combustion
can anyone tell me how to give equivalence ratio value in fluent. thanks in advance
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Re: combustion
HI
Equivalence ratio value input depends on the type of combustion, one is trying to model. It offers following types of combustion models Premixed combustion Non premixed Partially premixed What type of model You are using. zenith mark |
Re: combustion
hi, i am modeling premixed combustion with an equivalence ratio of 4.4. i know the air and fuel velocity and i have given the value at the boundary condition along with the species mass fraction. then where we have to specify the equivalence value? or equivalence ratio is used to find air and fuel velocity? plz reply thanks
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Re: combustion
HI
For premixed combustion, species transport equations are not solved. Fluent solves the equation for mean progress variable'c'. Hence species in there elemental compostion remain conserved for premixed combustion. So we are left with the conservation of energy, how Fluent does it. Dear if you are using premixed combustion model then there are two possiblities 1) adiabetic In adiabetic premixed combustion, energy equation is not solved. Temperature of mixture is calculated from the temperature of inlet mixture and adiabetic flame temperature. Fluent assumes or fits a linear approximation bewteen these two temperature limits. 2) nonadiabetic in non adiabetic premixed combustion, energy equation is solved, so two informations are needed, first heat of combustion and the other is mass fraction of unburnt fuel It is the second parameter " mass fraction of unburnt fuel" in inlet stream which is calculated from equivalence ratio. Mass fraction apperas in the material properties of mixture. Defining this parameter means that you are defining the equivalence ratio. You will not see this parameter it modeling adiabetic system Hope this answers your question Zenith mark |
Re: combustion
thanks ya, i am using adiabatic condition. from ur answer i feel that i am in correct path. thanks a lot
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help
could you tell me please how to give equivalence ratio value in fluent and my type is non-premixed. thanks in advance
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