What percentage of speed reduction is required if the

Question

1. The average chord of an airplane's wing is 4 m and it flies at sea level (ρ = 1.225 kg/m³, μ = 1.78 × 10^-5 N s/m², T = 288 K, γ = 1.4) at a speed of 1000 km/h. Calculate the Mach number and the Reynolds number based on the wing average chord.

2. The airplane of the previous problem flies at the same speed of 1000 km/h, but at an altitude of 10,000 m, where ρ = 0.413 kg/m³, μ = 1.46 × 10^-5 N s/m², T = 223 K, γ = 1.4.

(a) Calculate the Mach number and the Reynolds number based on the wing average chord.

(b) What percentage of speed reduction is required if the airplane must fly at the same Mach number as calculated for sea level (in the previous problem)?