[mingllove]

Problem：
Pipe flow driven by pressure input;
Governing Equations including Navier-Stokes, Possion-Nernst-Plank (transport equation);
Using UDS to code Possion-Nernst-Plank (transport equation);
The strategy is included in figure.

About the Code:
“uds-flux.c”
# include “udf.h”
# include “sg.h”
• DEFINE_UDS_FLUX(UDS0_FLUX,f,t,i){…}
• DEFINE_UDS_FLUX(UDS1_FLUX,f,t,i){…}
• DEFINE_SOURCE(POSSION_SOURCE,c,t,dS,eqn){…}
• DEFINE_UDS_UNSTEADY(uds0_unsteady,c,t,i,apu,su){…}
• DEFINE_UDS_UNSTEADY(uds0_unsteady,c,t,i,apu,su){…}
The problems are how to code the DEFINE_UDS_FLUX. Is there any example or tutorial?

Can anybody help me to define a UDF for it?
Thanks