Hi Guys

How can i find the coordinates of an airfoil at different angle of attacks. I want to simulate a flow over a NACA 0018 airfoil but i have coordinates for it only at 0 degree angle of attack. I need to get its coordinates @ 3, 9 and 12 degrees angles of attack? Thanks in advance

Regards Usman

Rotate the airfoil. The transformation can be found in any number of references. Or rotate the freestream flow vector.

Can you explain in a bit more detail how can i rotate the airfoil. What do you mean by number of refernce? I will not be able to use freestream flow vector in my case! Thanks

Usman

In order to rotate each given point of your airfoil, use simple formulae available, e.g., at http://en.wikipedia.org/wiki/Rotation_(mathematics)

Thanks AK i will look into it!

Usman

Which formulas exactly are we suposse to use to find the co-ordinates for airfoil at an angle of incidence. I am very confused here.

Usman

Let (x,y) be the frame of reference in which the inflow velocity is (U,0), and (x',y') be coordinates of an airfoil point.

Now if you rotate the point (x',y') with respect to (x,y) clockwise at an angle "alpha" then

x= x'cos(alpha)+y'sin(alpha);

y= -x'sin(alpha)+y'cos(alpha)

Thank you very much AK.

Regards Usman