Cl-alpha, 3d airfoil problem.

levonlarson · February 14, 2011, 18:55

I am trying to determine dCl/d(alpha) for a 3d airfoil however Cl is barely changing (0.38-0.42) as I vary alpha (0-10 degrees), any help?

I only need preliminary results so my mesh is fairly coarse.

Thanks.

montag dp · February 15, 2011, 02:07

If you are reporting Cl from the monitors, are you sure your reference values are correct?

If that's not it, I'd try refining your mesh first.

levonlarson · February 15, 2011, 09:29

My reference values are good, Fluent is simply underestimating the force produced by the airfoil as it changes angles. I also forgot to mention that my first mesh refinement did not fix the problem.

I am very closely following the 2D wing tutorials, at this point my wing is just a 2D airfoil that has been extruded.

February 14, 2011, 18:55	Cl-alpha, 3d airfoil problem.	#1
levonlarson New Member Levon Join Date: Feb 2011 Posts: 3 Rep Power: 15	I am trying to determine dCl/d(alpha) for a 3d airfoil however Cl is barely changing (0.38-0.42) as I vary alpha (0-10 degrees), any help? I only need preliminary results so my mesh is fairly coarse. Thanks.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Problem Meshing Airfoil	erodv	OpenFOAM	12	January 11, 2012 17:46
Problem with boundary condictions in an airfoil	bego	OpenFOAM Running, Solving & CFD	0	September 22, 2010 05:56
cyclic BC from gambit to openfoam for cascade airfoil problem	maverick	OpenFOAM	0	April 13, 2010 15:18
[FloWorks] Request advice for an airfoil calculation problem	Bogey Jammer	Main CFD Forum	0	September 29, 2009 17:06
problem specifying alpha at inlet during a parallel run	phsieh2005	OpenFOAM Running, Solving & CFD	2	August 13, 2009 08:23

February 15, 2011, 02:07		#2
montag dp Member Join Date: Jul 2010 Posts: 38 Rep Power: 15	If you are reporting Cl from the monitors, are you sure your reference values are correct? If that's not it, I'd try refining your mesh first.

February 15, 2011, 09:29		#3
levonlarson New Member Levon Join Date: Feb 2011 Posts: 3 Rep Power: 15	My reference values are good, Fluent is simply underestimating the force produced by the airfoil as it changes angles. I also forgot to mention that my first mesh refinement did not fix the problem. I am very closely following the 2D wing tutorials, at this point my wing is just a 2D airfoil that has been extruded.