Hi,

I have created a geometry for a Fluid container (Fully enclosed) which is placed in a air stream, using Gambit.

In Fluent, I define BC for Fluid container as Water and set other relevant BCs.

Energy, Viscous models etc have been activated.

I run Fluent and it works.

After that I activate the model for species to change the main domain as Mixture (Air and water vapour). (In the previous case just Air)

Then, Fluid inside the container also change to mixture.

How to avoid this situation ?

(Ie to keep main stream as a mixture and fluid in the container as water (not the mixture same as main stream)

i thinnk you must define your matherials at first then in the phases panel set phases in portion to each matherial that you defined in previouse step.