Thermodynamics

376 | ThermodynamicsT, KP 1 = 200 kPaT 1 = 950 KV 1 k2sbP 1T 2s a P 1k12>k2sbT 1 P 10.354>1.35480 kPa 1950 K2a200 kPa b 748 KThis gives an average temperature of 849 K, which is somewhat higher thanthe assumed average temperature (800 K). This result could be refined byreevaluating the k value at 749 K and repeating the calculations, but it is notwarranted since the two average temperatures are sufficiently close (doing sowould change the temperature by only 1.5 K, which is not significant).Now we can determine the isentropic exit velocity of the air from theenergy balance for this isentropic steady-flow process:e in e outh 1 V 1 22 h 2s V 22s2