Complete the information in the question below: The shivering sensation, which is experienced on cold windy days, is related to the transfer of heat from exposed human skin to the surrounding atmosphere. below the skin, consider a layer of adipose tissue 3mm thick, whose inner surface is maintained at 36ºC (healthy person, no fever). Also consider that the thermal conductivity of adipose tissue is about 0.2 W/(m K). Assume that we analyze a small local element of the body, so that we can consider the geometry of the surfaces that transfer heat locally to be flat. As the skin is thin, we will initially neglect its resistance to heat transport. On a day with winds at 30 km/h, the ambient air temperature is -15oC and the convection heat transfer coefficient at the outer surface (film coefficient) is 65W/(m2 K), thus, the heat loss of the element is _____________ W/m2 and the skin surface temperature will be _____________ºC. On a windless day and maintained at an ambient temperature of -15°C, the convection heat transfer coefficient at the outer surface is 15W/(m2 K), so the heat loss in the element is _________ W/m2 and the temperature of the skin surface will be _________ºC. In short, the lowest thermal sensation occurs on __________ day [with/without] wind, because in that case we lost ___________ [less/more] heat to the environment and skin temperature is _________ [increased/decreased]
Complete the information in the question below:
The shivering sensation, which is experienced on cold windy days, is related to the transfer of heat from exposed human skin to the surrounding atmosphere. below the skin, consider a layer of adipose tissue 3mm thick, whose inner surface is maintained at 36ºC (healthy person, no fever). Also consider that the thermal conductivity of adipose tissue is about 0.2 W/(m K). Assume that we analyze a small local element of the body, so that we can consider the geometry of the surfaces that transfer heat locally to be flat. As the skin is thin, we will initially neglect its resistance to heat transport.
On a day with winds at 30 km/h, the ambient air temperature is -15oC and the convection heat transfer coefficient at the outer surface (film coefficient) is 65W/(m2 K), thus, the heat loss of the element is _____________ W/m2 and the skin surface temperature will be _____________ºC.
On a windless day and maintained at an ambient temperature of -15°C, the convection heat transfer coefficient at the outer surface is 15W/(m2 K), so the heat loss in the element is _________ W/m2 and the temperature of the skin surface will be _________ºC.
In short, the lowest thermal sensation occurs on __________ day [with/without] wind, because in that case we lost ___________ [less/more] heat to the environment and skin temperature is _________ [increased/decreased] .
Step by step
Solved in 5 steps with 1 images
