3.16
Consider a Mach 2.5 flow of air entering a constant-area duct. Heat is added to this flow in the duct; the amount of heat added is equal to 30 percent of the total enthalpy at the entrance of the duct. Calculate the Mach number at the exit of the duct. Comment on the fluid dynamic significance of this problem, where the exit Mach number does not depend on the number for the actual heat added, but rather only on the dimensionless ratio of heat added to the total enthalpy of the inflowing gas. 

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(a) Problem 3.16 in dimensionless form assuming air is a calorically perfect gas with y 7/5. Also given initial pressure and temperature of 100 kPa, 600 K. Repeat for helium (4.003 kg/kmol), Calculate the exit Mach number, exit velocity, exit temperature, and heat transfer per unit mass. AIR y = 7/5 M2= uz m/s, T2=, K, q = kJ/kg Helium y = 5/3 М ,Uz = m/s, T2= K, q = kJ/kg Complete the discussion as given in the problem. (a) Problem 3.16 in dimensionless form assuming air is a calorically perfect gas with y 7/5. Also given initial pressure and temperature of 100 kPa, 600 K. Repeat for helium (4.003 kg/kmol), Calculate the exit Mach number, exit velocity, exit temperature, and heat transfer per unit mass. AIR y = 7/5 M2= uz m/s, T2=, K, q = kJ/kg Helium y = 5/3 М ,Uz = m/s, T2= K, q = kJ/kg Complete the discussion as given in the problem.