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

How to add X and Y forces at a point

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 9, 2015, 12:29
Default How to add X and Y forces at a point
  #1
New Member
 
Join Date: Mar 2014
Posts: 5
Rep Power: 12
cgusty01 is on a distinguished road
Hello,

I am trying simulate a plasma actuator on an airfoil.

To do so, I need to add a force in the x and y directions to specific points in the domain. I am currently trying to add the force in "numerics_direct_mean.cpp". When the code passes through a certain array of points, I add the following to each location:

val_residual[1] = Volume * fx;
val_residual[2] = Volume * fy;

However, I am not getting the results I expect.

Do val_residual [1] and [2] add forces to the x and y directions, respectively? Or is there another way to add the forces?

The simulations use Euler equations with a NACA0012 airfoil at a 10 degree angle of attack.

Thank you
cgusty01 is offline   Reply With Quote

Old   February 10, 2015, 21:06
Default
  #2
hlk
Senior Member
 
Heather Kline
Join Date: Jun 2013
Posts: 309
Rep Power: 13
hlk is on a distinguished road
Quote:
Originally Posted by cgusty01 View Post
Hello,

I am trying simulate a plasma actuator on an airfoil.

To do so, I need to add a force in the x and y directions to specific points in the domain. I am currently trying to add the force in "numerics_direct_mean.cpp". When the code passes through a certain array of points, I add the following to each location:

val_residual[1] = Volume * fx;
val_residual[2] = Volume * fy;

However, I am not getting the results I expect.

Do val_residual [1] and [2] add forces to the x and y directions, respectively? Or is there another way to add the forces?

The simulations use Euler equations with a NACA0012 airfoil at a 10 degree angle of attack.

Thank you
Review the discretization of the Euler equations to make sure that setting the residual of the momentum flux to force*volume is actually what you want to do here. A good source is Numerical Computation of Internal & External Flows by Hirsch. Check that the residual is being updated in the linear system through a LinSysRes method, and review the other boundary conditions to see how these things are handled elsewhere in the code - there are often additional steps beyond setting a residual. It may be better to created a new boundary condition for what you are trying to do.
hlk is offline   Reply With Quote

Old   February 12, 2015, 14:16
Default
  #3
New Member
 
Join Date: Mar 2014
Posts: 5
Rep Power: 12
cgusty01 is on a distinguished road
Thank you for your answer.

I am trying to add a volumetric force, not a boundary force. I do call LinSysRes. My question is if elements 1 and 2 in val_residual[] correspond to the x- and y- momentum equations.
cgusty01 is offline   Reply With Quote

Old   February 18, 2015, 04:18
Default
  #4
New Member
 
Matt Wright
Join Date: Feb 2015
Posts: 5
Rep Power: 11
mattwright1234 is on a distinguished road
Hi,

Have you managed to get much further with this? I'm trying to do a similar thing for my 3rd year project without success. Would it be possible if you could post your code up?

Many Thanks
mattwright1234 is offline   Reply With Quote

Old   February 18, 2015, 13:17
Default
  #5
Super Moderator
 
Francisco Palacios
Join Date: Jan 2013
Location: Long Beach, CA
Posts: 404
Rep Power: 15
fpalacios is on a distinguished road
Hi all,

My recommendation is to take a look at
void CEulerSolver::Source_Residual(CGeometry *geometry, CSolver **solver_container, CNumerics *numerics, CNumerics *second_numerics, CConfig *config, unsigned short iMesh)

there are several examples there and, depending of the complexity of the source term, we directly compute the residual at that subroutine or we use the numerics structure.

In particular the free surface or time_spectral examples are quite clear.

Thanks for using SU2,

Best

Francisco Palacios
SU2 lead developer
fpalacios 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
an odd(at least for me!) reconstructPar error on a field immortality OpenFOAM Running, Solving & CFD 3 June 3, 2013 22:36
Forces for airfoil test case Martin_ OpenFOAM Running, Solving & CFD 1 July 2, 2012 11:58
FORCES don't run! C12Carbon OpenFOAM 0 September 10, 2011 07:34
How to add point source on boundary alvin11 OpenFOAM 0 December 2, 2010 07:29
CFX Post: Problems with moving point cloud for changing time steps spatialtime CFX 0 December 7, 2009 04:56


All times are GMT -4. The time now is 22:27.