A 4.8-liter, spark-ignition, four-stroke cycle, V8 industrial engine operates 24 hours per day for five days at 2000 RPM using gasoline with A/F- 14.6. The engine has a volumetric efficiency of 92%, a brake fuel conversion efficiency of 30%, and a bore / stroke relationship as B- 1.06S. Assuming the intake temperature and pressure are 300K and 100 kPa, respectively, calculate: as B- pressure are 300K and 100 a. Stroke length (cm). b. Average piston speed (m/s). c. Number of times each spark plug has fired. d. Mass flow rate of air into engine. e. Mass flow rate of fuel into the engine f. Brake power of the engine g. Brake torque 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?