Ans. 1251 N, 87.3°, 1.59, -0.204, 0.136 m.
(2) Consider air flows over two geometrically similar airplanes (1 and 2). The flow
over airplane 1 (wind tunnel) is at atmospheric pressure at a temperature of 20°C
with $V_\infty$ = 214 m/s, and the flow over airplane 2 has the properties of the standard
atmosphere at an altitude of 6000 m, with $V_\infty$ = 120 m/s. Determine the scale ratio
($L_2/L_1$) if the flows are to be dynamically similar with respect to:
(A) Reynolds number.
(B) Both Reynolds and Mach numbers.
Assume both viscosity ($\mu$) and speed of sound ($a$) to be proportional to $\sqrt{T}$.
Refer to air properties tables.
Ans. (A) 3.00 (B) 1.82
3) An airplane has a planform wing area of 280 m², an average mass of 150 ton, and
