Air at 20°c (1 atm) enters into a 5-mm-diameter and 10-cm long circular tube at an average velocity of 5.4 m/s. the tube wall is maintained at a constant surface temperature of 160°c. determine the convection heat transfer coefficient and the outlet mean temperature. evaluate the air properties at 50°c. the properties of air at 50°c.

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?

Water at 55c flows across a flat plate whose surface temperature is held constant at 95c. if the temperature gradient at the plate's surface for a given value of x is 18 c/mm, find a) local heat transfer coefficient. b) heat flux

Draw the engineering stress-strain curve for (a) bcc; (b) fcc metals and mark important points.