correct turbulence model
I have a few questions about the correct selection of a turbulence model.
the flow is in the headspace of a tank exposed to ambient conditions. the headspace as a pressure outlet at the top. working fluid is air and since characteristic length is about 2 m, even for temperature difference of 5 K, rayleigh number goes in the transition region around 10e8 to 10e9 Is K omega model the only option for me? Can I use K epsilon for this case? Will K epsilon with RNG be a better choice? If I want to use std wall functions for K epsilon, I have to keep the cell thickness at the wall pretty high, that makes the whole grid too coarse -- so I am clueless there. If I go for K epsilon with enhanced wall, i know i need to maintain y+ around 1, but i have seen it go as high as 3. In one case, it went up to 10 -- IS that bad? will that give wrong results? Do I need to step back and rerun that time part with refined mesh? \ Please shed light on whatever questions you can. thank you, CO2 |
Re: correct turbulence model
Hi, About the enhanced wall treatment, you may need to follow the instruction given by Fluent, i.e. maintain y+ around 1. you may need to refine.
|
All times are GMT -4. The time now is 03:03. |