In: Mechanical Engineering
Air flows through a short duct with a smooth inside surface and gradually changing flow area. The measured flow rate is equal to 288 lbm/min. At the duct inlet, the temperature is equal to 82 deg F, and the pressure is equal to 15 psia. The inlet velocity is equal to 924 ft/s. At the duct exit, the pressure is equal to 21.7 psia. (I.) Calculate the cross-sectional flow area of the duct inlet. (II.) Estimate the temperature and velocity at the duct exit. (III.) Explain why it is (or is not) possible that the duct shape is a diverging passage. (IV.) Explain why it is (or is not) possible that the duct is a converging-diverging passage. (Hint: use quantitative reasoning and compressible flow theory for parts III and IV.)