Example 5 10, P 236 9th edition Refrigerant 134 a at 700 kPa , 70 deg C and 8 kg/min is cooled by water in a condenser until it exists as a saturated liquid at the same pressure. The cooling water enters the condenser at 300 kPa and 15 deg C and leaves at 25 deg C at the same pressure. Determine the mass flow rate of the cooling water required to cool the refrigerant.

Explain the difference laminar and turbulent flow. explain it with the shear stress and the velocity profiles.

Acompressor receives the shaft work to decrease the pressure of the fluid. a)- true b)- false

Apipe with an outside diameter of 15 cm is exposed to an ambient air and surrounding temperature of -20°c. the pipe has an outer surface temperature of 65°c and an emissivity of 0.85. if the rate of heat loss from the pipe surface is 0.95 kw per meter of length, the external convective heat transfer coefficient (h) is: (a) 12.5 w/m"k (b) 18.6 w/mk (c) 23.7 w/mk (d) 27.9 w/mk (e) 33.5 w/mk