calculation of laminar flame speed

[Pat]

Hello,

Im relatively new to chemical and reaction kinetics so this might be a
stupid question:

I want to calculate the laminar flame speed of methane mixture with
different contents of H2. I installed and started using Cantera (1.7)
and looked through the demos, especially the "flame" ones, but I still
have no idea how to it.
Since this is like a basic application, has someone done that before
and help or could point me in the right direction?

thanks a lot!

[Mahdi Salehi]

Hi,
You need to change the flamespeed.cpp code. All you have to do is to change your inlet condition. If you need to change the mass fractions at the inlet:

    vector_fp x;
    x.resize(nsp);
    for(int k=0;k<nsp;k++){
      if(k==gas.speciesIndex("CH4"))     {x[k]= Y_CH4_init; }
      else if(k==gas.speciesIndex("O2")) {x[k]= Y_O2_init; }
      else if(k==gas.speciesIndex("CO2")){x[k]= Y_CO2_init; }
      else if(k==gas.speciesIndex("H2O")){x[k]= Y_H2O_init; }
      else if(k==gas.speciesIndex("H2")) {x[k]= Y_H2_init; }
      else if(k==gas.speciesIndex("N2")) {x[k]= Y_N2_init; }
      else{ x[k]=0.0; }
    }
    gas.setState_TPY(temp,pressure,DATA_PTR(x));

where for example Y_H2_init is the mass fraction of H2 that you need to change.
Cheers,

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[Pat]

thanks for the reply, sounds just like what I want!
Only problem is, I cant find the flamespeed file in my demos. Is it
only included in the latest version, and does that mean I have to
build it for c++, cause so far Im using a matlab/python version
installed via msi installer....(version 1.7)

thanks

On 1 Apr., 19:46, Mahdi Salehi <smehdi...@gmail.com> wrote:
> Hi,
> You need to change the flamespeed.cpp code. All you have to do is to change
> your inlet condition. If you need to change the mass fractions at the inlet:
>
>     vector_fp x;
>     x.resize(nsp);
>     for(int k=0;k<nsp;k++){
>       if(k==gas.speciesIndex("CH4"))     {x[k]= Y_CH4_init; }
>       else if(k==gas.speciesIndex("O2")) {x[k]= Y_O2_init; }
>       else if(k==gas.speciesIndex("CO2")){x[k]= Y_CO2_init; }
>       else if(k==gas.speciesIndex("H2O")){x[k]= Y_H2O_init; }
>       else if(k==gas.speciesIndex("H2")) {x[k]= Y_H2_init; }
>       else if(k==gas.speciesIndex("N2")) {x[k]= Y_N2_init; }
>       else{ x[k]=0.0; }
>     }
>     gas.setState_TPY(temp,pressure,DATA_PTR(x));
>
> where for example Y_H2_init is the mass fraction of H2 that you need to
> change.
> Cheers,
>

[Mahdi Salehi]

I am using Version 1.8 and here is the location:
cantera-1.8/cantera-1.8/Cantera/cxx/demos/