Why my fluent calculating a 2D airfoil has a higher value of cd?

I use a 2D naca2412 , 200000Re, 0 deg.I set refernce area as the airfoil chord.Mesh type is C type.The result of cd is 0.02 but according to xfoil and airfoiltools , the cd should be about 0.01 ....

20 September 2021 6,834 6 View