Actually they are; however, ozone is significantly denser, and tends to segregate without proper agitation.
The concentration of ozone in the ozone-air mixture is also paramount in my simulation.
I could not figure out a way to specify the appropriate the boundary conditions for the respective phases without using a multiphase model. Would the single phase model together with the species transport model (without reactions) work in this case? Either way, the age of gas UDF, appears to require some modification to account for multiple components.