Cd max of airfoil
 

Dear friends

i am doing my university project on a naca airfoil with same profiled flap. i am using RNG k-epsilon model with standard wall function, in case that Angle of attack 10 degrees and flap deflection 20 degrees .
when i give option to print and plot drag an lift coefficients, i am getting error like read-data: invalid plot file format

i am attaching the mesh file of my problem

can any one help me how to avoid that error and how to find the Cd max and Cl max

Thank you