Not getting accurate CL and CD values in fluent
 

I am fairly new to Ansys and this is my first project on fluent. I have modeled a half symmetrical wing inside a flow domain. The mesh size is about 2mil with average skewness of 0.23.


My fluent settings are-

MODEL- Realizable K-epsilon with non-equilibrium wall function.


REFERENCE VALUES(Area)- 1.45(This is half the area of the wing i wanna model)


REFERENCE VALUES(length) -0.7(chord of the wing)


SOLUTION METHOD - Coupled second order upwind


I am calculating the CL and CD at 0 aoa and comparing my fluent results with the results I am getting from XFLR5. The values are varying a lot and are nowhere close. Am I doing something wrong? How can I improve my results?