ME3251 Flow of Compressible Fluids Dr. T. J. Barber Spring 2013 Problem 22: Consider a supersonic flow with an upstream Mach number of 4 and a pressure of 1 atm. This flow is first expanded around an expansion corner with 1 = 15 degrees, and then compressed through a compression corner with an equal angle of 2 = 15 degrees so that it is returned to the original upstream direction. Calculate the Mach number and pressure downstream of the final compression corner. Use both shock – expansion and weak shock – expansion theory. Problem 23 Using both shock-expansion theory and weak-shock theory, calculate the lift and drag [coefficient] on two symmetrical diamond airfoils, one with a semiangle = 30 and one of = 150. Both are at zero angle of attack to the freestream. The upstream Mach number and pressure are 2.0 and 2116 lb/ft2 respectively. The maximum thickness of the airfoil is t = 0.5 ft. Assume a unit length of 1 ft in the spanwise direction [perpendicular to the page]. Compare the results and explain them.