# Drag Calculation in SU2

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 April 18, 2014, 03:56 Drag Calculation in SU2 #1 New Member   Y Yang Join Date: Nov 2012 Posts: 25 Rep Power: 10 Dear All, Is there a way to get drag coefficient separately in the aerodynamic coefficient calculation like: pressure drag, viscous drag, and induced drag? Regards, Yosheph

April 18, 2014, 10:39
#2
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Francisco Palacios
Join Date: Jan 2013
Location: Long Beach, CA
Posts: 404
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Quote:
 Originally Posted by andromeda91 Dear All, Is there a way to get drag coefficient separately in the aerodynamic coefficient calculation like: pressure drag, viscous drag, and induced drag? Regards, Yosheph
Unfortunately, not yet, but we are working on that kind of output. The viscous drag is computed and you have the value inside the code. Just look at the subroutine
void CNSSolver::Viscous_Forces(CGeometry *geometry, CConfig *config)
in the file solver_direct_mean.cpp

Thanks for using SU2,
Francisco

April 21, 2014, 05:24
#3
New Member

Y Yang
Join Date: Nov 2012
Posts: 25
Rep Power: 10
Dear Francisco,

So does it mean that no pressure drag and induced drag calculated for the drag coefficient computation in the current version of SU2?

Regards,

Yosheph Yang

Quote:
 Originally Posted by fpalacios Unfortunately, not yet, but we are working on that kind of output. The viscous drag is computed and you have the value inside the code. Just look at the subroutine void CNSSolver::Viscous_Forces(CGeometry *geometry, CConfig *config) in the file solver_direct_mean.cpp Thanks for using SU2, Francisco

 April 24, 2014, 05:41 #4 Super Moderator   Thomas D. Economon Join Date: Jan 2013 Location: Stanford, CA Posts: 271 Rep Power: 11 Hi Yosheph, We compute the drag as a total integrated force on the specified surfaces using the pressure and viscous stresses at each of the computational nodes. So, while each type of drag (wave, skin friction, viscous pressure drag, etc.) will be accounted for in this type of calculation through the pressure and viscous stresses, we are not currently able to decompose the total drag into contributions for each different type. We are working to improve the force outputs available on the surfaces, and I might also mention that there are techniques for this type of drag decomposition (in particular, ONERA has been working on drag breakdown/extraction methods for some years). Cheers, Tom