Answer Happy

Problem 1 (20 Points) Thermal circuit analysis 1. In cold climates, the weather reports usually give the actual air temperature as well as the "wind-chill" temperature that can be interpreted as follows. At the prevailing wind speed, there is a rate of heat loss per unit area qs 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. Under calm conditions, a radiative heat transfer coefficient of 5 W/m² K can be used, and the convective heat transfer coefficient can be assumed to be 5 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/m² K) and a temperature of 35 °C below the skin. body Tb 35C 9s skin k, Windy day clothing ke Actual Temperature (T-10 C at u-10 m/s) Convection (h,= 10 W/m²K) Radiation (h,= 5 W/m²K) body skin Ть k₂ 35C qs Calm day clothing k₂ Actual Temperature (Twe= ??? at u=0) Convection (h₂=5 W/m²K) Radiation (h,= 5 W/m²K) (a) Estimate the wind chill temperature on a day where the air temperature is -10 °C and the wind speed is 10 m/s giving a convective heat transfer coefficient of 10 W/m²K. (b) Calculate the temperature of the skin's surface under the conditions described in part (a).