Methane turbulent combustion
 

Hi,

I know that I'm not original with my subject, but reaing through all the posted messages on combusion never gave me an answer for my questions.

So, what I want to know is: How do I decide which reaction mechanism to use (one- or two-step). Is the choise connected somehow with obtained molar/mass fractions? How can I check the phisicality of the obtained solution? (I mean maybe there are some relation for combustion temperature related to the adiabatic one, except the fact that calculated temperature should be smaller then the adiabatic one?)

Best Regards,

Julie

Re: Methane turbulent combustion
 

If you look at reduced kinetic schemes for methane combustion in literature, there are still 20 - 30 radical reactions & species that are significant. So, using just one or two molecular reaction steps is a great simplification of a very complex problem. It will allow you to predict some of the flame characteristics (i.e. temperature profile) but others will be way off (i.e. CO formation).

Chosing a model depends on: what kinda burner you have, lean or rich combustion zones, flue gas recirculation (internal or external), etc. Besides choosing the kinetic model you may need to modify the kinetic constants or the mixing parameters A and B in the Magnussen model. And all that is different again if you switch from steady-state to transient calculations...

In short, it is essential that you have validation data, like species and temperature profiles to judge your results. Try to find a combsution problem in literature that is close to yours and use their data to validate the models.