CFD Online Logo CFD Online URL
Home > Forums > FLUENT

Mesh Resolution to resolve turbulent boundary layer

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

LinkBack Thread Tools Display Modes
Old   October 20, 2013, 12:05
Default Mesh Resolution to resolve turbulent boundary layer
New Member
Join Date: Mar 2011
Posts: 6
Rep Power: 6
tongx051 is on a distinguished road
Hello guys,

I have several questions regarding mesh resolution for turbulence modeling.

1. What’s the mesh resolution required to solve a turbulence boundary layer with RANS?
2. What’s the mesh resolution required to solve a turbulence boundary layer with LES?
3. How does result look like if the mesh resolution is not enough(in Fluent)?
4. If wall function is applied, what the required resolution then? How many grids do I need inside the viscous sublayer and buffer layer? What grid growth rate is recommended?
5. Is the wall function for LES different from the standard wall function for RANS?
6. In LES simulation, what happens if no wall function is applied and near-wall mesh is not fine enough?
7. For modeling flow over several bluff body, there are typically flow separation, adverse pressure gradients, and wake interaction. Is wall function still valid in this case?
8. What’s recommended the mesh resolution for the free shear region (far from the wall) with LES and RANS?

I appreciate your help!

tongx051 is offline   Reply With Quote

Old   October 22, 2013, 00:18
Join Date: Dec 2012
Posts: 46
Rep Power: 4
jdrch is on a distinguished road
1) That depends on the physical scale of your model, but 5 prismatic layers is a good starting point
3) You might not even get a solution If you do, it may be physically wrong (obvious from inspection) or inaccurate
8) That depends on which region of the flow you're most interested in. If you're interested in the boundary layer, than it's OK to have a coarse mesh far from the wall
Find me online here.
jdrch is offline   Reply With Quote


turbulence modeling

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
[ICEM] Hybrid mesh for 2D boundary layer Bigio ANSYS Meshing & Geometry 32 January 9, 2014 11:26
Error finding variable "THERMX" sunilpatil CFX 8 April 26, 2013 07:00
Turbulent boundary layer resolution deji OpenFOAM 2 June 15, 2011 13:57
Adapt mesh without modifying boundary layer cells? Freeman FLUENT 0 February 22, 2009 15:11
How to control Minximum mesh space? hung FLUENT 7 April 18, 2005 09:38

All times are GMT -4. The time now is 01:40.