# Lift Coefficient vs Angle of Attach for Pitching Airfoil

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January 29, 2014, 03:16
Lift Coefficient vs Angle of Attach for Pitching Airfoil
#1
New Member

Musa
Join Date: Mar 2012
Posts: 14
Rep Power: 14
Hi Everyone,
I am performing airfoil Pitching in fluent using UDF. I am using this equation

alpha = alpha(o)+alpha(a)*sin(Wt)
alpha(o) = mean angle of attack (10)
alpha(a) = pitching amplitude (15)

My problem however is how to plot the lift coefficient vs AOA as shown in the picture below. Normally in the static case, you specify the angle of attack for x and y in fluent and report the forces after simulation for each angle of attack. Which means you have to run a lot of cases if your aoa is between (-5 to 25).

However looking at the pitching case and the picture I do not know to plot it. Please any help will be appreciated.

Regards
Franklyn
Attached Images

 July 9, 2014, 04:26 #2 New Member   Pras Join Date: Apr 2014 Posts: 13 Rep Power: 12 Hi, Could you help me with the solution to the problem you mentioned. How to determine the Cl vs AOA for pitching airfoil?

July 9, 2014, 11:00
#3
Senior Member

Syavash Asgari
Join Date: Apr 2010
Posts: 473
Rep Power: 18
Quote:
 Originally Posted by fkanyako Hi Everyone, I am performing airfoil Pitching in fluent using UDF. I am using this equation alpha = alpha(o)+alpha(a)*sin(Wt) alpha(o) = mean angle of attack (10) alpha(a) = pitching amplitude (15) My problem however is how to plot the lift coefficient vs AOA as shown in the picture below. Normally in the static case, you specify the angle of attack for x and y in fluent and report the forces after simulation for each angle of attack. Which means you have to run a lot of cases if your aoa is between (-5 to 25). However looking at the pitching case and the picture I do not know to plot it. Please any help will be appreciated. Regards Franklyn
Hi,
Writing a UDF is one tool which can help you plot Cl vs. AOA.
But have in mind that solution of a dynamic pitching airfoil is different from the static airfoil.
Goodluck

 July 16, 2014, 07:35 #4 New Member   Pras Join Date: Apr 2014 Posts: 13 Rep Power: 12 Hi, Does anybody have any example of an airfoil pitching UDF with the AOA part on it, which will give me the AOA at every time step? Regards, Pras