CFD Online Logo CFD Online URL
Home > Forums > Main CFD Forum

Help on induced drag in VLM

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

LinkBack Thread Tools Display Modes
Old   May 14, 2010, 13:44
Default Help on induced drag in VLM
New Member
Aneesh Goly
Join Date: May 2010
Posts: 1
Rep Power: 0
aaneesh is on a distinguished road

I am doing analysis of ocean current turbine using vlm. i computed lift force and Can anyone please let me know how to calculate the induced drag (or any reference).

aaneesh is offline   Reply With Quote

Old   August 25, 2010, 05:07
New Member
César Vecchio
Join Date: Jul 2010
Location: Córdoba, Argentina
Posts: 21
Rep Power: 7
CAVT is on a distinguished road
If you where able to calculate lift force then induce drag is pretty much the same. I suppose you calculated the force on each panel by:

Fi=gammai*rho*V*bi (Kutta's formula)

Now, as Fi is a force it has three components in x,y,z respectively, usually in body axes. So:


Then to convert those total components to wind axes simply apply a rotation matrix (Euler angles) which depends on attack and yaw angles solely:

[Di,C,L]'=[rotation matrix]*[Fx,Fy,Fz]'

Di is induced drag, C is lateral force and L is lift. To obtain coefficients divide each of them by q*S.
If you're not happy with my answer, you can check the books by Jack Moran (provides sample VLM code) or the good ol' Katz & Plotkin. You can also check the source code of Tornado, AVL, VLMpc or VorStab, they are all open source VLM codes, and reliable.
CAVT is offline   Reply With Quote


cdi, induced drag, vlm

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
induced drag Amir FLUENT 0 March 5, 2009 11:08
Help me please, A.S.A.P ( about induced drag ) deus CFX 0 June 22, 2008 09:33
Induced drag in panel method andre Main CFD Forum 1 March 8, 2008 11:58
Induced drag from N-S flow-field Jarmo Monttinen Main CFD Forum 0 January 15, 2004 19:10
Induced Drag Reduction Erich Main CFD Forum 1 March 22, 1999 05:39

All times are GMT -4. The time now is 22:16.