An air-standard dual cycle has a compression ratio of 16. At the beginning of compression, p1 = 14.5 lbf/in.2, V1 = 0.6 ft3, and T1 = 500 °R. The pressure doubles during the constant-volume heat addition process. For a maximum cycle temperature of 4000 °R, determine (a) the heat added to the cycle, in Btu, (b) the net work of the cycle, in Btu, (c) the thermal efficiency, and (d) the mean effective pressure, in lbf/in.2.

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?

Different types of steels contain different elements that alter the characteristics of the steel. for each of the following elements, explain what the element does when alloyed with steel.