Turbulence parameters on the free stream boundary
 

Hey!

I have an underexpanding nozzle and I set pressure outlet as a boundary condition for all the outlet boundaries around the domain. I use k-omega SST turbulence model and I am puzzled what kind of back-flow turbulence intensity and viscosity ratio should I apply on the outlet boundary. At the moment I have run with I=5% and turb. visc. ratio = 0.1 at the outlet. In the nozzle I have same intensity but greater viscosity ratio. This has worked well, but I would like to hear some other opinions that is it a right way to approach...