Thermodynamics

5–31 Reconsider Prob. 5–30. Using EES (or other)software, investigate the effect of the inlet areaon the mass flow rate, exit temperature, and the exit area. Letthe inlet area vary from 50 cm 2 to 150 cm 2 . Plot the finalresults against the inlet area, and discuss the results.5–32 Steam at 5 MPa and 400°C enters a nozzle steadilywith a velocity of 80 m/s, and it leaves at 2 MPa and 300°C.The inlet area of the nozzle is 50 cm 2 , and heat is being lostat a rate of 120 kJ/s. Determine (a) the mass flow rate of thesteam, (b) the exit velocity of the steam, and (c) the exit areaof the nozzle.5–33E Air enters a nozzle steadily at 50 psia, 140°F, and150 ft/s and leaves at 14.7 psia and 900 ft/s. The heat lossfrom the nozzle is estimated to be 6.5 Btu/lbm of air flowing.The inlet area of the nozzle is 0.1 ft 2 . Determine (a) the exittemperature of air and (b) the exit area of the nozzle.Answers: (a) 507 R, (b) 0.048 ft 25–34 Steam at 3 MPa and 400°C enters an adiabaticnozzle steadily with a velocity of 40 m/sand leaves at 2.5 MPa and 300 m/s. Determine (a) the exittemperature and (b) the ratio of the inlet to exit area A 1 /A 2 .5–35 Air at 600 kPa and 500 K enters an adiabatic nozzlethat has an inlet-to-exit area ratio of 2:1 with a velocity ofP 1 = 3 MPaT 1 = 400°CV 1 = 40 m/sSTEAMFIGURE P5–34P 2 = 2.5 MPaV 2 = 300 m/s120 m/s and leaves with a velocity of 380 m/s. Determine(a) the exit temperature and (b) the exit pressure of the air.Answers: (a) 436.5 K, (b) 330.8 kPa5–36 Air at 80 kPa and 127°C enters an adiabatic diffusersteadily at a rate of 6000 kg/h and leaves at 100 kPa. Thevelocity of the airstream is decreased from 230 to 30 m/s as itpasses through the diffuser. Find (a) the exit temperature ofthe air and (b) the exit area of the diffuser.5–37E Air at 13 psia and 20°F enters an adiabatic diffusersteadily with a velocity of 600 ft/s and leaves with a lowvelocity at a pressure of 14.5 psia. The exit area of the diffuseris 5 times the inlet area. Determine (a) the exit temperatureand (b) the exit velocity of the air.5–38 Carbon dioxide enters an adiabatic nozzle steadily at1 MPa and 500°C with a mass flow rate of 6000 kg/h andP 1 = 13 psiaT 1 = 20°FV 1 = 600 ft/sAIRFIGURE P5–37EChapter 5 | 259P 2 = 14.5 psiaV 2