Humans are able to control their heat production rate and heat
loss rate to maintain a nearly constant core temperature of ππ = 37
ππΆ under a wide range of environmental conditions. This
process is called thermoregulation. From the perspective of
calculating heat transfer between a human body and its
surroundings, we focus on a layer of skin and fat, with its outer
surface exposed to the environment and its inner surface at a
temperature slightly less than the core temperature, ππ=35
ππΆ = 308πΎ. Consider a person with a skin/fat layer of
thickness L=3 mm and effective thermal conductivity k=0.3 W/(mK).
The person has a surface area π΄ = 1.8π2 and is dressed
in a bathing suit (we assume bathing suit has no effect on heat
loss from body). The emissivity of the skin is π = 0.95.
Hint:
T; = 308 K Skin/fat S !T T. II E = 0.95 grad Tsur = 297 K q"cond 9. Con k = 0.3 W/m.K = co 1 1 T = 297 K h = 2 W/m2K (Air) h = 200 W/m2.K (Water) L= 3 mm Air or water
Humans are able to control their heat production rate and heat loss rate to maintain a nearly constant core temperature
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