Agas turbine for an automobile is designed with a regenerator. air enters the compressor of this
engine at 100 kpa and 20°c. the compressor pressure ratio is 8; the maximum cycle temperature is
800°c; and the cold air stream leaves the regenerator 10°c cooler than the hot air stream at the inlet
of the regenerator. assuming both the compressor and the turbine to be isentropic, determine the
rates of heat addition and rejection for this cycle when it produces 150 kw. use constant specific
heats at room temperature. draw a t-s diagram of the engine

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.

The higher the astm grain-size number, the coarser the grain is. a)-true b)-false