In: Other
Consider steady heat transfer between two large parallel plates
at
constant temperatures of T1 582 K and T2 196 K that are 6.8 cm
apart.
Assuming the surfaces to have emissivity 0.9 , determine the rate
of heat
transfer between the plates per unit surface area assuming the
gap
between the plates is
(a) filled with atmospheric air
(b) evacuated
(c) filled with fiberglass insulation, and
(d) filled with super insulation having an apparent
thermal conductivity of 0.00045 W/m · °C.
Data given:
Plastic 0.4 W/mK
brick 0.72W/m°C
plaster 0.36 W/m°C
cement 1.4 W/m°C
Polyurethane foam 0.025W/m °C
Glass fiber/fiber glass 0.036 W/m °C
Air 0.0198 W/m °C
Copper 380W/m °C
# just take the required data
This problem can be solved using the concepts of heat transfer by conduction and radiation
I explained the two concepts in the below images and solved the four parts of the question
Please give a thumbs up if you like my answer. Leave a comment if you have any doubt. Good Luck!