The plate in Problem 3.33 gradually oxidizes over time so that the surface emissivity increases to 0.5. Calculate the resulting temperature in the plate including radiation heat transfer to the surroundings at the same temperature as the ambient temperature. From Problem 3.33: A 1-cm-thick, 1-m-square steel plate is exposed to sunlight and absorbs a solar flux of 800 W/m2. The bottom of the plate is insulated, the edges are maintained at 20°C by water-cooled clamps, and the exposed face is cooled by a convection coefficient of 10 W/(m2 K) to an ambient temperature of 10°C. The plate is polished to minimize reradiation. Determine the temperature distribution in the plate using a node spacing of 20 cm. the thermal conductivity of the steel is 40W/(m K).

GIVEN

Plate in Problem 3.33 oxidizes

ASSUMPTIONS

(a) Neglect temperature gradients through the platethickness

20C 6. 5. 20C 20C 20C