urgent!!! please...about Premixed Combustion

mesinUGM · October 20, 2009, 06:42

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) -----à 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 30, 2012, 00:36

Quote:

Originally Posted by mesinUGM

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) -----à 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, 01:04

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, 01:19

Quote:

Originally Posted by tirtha

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, 10:22

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.

October 20, 2009, 06:42	urgent!!! please...about Premixed Combustion	#1
mesinUGM New Member Kharisma San Join Date: Oct 2009 Posts: 3 Rep Power: 17	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...

October 26, 2009, 08:07		#2
t.krishnamohan Member Krishna Join Date: Oct 2009 Posts: 34 Rep Power: 17	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. ashishvshelke likes this.

March 30, 2012, 01:04	About spark igintiion	#5
tirtha New Member tirtha Join Date: Mar 2011 Posts: 11 Rep Power: 15	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.

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October 30, 2009, 05:03		#3
mesinUGM New Member Kharisma San Join Date: Oct 2009 Posts: 3 Rep Power: 17	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) -----à 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...

March 30, 2012, 10:22		#7
tirtha New Member tirtha Join Date: Mar 2011 Posts: 11 Rep Power: 15	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.