Oxygen enters an insulated 14.2-cm-diameter pipe with a velocity of 60 m/s. at the pipe entrance, the oxygen is at 240 kpa and 20°c; and, at the exit, it is at 200 kpa and 18°c calculate the rate at which entropy is generated in the pipe.

Along 8-cm diameter steam pipe whose external surface temperature is 900c connects two buildings. the pipe is exposed to ambient air at 70c with a wind speed of 50 km/hr blowing across the pipe. determine the heat loss from the pipe per unit length. (b) air at 500c enters a section of a rectangular duct (15 cm x 20 cm) at an average velocity of 7 m/s. if the walls of the duct are maintained at 100c. a) the length of the tube for an exit temperature of the air to be 40 0c. b)the rate of heat transfer from the air. c) the fan power needed to overcome the pressure drop in this section of the duct.