A four cylinder, four-stroke, spark ignition engine has a compression ratio of 10 and runs at 2400 rpm. Each cylinder has a bore of 7.6 cm and each piston has a stroke of 9.8 cm. The processes within each cylinder are modeled as an air-standard Otto cycle. At the beginning of the compression process (state 1), the air is at 290 K and 80 kPa. The combustion adds 1100 kJ/kg to the air. Determine:

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?

Determine whether or not it is possible to compress air adiabatically from k to 140 kpa and 400 k. what is the entropy change during this process?

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