Species mass fraction
 

Hello,
I am new user of Fluent and have one basic questions on using F_Y(c,t,i).

I solve a mass species equation for a aqueous mixture of N2 and O2, Now, I would like to calculate difference of their ionic concentration, I am wondering that if it is possible to use F_y(c,t,1)-F_y(c,t,0)?! How I can find out that what the i for O2 and N2 is?! For example, if i=1 denotes o2 or n2?!

If there is any easier way to calculate difference of ionic concentrations of O2 and N2 in the UDF?!

Thank you in advance!

The species are numbered according to their order in the Fluent panel (if O2 is first, i=0). Also, you probably want to use C_YI(c, t, 0) and C_YI(c,t,1). This will give you the cell concentration, not F_YI (f,t,i), which is the face concentration.

ComputerGuy