Answer:
h = 89.6 W/m^2 K
Explanation:
Given data:
altitude is 10 km
speed of airplane is 800 km/h
coeeficent of frcition is 0.0016
From standard table
for - 50 degree C and 1 atm pressure
Cp= 999 J/kg K
P_r = 0.744 for reynold's analogy
From Gas law we have
[tex]\rho = \frac{P}{RT} = \frac{26.5}{.287 \times (-50 + 273)}[/tex]
[tex]\rho = .414 kg/m^3[/tex]
from Modified Reynolds analogy we have
[tex]\frac{Cf}{2} = \frac{h}{\rho v Cp} P_r^{2/3}[/tex]
solving for h so we have
[tex]h = \frac{Cf}{2} \frac{\rho Cp v}{P_r^{2/3}}[/tex]
[tex]h = \frac{0.0016}{2} \frac{0.414 \times 9999 \times 800 \times \frac{10^3}{3600}}{.744^{2/3}}[/tex]
h = 89.6 W/m^2 K
