CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > General Forums > Main CFD Forum

Common air foil friction drag data

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 5, 2014, 06:15
Default Common air foil friction drag data
  #1
New Member
 
Uncle Jack
Join Date: Aug 2014
Posts: 1
Rep Power: 0
FCBK is on a distinguished road
Folks, newbie here. Quick question, I am trying to find the Cdf data of common airfoils like NACA0015, 0020, 0025, etc., especially under low reynolds number conditions. I was reading a report lately that gave approximately 0.2 Cd, but 0.07 Cdp for NACA0020. This means friction drag accounts for 70% of the drag for an airfoil. RE # 150,000-200,000
Basically we are talking about a 10" long NACA0020 foil moving at 25mph.

This sounds really odd. I always thought air friction should be quite little in normal air conditions (low viscosity, etc.). But this clearly says 70%!!! What did I miss?
FCBK is offline   Reply With Quote

Old   August 5, 2014, 10:57
Default
  #2
Senior Member
 
Troy Snyder
Join Date: Jul 2009
Location: Akron, OH
Posts: 219
Rep Power: 18
tas38 is on a distinguished road
I believe your question is in regard to the contributions of pressure drag and skin friction drag to the overall drag on an airfoil. Given a low angle of attack, the main drag component will be due to skin friction. It is not until higher higher angles of attack (leading to flow separation) that the pressure drag becomes appreciable.
tas38 is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Possible Bug in pimpleFoam (or createPatch) (or fluent3DMeshToFoam) cfdonline2mohsen OpenFOAM 3 October 21, 2013 10:28
air bubble is disappear increasing time using vof xujjun CFX 9 June 9, 2009 08:59
Improve accuracy on air foil blade simulation? Bian CFX 4 December 12, 2006 12:29
thermodynamic data for air ilyongyoo Main CFD Forum 2 March 6, 2005 10:19
Air foil, drag coefficient Amit FLUENT 2 April 16, 2004 01:40


All times are GMT -4. The time now is 08:35.