DEFINE_SOURCE for methane injection

Vitali

yes, I use "boudary condition" and I activated "Source Terms" in GUI. Then I can see in the list all species that I use (CH4, O2, CO2 and H20), mass (kg/m3-s), axial momentum and more. After I set my DEFINE_SOURCE in UDF to the methane in the list. I use UDF, because my ijected mass of methan must be change. But my problem is it, I cann't understand, how must I calculate the value of source.

source has units [kg/(m3*s)], so I use formel

source = mass flow of Methan that I inject [kg/s] / C_VOLUME(c,t)[ m3]

But If I calculate in this way, I get to many injected methane. Dose somebody know, what is it wrong? Thanks

Vitali