CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > STAR-CCM+

Turbulent Length Scale and Intensity for Airfoil

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

Reply
 
LinkBack Thread Tools Display Modes
Old   April 5, 2011, 10:01
Default Turbulent Length Scale and Intensity for Airfoil
  #1
New Member
 
Shamim Islam
Join Date: Mar 2011
Posts: 9
Rep Power: 5
shamim is on a distinguished road
Send a message via Yahoo to shamim Send a message via Skype™ to shamim
Hello All,

I am running a simulation of 3D wing (NACA 2412) of chord length 1m and span 0.3m in STAR CCM 4.04. I am using Spalart-Allmaras model. Now, I am in great trouble on setting the value of Turbulent Length Scale and Intensity. I am not getting any clue how to set the value of this parameter.

Anybody can help me- how can I set the value of Turbulent Length Scale and Intensity? I highly appreciate your suggestions.

Shamim
shamim is offline   Reply With Quote

Old   August 2, 2011, 07:47
Default
  #2
Member
 
Join Date: Mar 2009
Posts: 85
Rep Power: 7
husker is on a distinguished road
Hi Shamim,

Let me say that the wing you are on to is very interesting. Due to its very low aspect ratio the tip-vortex will dominate the entire flow which is essentially very hard to investigate.

However if you would like to calculate lift and drag, you can google some NACA papers and find some focused on determining 3D characteristics of an airfoil from 2D characteristics. As input, you can find easily 2D characteristics of 2412 or calculate via CFD.

I think turbulence length scale and intensity are should be thought secondarily. While simulating the flow around an airfoil, those parameters are applied to the boundary conditions, especially to the free-stream. For a such flow, turbulence intensity can be taken between %1 and %5. Turbulence length scale isn't very easy to determine but initially you can accept it 10 or 25 percent of the wing chord.
husker is offline   Reply With Quote

Reply

Tags
s-a, turbulent length scale

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
k-epsilon: Defining turbulent intensity and length scale? klausb OpenFOAM 0 January 23, 2011 07:28
Turbulence length scale and integral length scale rizhang CFX 1 September 10, 2009 06:38
how to calculate Turbulent Length Scale nuimlabib Main CFD Forum 2 August 18, 2009 04:22
Turbulent intensity length KIAN FLUENT 2 February 24, 2000 20:43


All times are GMT -4. The time now is 16:00.