# Drag force calculation using URANS

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 September 13, 2017, 13:26 Drag force calculation using URANS #1 New Member   Felipe Silva Maffei Join Date: Dec 2015 Posts: 11 Rep Power: 9 Hi, I'm working in my end-of-graduation-course paper, it's ,briefly speaking, a study about the flow behavior under a NACA0015 with a flap and gurney flap. Becouse of the size mesh and turbulence model, a steady state simulation do not converge (residual target 1e-6), so I used URANS. I know how to calculate the average of variables, but, here is my question, can I calculate the average of drag force? Last edited by Maffei; September 13, 2017 at 13:28. Reason: erro in title

 September 13, 2017, 20:06 #2 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,580 Rep Power: 141 If I was doing this I would: * Make a monitor point which had the drag force. * Run the simulation * make a solver monitor to display the drag force for each time step. Make the X axis time, not iteration number * Export the data to a csv file * Load the CSV into excel, matlab, python or whatever you use for mathematics and calculate time averages or whatever you want. juliom likes this.

 September 16, 2017, 21:48 #3 New Member   Felipe Silva Maffei Join Date: Dec 2015 Posts: 11 Rep Power: 9 thanks for answering, I need to do the average of drag force acting under the airfoil,I think that this resolution will not work. Am I correct?

 September 17, 2017, 22:01 #4 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,580 Rep Power: 141 You think the Resolution of what will not work?

 September 18, 2017, 01:22 #5 New Member   Felipe Silva Maffei Join Date: Dec 2015 Posts: 11 Rep Power: 9 no, my question is whether I can set up the bondary at CFX pre.

 September 18, 2017, 01:38 #6 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,580 Rep Power: 141 I do not understand your question. Can you say what your question is again, but more clearly?

 Tags cfd, cfx, urans