[arun1994]

Dear all,

How can we evaluate the pope criterion to check the percentage of solved vs modeled turbulence in STARCCM? I would like to evaluate the quality of the LES simulation.

Arun

[arun1994]

Any answers please?

[ping]

i have never come across this but did some reading and think there will be ways to do it but you will need to do a bit of reading etc yourself.

pope = k-sgs/(k-sgs + k-resolved) is one way of expressing it and then assessing that this is greater than about 0.8 to show that dns has been achieved in most of the les field.

subgrid scale turbulence, k-sgs, is available as a field function in star when you use the Ffowcs Williams-Hawkings Model which you probably dont need or want - see this help page: LES and Subgrid Scale Turbulence Models Reference. otherwise the formulas are all documented in the star theory and you could create you own function.

the resolved turbulence, k-resolved, could be harder since it also might not be available in the system fields when using les but you can also create fields of your own for this but with more work since you need the use field monitors to come up with rms and average velocity components then combine in the classic formula for turbulent kinetic energy.

if you do a search for pope in the main cfd forum above this one there is some good and not so good advice and links to help you with the formulas and understanding, as there is elsewhere on the net.

[arun1994]

Thank you very much for your answer