$5\mathrm{.}20.$ Consider a flat plate at an angle of attack of $2$ in a Mach $2\mathrm{.}2$ airflow. $($Mach $2\mathrm{.}2$ is the cruising Mach number of the Concorde supersonic transport.$)$ The length of the plate in the flow direction is $202$ ft $,$ which is the length of the Concorde. Assume that the free$-$stream conditions correspond to a standard altitude of $50,000ft.$ The total drag on this plate is the sum of wave drag and skin friction drag. Assume that a turbulent boundary layer exists over the entire plate. The results given in Ch$.4$ for skin friction coefficients hold for incompressible flow only; there is a compressibility effect on Cf such that its value decreases with increasing Mach number. Specifically, at Mach $2\mathrm{.}2$ assume that the Cf given in Ch$.4$ is reduced by $20$ percent.

a$.$ Given all the preceding information, calculate the total drag coefficient for

b$.$ If the angle of attack is increased to $5,$ assuming that Cf stays the same,

c$.$ For these cases, what can you conclude about the relative influence of wave

Note that the vertical number in the figure is to power $-5$ not $5.$