Hi to all fluent users,

I've to define a source term, for an uds transport equation, with this expression:

S=A*exp(B-C_UDSI(c,t, 0))

(A,B: costants)

and I was wondering if this is right or if I've to use a linearized expression, since the exponential has an uds as argument??? Sorry for this stupid doubt!!!

Regards,

Giordano Bruno

Hi Giordano

When you specify the source term make sure its per unit volume so you may have to divde that soure term with the cell volume from C_VOLUME(c,t). units should be something like kg/m^3 - s

Since the source term is fairly simple you should specify the source derivatives because they will help stablise and speed up the solution.

your source term derivative should be soemthing like ds[eqn] = -A*exp(B-C_UDSI(c,t,0))

Sorry for my incomplete message, but the costant A has the correct unit [kg/m^3-s] and my doubt concerns only the correct expression to use...

Any suggestion'd be appreciated!!!

Giordano Bruno