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

Induced drag in panel method

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   March 8, 2008, 05:11
Default Induced drag in panel method
  #1
andre
Guest
 
Posts: n/a
I have written a panel method of my own, 1st order, flat panels, for the analysis of sailplanes. Everything works fine, except that the induced drag calculated from panel pressure forces is way too high. Many publications recommend instead to get the induced drag from far field analysis, and that's OK, I've done it for a VLM. However for a panel method, I don't know how to calculate the strip's circulations from the doublet strengths.

Can anybody help ?

Thanks
  Reply With Quote

Old   March 8, 2008, 11:58
Default Re: Induced drag in panel method
  #2
Leo Lazauskas
Guest
 
Posts: n/a
For flat wings it is sometimes easier to use the leading edge suction force instead of a direct calculation of induced drag.

A good test of your code is a circular wing.

The exact lift slope is CL/alpha = 1.79002303, and the moment is CM/alpha = -0.466174.

For the induced drag I get Cdi/alpha^2 approx = 0.802, and CS/alpha^2 approx =0.982 for the leading edge suction force.

Don't expect reliable results from VLM for the circular wing. Some panel densities will give Ok results, others may give nonsense.

If you need more detail, search for the PhD thesis of D.W.F. Standingford.

Good luck, Leo.

  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
source panel method joel guerrero Main CFD Forum 5 November 1, 2012 22:47
Isolating wing induced drag component siw CFX 2 June 22, 2010 11:21
Please: Looking for a Panel method or vortice lattice for windmill be_inspired Main CFD Forum 10 April 1, 2009 17:53
Why use a panel method? gocarts Main CFD Forum 2 April 22, 2007 23:50
Panel Method Zeynep Cehreli Main CFD Forum 5 February 8, 2004 06:24


All times are GMT -4. The time now is 00:05.