Air at a stagnation temperature of 460 K
Air at a stagnation temperature of 460 K and stagnation pressure of 2.7 kPa flows isentropic ally through a convergent nozzle which feeds an insulated constant-area duct. The duct is 25 cm in diameter and 0.6 m long. If the average friction factor in the duct, f, is 0.005, determine the maximum air flow rate and compare it with the flow through the nozzle in the absence of the duct. What is the maximum back pressure for choking to occur in both cases?