CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > SU2

Direct differentiation method - negative gradient

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 28, 2018, 10:06
Default Direct differentiation method - negative gradient
  #1
New Member
 
Evgeniy
Join Date: Oct 2017
Posts: 5
Rep Power: 8
Evgeniy is on a distinguished road
Dear su2 people,

i'm doing verification analysis of AD discrete adjoint method on 3D two element wing model with FFD box. When i calculated objective function gradient by using forward direct differentiation method i found that it agrees with adjoint gradient (of Lift and Drag) only if i multiply it by -1 (see attachment).
Maybe it's relevant that in my model Y axis is aligned with Lift force direction, X - with drag and Z - with side force.
Is this just coincidence of wrong results or direct differentiation method calculates negative gradient?

Thanks,
Evgeniy
Attached Files
File Type: pdf mid_sec_grad.pdf (16.9 KB, 8 views)
Evgeniy 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
pisoFOAM (LES) - internal pipe flow - convergence gu1 OpenFOAM Running, Solving & CFD 0 January 11, 2018 17:39
negative pressure gradient in cone-shaped pipe Pawel Zdunek Lounge 0 April 29, 2017 16:16
matlab code for Conjugate Gradient method in conduction problem raminostadi ANSYS 0 February 6, 2017 06:16
free package for the "direct method" ztdep Main CFD Forum 0 May 31, 2006 12:55
Direct calculation of temperature gradient J.W.Ryu FLUENT 5 December 27, 2001 07:39


All times are GMT -4. The time now is 03:53.