k-epsilon RNG Drag calculation limitations
 

Dear colleagues,

I am working on my masters thesis and i have done a static validation of a NACA 0024 airfoil. I used the k-epsilon RNG model.

I have done a calculation of the lift and drag coefficients at different angels of attack, for the drag coefficient i found that my values follow the same curve as the real ones but are way higher. Is there an explenation for this? I added an image of the problem.

I need find one to explain this in my thesis preferable with a reference to some klind of paper but i can't find an explanation.

Thank you!