Consider a 320 mm × 320 mm window in an aircraft. for a temperature difference of 80°c from the inner to the outer surface of the window, calculate the heat loss through 10-mm-thick polycarbonate, soda lime glass, and aerogel windows, respectively. the thermal conductivities of the aerogel and polycarbonate are 0.014 w/m·k and 0.21 w/m·k, respectively. evaluate the thermal conductivity of the soda lime glass at 300 k. if the aircraft has 130 windows and the cost to heat the cabin air is $1/kw·h, compare the costs associated with the heat loss through the windows for an 8-hour intercontinental flight.

Apiston-cylinder with a volume of 0.25 m3 holds 1 kg of air (r 0.287 k/kgk) at a temperature of 100 c. heat transfer to the cylinder causes an isothermal expansion of the piston until the volume triples. how much heat is added to the piston-cylinder?

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?