ⓘ Cl–α, zero-lift angle, and Cmc/4 are calculated from thin-airfoil theory (potential flow, small angle approximation).
Cl = 2π(α − αL=0), valid in the linear region. Stall (~12–16°) is empirically smoothed.
Drag Cd is APPROXIMATELY modeled with a thickness-dependent parabolic polar (Cd = Cd₀ + k·Cl²) —
actual values depend on Reynolds number, surface roughness, and viscous effects.