Humans are able to control their heat production rate and heat loss rate to maintain a nearly constant core temperature
Posted: Fri Mar 04, 2022 10:10 am
Humans are able to control their heat production rate and heat
loss rate to maintain a nearly constant core temperature of 𝑇𝑐 = 37
𝑜𝐶 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, 𝑇𝑖=35
𝑜𝐶 = 308𝐾. 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 𝐴 = 1.8𝑚2 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 𝜀 = 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
loss rate to maintain a nearly constant core temperature of 𝑇𝑐 = 37
𝑜𝐶 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, 𝑇𝑖=35
𝑜𝐶 = 308𝐾. 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 𝐴 = 1.8𝑚2 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 𝜀 = 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