hi Tobi,
did you ever try to test the libOpenSmoke code for premixed or partially premixed combustion? I know that the release is for non premixed combustion but maybe someone has modified it also to simulate premixed phenomena.

[Tobi]

Dear Stefano,

I never coupled that tool with premixed combustion. I think therefore you also have to take into account ignition which is not implemented. Flamelet model in that kind means mixed equal burned.

[Stefano Puggelli]

hi Tobi,
thanks for your reply! OK, I will see if the libOpensmoke could be a good starting point also for premixed combustion.
Stefano

[sino75]

Hi,

I used flameletSimpleFoam at different grids. I'm really confused because I get a relatively stabilized flame with a grid of 6000 cells and 44000 cells, but when I use the same settings with a 16000cell-grid, no chance. I tried a lot of things like relaxation factors, maxCourant number or changed the schemes, but I had no success. Courant number doesn't seem to have influence at all. Residuals are relatively high.
Did you get such a problem and could you please help? I have attached link to my case:

https://www.dropbox.com/s/nxq2xzvmbf...se.tar.gz?dl=0

Thanks in regard.