Easy question:c value at boundary
 

Hello everyone,

Shortly and to the point: I have set up a partially premixed combustion case, where a perfect mixture of fuel and air are discharged into a chamber where fresh air is passing by from further upstream.

so I have:

Air inlet ---> burners (fuel+air) --> chamber --> outlet

The trouble is that I get completely different results depending on the value of c at the air-only boundary condition. Fluent says so you can set either c=0 or c=1. Only with c = 1 the results make sense, all the fuel is nicely burnt.

Of course I set c=0 at the fuel-air inlet.

I am considering switching to non-premixed only. I think that with the partially premixed set-up, you get inconsistent results in terms of temperatures and compositions. I guess I'm misunderstanding something.

Any prior experience on how to deal or better understand what the partially premixed model does is appreciated.

Thanks in advance