# Can I use RANS to see the effect of mixed convection?

my question is: can I use a RANS simulation to see the effect of mixed/natural convection?

Actually I have also a second question: I would like to do this in Comsol multiphysics, but it seems that it has no model that takes into account turbulence (like k epsilon, Reinolds stress, LES, ecc..). Ps: this could be because I use a pretty old version of the software, but anyway I haven't found documentation about this topic so far.

• What are your Rayleigh and Reynolds numbers? – Bill Barth Mar 16 '13 at 2:29
• I haven't set the case yet, but would be such as $\frac{Gr}{Re^2}$ would be near 1, to guarantee mixed convection. – Lorenzo Nespoli Mar 16 '13 at 7:50
• I think that you've got to know whether the flow is likely to be turbulent before you can know if RANS is applicable. – Bill Barth Mar 22 '13 at 3:56