Consider a diamond-shaped airfoil. The maximum thickness is 0.04 and occurs at mid-chord. The freestream Mach number is 2.0, and the airfoil is operating at a 5 degree angle of attack. 

a) Find the expressions for the lift coefficient, drag coefficient, lift to drag ratio, and the moment coefficient about the leading edge using Ackert’s rule. 

b) Sketch Cp vs x/c for the upper and lower surfaces (on the same graph). 

c) Repeat the calculations using the exact theory (Shock-expansion theory). Compare your results with Ackert’s rule.