Air at 80 kPa and 127°C enters an adiabatic diffuser steadily at a rate of 6000 kg/h and leaves at 100 kPa. The velocity of the airstream is decreased from 230 to 30 m/s as it passes through the diffuser. Find (a) the exit temperature of the air and (b) the exit area of the diffuser.?

he refrigerant R-134a enters the compressor of a refrigeration machine at a pressure of 140kPa and a temperature of -10°C, and exits at a pressure of 1MPa. The volumetric flow of the refrigerant entering the compressor is 0.23m3/minute. The refrigerant enters the throttling valve at a pressure of 0.95MP and at 30 °C, and exits the evaporator as saturated steam at -18 °C. The adiabatic efficiency of the compressor is 78%. Show the cycle in the T-s diagram. a) Power required to start the compressor b) Calculate the heat withdrawn from the cooled environment in unit time, COPSM=? c) Calculate how much the pressure of the refrigerant drops between the evaporator and the compressor and how much the heat gain is.

A pump increases the water pressure from 8 kPa at the inlet to 700 kPa at the outlet. Water enters this pump at 41.51°C through a 1.704-cm-diameter opening and exits through a 1.154-cm-diameter opening. Determine the velocity of the water at the outlet in m/s when the mass flow rate through the pump is 1.101 kg/s. The specific volume of incoming water is 1.426 × 10-3 m3/kg.

Air is compressed by an adiabatic compressor from 100 kPa and 20°C to 1.8 MPa and 400°C. Air enters the compressor through a 0.15- m² opening with a velocity of 30 m/s. It exits through a 0.084-m² opening. Calculate the mass flow rate of air and the required power input. The constant pressure specific heat of air at the average temperature of 210°C = 483 K is cp= 1.026 kJ/kg-K. The gas constant of air is R = 0.287 kPa-m³/kg-K. 3 The mass flow rate of air is The required power input is kg/s. KW.