This chapter mainly deal with the properties of two-dimensional airfoils at mach number above 0.3 but below 1, where the compressibil ity must be considered
5.1 Introduction The properties of airfoils are the same as the properties of a wing with infinite span. However, all real airplanes have wings of finite span. In the present chapter, we will apply our knowledge of airfoil properties to the analysis for finite wings. As we have mentioned in the previous chapter, the analysis for the aerodynamics of wings is separated in two steps.now, we are going on the second-step in Prandtl's philosophy of wing theory