In: Mechanical Engineering
Consider a diffuser in which air flows steadily. At the inlet of the diffuser the pressure, the temperature and the velocity of the air are 100 kPa, 110oC and 175 m/s, respectively. At the exit of the diffuser the pressure, the velocity of the gas and the area of the diffuser are 110 kPa, 15 m/s and 0.1 m2 , respectively. Accounting for an heat loss of 3 kJ/kg from the diffuser to the surroundings at 100 kPa and 25oC and assuming constant specific heats, determine (a) the exit temperature, (b) the rate of exergy change and (c) the second-law efficiency of the diffuser where ηII, diffuser = exergy output exergy input .