UDF defined mass flux

amu

I tried to simulate the mass transfer distribution from a to surface where there is a mass flux of 2.4e-13 kg/s. The bulk flows at 0.0001 m/s. I used UDF defined flux as shown below: #include "udf.h"

DEFINE_PROFILE(mass_flux,t,i) { face_t f;

begin_f_loop(f,t)

{

F_FLUX(f,t)=2.4e-13;

} end_f_loop(f,t)

}

However, the results are not reasonable since at such low velocity and low surface rate at steady flow, the mass distribution should not show such gradient. I checked the sets and parameters, and I cannot find why it causes. Can anybody please tell me what's wrong at the UDF defined flux?