[khaledhmz]

hello,I would like to conduct a simulation of premixed flame( reaction of propane-Air) with EGR...
my question is: how can i have EGR as addition in the premixed tube(i want to mixing the EGR with mixture(c3h8+Air)) by using fluent??because when i try to do this I received a lot of difficulties with boundary conditions ...
plz some one help me?

[LuckyTran]

Originally Posted by khaledhmz

hello,I would like to conduct a simulation of premixed flame( reaction of propane-Air) with EGR...
my question is: how can i have EGR as addition in the premixed tube(i want to mixing the EGR with mixture(c3h8+Air)) by using fluent??because when i try to do this I received a lot of difficulties with boundary conditions ...
plz some one help me?

You're mixing two/three mixtures... This is no longer a premixed flame. A premixed flame is described as a homogeneous mixture of reactants that magically (via combustion) get converted into products. There is no mixing of EGR with propane with air in a premixed combustion model. You need to check out the partially premixed or non-premixed combustion models.


If the EGR gases are completely pre-mixed with the c4h4+air (premixed means it enters the domain/BC as an already mixed mixture), only then can you use a premixed model.

[khaledhmz]

Originally Posted by LuckyTran

You're mixing two/three mixtures... This is no longer a premixed flame. A premixed flame is described as a homogeneous mixture of reactants that magically (via combustion) get converted into products. There is no mixing of EGR with propane with air in a premixed combustion model. You need to check out the partially premixed or non-premixed combustion models.


If the EGR gases are completely pre-mixed with the c4h4+air (premixed means it enters the domain/BC as an already mixed mixture), only then can you use a premixed model.

hello Lucky Tran,
thank you for reply to me,and i conduct a simulation of premixed flame (C3H8+Air) but i want to show the EGR effect in flame stabilisation,so I can add EGR in the combustor..
but the problem that I don't how to do this in fluent (like add the EGR tempreture and CO2 OR H2O mass fraction...)

[LuckyTran]

You say you want a premixed flame... Okay...

Then you need to premix it yourself before you do anything in Fluent.

Your new mixture is now c3h8 + air + egr gas altogether. Before mixing they'll each have their own temperature and pressure but after mixing they'll be at a single temperature and pressure. Figure out how to do this. This is not a Fluent problem but you can use Fluent to figure out how to mix these streams together if you like.

[khaledhmz]

yes I want to know how to do that...
can you help me?

[LuckyTran]

Originally Posted by khaledhmz

yes I want to know how to do that...
can you help me?

There's lots of ways to model this.. Do you consider the reactions frozen? Then you just take the EGR composition, add it to the c3h8 and air.


Or Do you you take chemical equilibrium? Etc etc. Up to you.

[khaledhmz]

hi,I take chemical equilibrium...