i have many problem recently,about fluent's user-defined-function , for example : new subroutines are written to calculate the chemical reaction for this simulation , i used fluent's macro [DEFINE_UDS_FLUX(name ,face,thread,i)],but manual isn't explain kind of i vlave ,is zero or anynumber or anyword ~????

hi

DEFINE_UDS_FLUX (name, f, t, i)

i is integer : is the name of the UDF specified by you: i = 0 is associated with udf scalar-0

This function is for defining the convective flux in the sclaar transport equation. For most cases you won't need to change from the default method and thus you normally won't need to use it.

For chemical reactions etc., the source term udf is most likely the best way to add sources of chemical species, energy and mass to the conservation equations.

If you want more info on this routine reply.

Greg