modeling multicomponent flow
 

Hi all,
I just wanted to know how to model multicomponent flow in ansys cfx. I've been running a simulation consisting of H2, N2, O2 & H2O as ideal gases, but somehow in cfx solve, it runs as a multiphase simulation. Is there a specific setting to model multicomponent flow rather than multiphase flow? Also, why is it considering this above gas mixture as multiphase flow? Any help will be gladly appreciated.
Thanks.

chk this:

http://www.kxcad.net/ansys/ANSYS_CFX.../i1298772.html

Also ensure that you have set the interaction between phases to none.