Afluid (rho = 1000 kg/m3 , μ = 1.4 × 10 −3 kg/m·s, cp = 4.2 kj/kg·k, and k = 0.58 w/m·k) flows with an average velocity of 0.3 m/s through a 14- m-long tube with inside diameter of 0.01 m. heat is uniformly added to the entire tube at the rate of 1500 w/m2 . determine (a) the value of convection heat transfer coefficient at the exit, (b) the value of ts − tm, and (c) the value of te − ti .

The mass flow rate of the fluid remains constant in all steady flow process. a)- true b)- false

Steel is coated with a thin layer of ceramic to protect against corrosion. what do you expect to happen to the coating when the temperature of the steel is increased significantly? explain.

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?