reactingFoam-velocity calculation
 

Hi Foamers,

I'm using reactingFoam (openFoam2.1.1) for solving premixed combustion in a 2d planar channel. Actually I doubt the solution for velocity because I get different results for velocity with simulation in Fluent.
Here is the problem: When combustion happens, the temperature increases suddenly in the flame area therefore in that area the density decreases accordingly (I see this behaviours in both OpenFoam and Fluent). So for the mass flow to conserve, the velocity should increase since the cross section does not change which is the case in Fluent results (velocity in the flame area is much bigger than the inlet velocity); however in the openFoam results, I don't see that change in velocity in results. I guess there is something missing in solving momentum equation. Maybe the density is not updating in UEqn.H or different wrong is used for solving for velocity! I don't know yet :(
Does anyone have any idea?
Any hint would be greatly appreciated.

Thanks