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-   -   urgent!!! please...about Premixed Combustion (http://www.cfd-online.com/Forums/fluent/69339-urgent-please-about-premixed-combustion.html)

mesinUGM October 20, 2009 05:42

urgent!!! please...about Premixed Combustion
 
hei guys...
i still confuse about premixed combustion model in fluent because i didn't have any tutorial about it...
i confused about mixture material...
how 2 to mix it??
if in non-premixed we used the Pre PDF...
what should i use in premixed combustion model???
and if among of you have the tutorial, please share to me...
send to my email...
(kharismasan@yahoo.com)
thx before..
respond please...

t.krishnamohan October 26, 2009 08:07

In premixed combustion, fuel and air are mixed to the molecular level. The reaction or flame is defined by a variable called progress variable. The value of the progress variable will define the reaction like for example when it is zero it means no reaction occured and if it is one complete reaction occured.

mesinUGM October 30, 2009 05:03

Ok!!! Thank you so much krishna...
But in my project i used 70%butane n 30%propane with stoichiometric formula
(0,3 C3H8 + 0,7 C4H10) + 6,05 (O2 + 3,76N2) ----- 3,7 CO2 + 4,7 H2O + 22, 748 N2
How to define the mixture material in fluent??
Can i define it if i used premixed combustion model??
If u ever tried about premixed combustion model, would u like to share it to me??
Because i need example or tutorial about it to do n compare with my project...
How??
N my project is about internal combustion/explosion in closed space without inlet and outlet..
Can i simulate it with CFD fluent??

n how ro use the spark ignition model??

Thanks awfully...

tsram90 March 29, 2012 23:36

Quote:

Originally Posted by mesinUGM (Post 234604)
Ok!!! Thank you so much krishna...
But in my project i used 70%butane n 30%propane with stoichiometric formula
(0,3 C3H8 + 0,7 C4H10) + 6,05 (O2 + 3,76N2) ----- 3,7 CO2 + 4,7 H2O + 22, 748 N2
How to define the mixture material in fluent??
Can i define it if i used premixed combustion model??
If u ever tried about premixed combustion model, would u like to share it to me??
Because i need example or tutorial about it to do n compare with my project...
How??
N my project is about internal combustion/explosion in closed space without inlet and outlet..
Can i simulate it with CFD fluent??

n how ro use the spark ignition model??

Thanks awfully...

I am trying teh combustion of Hydrogen in a closed space without any inlets or exhaust. I have done a dynamic meshing and also injection but I cannot get the combustion. I have similar doubts that you had. Can you provide some tutorials or files you used . If you have mesh and case files of your work please share it.
id is sankarram90@gmail.com

Thanks a lot in advance

tirtha March 30, 2012 00:04

About spark igintiion
 
I suppose you can use PATCH to create a high temperature zone in your geometry for ignition purpose and try if it works. About tutorials i guess you use the reference tutorial from fluent and try to use.

tsram90 March 30, 2012 00:19

Quote:

Originally Posted by tirtha (Post 352254)
I suppose you can use PATCH to create a high temperature zone in your geometry for ignition purpose and try if it works. About tutorials i guess you use the reference tutorial from fluent and try to use.


I havn't tried patch option.. and I basically don't know anything about it.. Can you please explain something about it, How to do it etc?

tirtha March 30, 2012 09:22

I have not used fluent for long time now, but you have to select a location(cells) in the geometry where you want to patch. This can be done in the MENU-ADAPT-REGION panel. There you have to give the dimensions of the location you want to patch. The do go SOLVE- INITIALIZE-PATCH and give the conditions for temperature. Which version of Fluent are you using ?

There you can give the conditions. Its like selecting a zone near the inlet, just as igniter where you will assign a high temperature. Try to find some tutorials how to patch. Patching can be done in fluent itself. In the fluent user manual also some idea about patching is there. For patching a zone you dont need any UDF in my knowledge. So try it and let me know

Tirtha.


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