DEFINE_SOURCE, injection in one Cell, mass balance

Vitali

Hi everybody! I do some injection of methane in one Cell in zone. But if I calculate mass balance after, I see, that it was more injected in Cell. Is somebody know, what I do wrong?

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 injected mass of methan must be change and so I can quick change the location of injection's point and I don't need create a new zone.

I inject only in one Cell, which I marked with UDM equal 1. Then I can proof in looping, is it my cell for injection or not. I tried it with steady and unsteady problem, and got the same result. It was injected to many methane.

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]

the part of my C-code:

DEFINE_SOURCE(injection_in_Cell, c, t, dS, eqn) { float source=0., mass_flow=0.001; /* kg/s */ if (C_UDMI(c,t,UDM_SOURCE) ==1.0) { Message("######## Injection in Cell ID=%i\n",c); source=mass_flow / C_VOLUME(c,t); dS[eqn]=0.0; } return source; }

for test mass balance I use: /report species-mass-flow

Vitali