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

Drag under Euler formulation

Register Blogs Community New Posts Updated Threads Search

Like Tree1Likes
  • 1 Post By fpalacios

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   July 23, 2013, 09:42
Default Drag under Euler formulation
  #1
New Member
 
MENDES BORTOLAZZI Andre
Join Date: Jun 2013
Posts: 7
Rep Power: 12
Bortolazzi is on a distinguished road
Hi developers,

I would like to ask you how the drag of a profile is computed using Euler analysis. In another post, I've been told the total drag was computed by integrating over the surface, but how is the shear stress tension localy computed?
Are the concepts of displacement thickness and momentum thickness employed?

Thanks in advance,

Andre
Bortolazzi is offline   Reply With Quote

Old   August 19, 2013, 12:32
Default
  #2
Super Moderator
 
Francisco Palacios
Join Date: Jan 2013
Location: Long Beach, CA
Posts: 404
Rep Power: 15
fpalacios is on a distinguished road
Hi Andre,
To compute the Drag (inviscid and viscous) we perform a direct integration of the forces on the surface. More details in http://su2.stanford.edu/documents/SU2_AIAA_ASM2013.pdf

And the subroutines in the code:
void CEulerSolver::Inviscid_Forces(CGeometry *geometry, CConfig *config)
void CNSSolver::Viscous_Forces(CGeometry *geometry, CConfig *config)

Best,
Francisco

Quote:
Originally Posted by Bortolazzi View Post
Hi developers,

I would like to ask you how the drag of a profile is computed using Euler analysis. In another post, I've been told the total drag was computed by integrating over the surface, but how is the shear stress tension localy computed?
Are the concepts of displacement thickness and momentum thickness employed?

Thanks in advance,

Andre
beatlejuice likes this.
fpalacios is offline   Reply With Quote

Old   August 20, 2013, 08:14
Default
  #3
New Member
 
MENDES BORTOLAZZI Andre
Join Date: Jun 2013
Posts: 7
Rep Power: 12
Bortolazzi is on a distinguished road
Hi Francisco,

Thanks for your reply. In the end, I guess I was just strugling with spurious drag, because SU2 provided some small values for drag coefficient when running a bidimensional Euler analysis in low Mach flow (thus, no drag). I was confused, because the spurious drag was increasing with the angle of attack, but after some research, I found out this is the normal behaviour for numerical drag.
Thanks again for your attention.

Best regards,

Andre
Bortolazzi is offline   Reply With Quote

Reply


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
Drag law customization (Euler) Aris FLUENT 0 December 1, 2006 09:39
Dimensionless formulation of Euler equations jvn Main CFD Forum 3 July 8, 2004 13:29
Drag formulation REMY FLUENT 0 March 10, 2002 14:05
Drag formulation remy Main CFD Forum 0 March 10, 2002 13:05
Inviscid Drag at subsonic, subcritical Mach # Axel Rohde Main CFD Forum 1 November 19, 2001 12:19


All times are GMT -4. The time now is 21:40.