The traditional approach to axial-flow compressor aerodynamic design was to use various families of airfoils as the basis for blade design. American practice was based on various families defined by the National Advisory Committee for Aeronautics (NACA), the most popular being the 65-series family. British practice often centered about the C-series families, using circular-arc or parabolic-arc camberlines. As design requirements began to favor transonic operation, double-circular-arc blades became popular. The performance characteristics of these airfoil families are well understood due to extensive experimental cascade testing, much of which is available in the literature.

In recent years, use of blades designed...