Carbon dioxide enters an adiabatic nozzle at 1200 K with a velocity of 75 m/s and leaves at 400 K. Assume constant specific heats at room temperature. Determine the Mach number at the inlet. The gas constant of carbon dioxide is R = 0.1889 kJ/kg·K and k = 1.288. The Mach number at the inlet is

The Mach number at the inlet is 0.14

Explanation:

Mach number = v/a

v = 75 m/s

a = sqrt(kRT)

k = 1.288

R = 0.1889 kJ/kg.K = 0.1889×1000 = 188.9 J/kg. K

T = 1200 K

a = sqrt(1.288×188.9×1200) = sqrt(291963.84) = 540.34 m/s

Mach number = 75m/s ÷ 540.34m/s = 0.14

the positions which points up in upward carbon and down in downward carbon are axial

and vice versa holds true for equatorial positions

so the correct answer with labelled diagram will be