forceCoeffs lRef and Aref ??
 

Hi guys, what is the value to put in lRref and Aref when i define forceCoeffs? From OF' s libraries I've see that lRef is referred to lenght scale for moment but I don't understand on what I have to base. And for Aref :confused:?
P.S. I have an airfoil with a chord of 0.5459 m

and other question...the direction of drag is the opposite of flux, right? If this is true, for the tutorial airfoil2D because I have an angle of attack of 8° positive and then the y component of U is positive, the dragdir for me is (-cos8 -sin8 0). Is it right?

http://www.cfd-online.com/Forums/ope...lref-aref.html

Have you seen this thread?