The surface of a 50-mm-diameter, thin-walled tube is maintained at 100°c. in one case air is in cross flow over the tube with a temperature of 25°c and a velocity of 30 m/s. (extternal flow ) in another case air is in fully developed flow through the tube with a temperature of 25°c and a mean velocity of 30 m/s. (internalflow ) compare the heat flux from the tube to the air for the two cases.

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.

What are the major differences between injection molding and extrusion?

Tech a says never use a water hose to clean up dust after a repair. tech b says never use a floor scrubber to clean up dust after repairs. who is correct?