Sage - Reaction Multiplier
 

When adjusting the reaction multiplier one of the output files writes a line stating that the reaction multiplier is not one and all reaction EXCEPT those involving nitrogen will be adjusted accordingly...why is nitrogen an exception to this?


Also, anytime I mention adjusting the reaction rate people tend to wince and disapprove...is there a specific reason some are opposed to using this?

Hi, this is because we do not want NOx chemistry in the mechanism to be affected by this tuning.

About reaction multiplier, it is something lack of clear physical justification. I think that's why people don't like it in general. I also consider it as the last option. Because it may cover some other more important issues, such as mesh resolution, numerical scheme, turbulence model, combustion model, and so on. You'd better work on those factors first before tuning the multiplier.

I hope it helps.