Chapter 12, Problem 35P

High-speed aircraft use “air data computers” to compute air speed from measurement of the difference between the stagnation and static pressures. Plot, as a function of actual Mach number M, for M = 0.1 to M = 0.9, the percentage error in computing the Mach number assuming incompressibility (i.e., using the Bernoulli equation), from this pressure difference. Plot the percentage error in speed, as a function of speed, of an aircraft cruising at 12 km altitude, for a range of speeds corresponding to the actual Mach number ranging from M = 0.1 to M = 0.9.