CFD Online Logo CFD Online URL
Home > Forums > FLUENT

correct turbulence model

Register Blogs Members List Search Today's Posts Mark Forums Read

LinkBack Thread Tools Display Modes
Old   May 7, 2004, 11:05
Default correct turbulence model
Posts: n/a
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
  Reply With Quote

Old   May 7, 2004, 14:23
Default Re: correct turbulence model
Posts: n/a
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.
  Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
OpenFOAM: LES turbulence model names Ollie OpenFOAM 5 January 7, 2013 11:24
Is this understanding of turbulence models correct? 3kha Main CFD Forum 3 January 31, 2011 22:31
build your own turbulence model with buoyancy Thomas Baumann OpenFOAM 11 November 23, 2009 09:53
Use of k omega turbulence model john_w OpenFOAM Running, Solving & CFD 2 September 22, 2009 05:15
Advanced Turbulence Modeling in Fluent, Realizable k-epsilon Model Jonas Larsson FLUENT 5 March 13, 2000 04:27

All times are GMT -4. The time now is 13:45.