In cold climates, weather reports usually give both the actual air temperature and the "wind-chill" temperature, which can be interpreted as follows. At the prevailing wind speed there is a rate of heat loss per unit area q, from a clothed person for an air temperature Te. The wind-chill temperature Twe is the air temperature that will give the same rate of heat loss on a calm day. Estimate the wind-chill temperature on a day when the air temperature is -10°C and the wind speed is 10m/s, giving a convective heat transfer coefficient of 50 W/m² K. A radiation heat transfer coefficient of 5 W/m² K can be used, and under calm conditions the convective heat transfer coefficient can be taken to be 5.0 W/m² K. Assume a 3 mm layer of skin (k = 0.35 W/m K), clothing equivalent to 8 mm-thick wool (k = 0.05 W/m K), and a temperature of 35°C below the skin. Also calculate the skin outer temperature.

In cold climates, weather reports usually give both the actual air temperature and the "wind-chill" temperature, which can be interpreted as follows. At the prevailing wind speed there is a rate of heat loss per unit area q, from a clothed person for an air temperature Te. The wind-chill temperature Twe is the air temperature that will give the same rate of heat loss on a calm day. Estimate the wind-chill temperature on a day when the air temperature is -10°C and the wind speed is 10m/s, giving a convective heat transfer coefficient of 50 W/m² K. A radiation heat transfer coefficient of 5 W/m² K can be used, and under calm conditions the convective heat transfer coefficient can be taken to be 5.0 W/m² K. Assume a 3 mm layer of skin (k = 0.35 W/m K), clothing equivalent to 8 mm-thick wool (k = 0.05 W/m K), and a temperature of 35°C below the skin. Also calculate the skin outer temperature.

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter5: Analysis Of Convection Heat Transfer

Section: Chapter Questions

Problem 5.40P

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