Engineering, 24.09.2020 22:01 anthonysutton82

The wind chill, which is experienced on a cold, windy day, is related to increased heat transfer from exposed human skin to the surrounding atmosphere. Consider a layer of fatty tissue that is 3 mm thick and whose interior surface is maintained at a temperature of 36 C. On a calm day the convection heat transfer coefficient at the outer surface is 25 W/m2.K, but with 30 km/h winds it reaches 65 W/m2.K. In both cases the ambient air temperature is 15 C. A) What is the ratio of the heat loss perunit area from the skin for the calm day to that for the windyday?
B) What will be the skin outer surfacetemperature for the calm day? For the windy day?
C) What temperature would the air have toassume on the calm day to produce the same heat loss occurring withthe air temperature at -15ºC on the windy day?

Answers: 3

Show answers

Another question on Engineering

Engineering, 03.07.2019 14:10

Amass of 1.5 kg of air at 120 kpa and 24°c is contained in a gas-tight, frictionless piston-cylinder device. the air is now compressed to a final pressure of 720 kpa. during the process, heat is transferred from the air such that the temperature inside the cylinder remains constant. calculate the boundary work input during this process.

Answers: 2

Answer

Engineering, 04.07.2019 16:10

The force on a cutting tool are 2600n vertically downward and 2100 horizontal. determine the resultant force acting on the tool and the angle at which it acts.

Answers: 1

Answer

Engineering, 04.07.2019 18:10

An ideal otto cycle with air as the working fluid has a compression ratio of 8. the minimum and maximum temperatures in the cycle are 300 k and 1340 k. use constant specific heats at room temperature to determine (a) the amount of heat transferred to the air during the heat- addition kj/kg, (b) the thermal efficiency, and (c) the thermal efficiency of a carnot cycle ope limits. process, in rating between the same temperature

Answers: 2

Answer

Engineering, 04.07.2019 18:10

Atmospheric air has a temperature (dry bulb) of 80° f and a wet bulb temperature of 60° f when the barometric pressure is 14.696 psia. determine the specific humidity, grains/lb dry air. a. 11.4 c. 55.8 d. 22.5 b. 44.1

Answers: 1

Answer

You know the right answer?

The wind chill, which is experienced on a cold, windy day, is related to increased heat transfer fro...

Questions