Radiative heat transfer is intended between the inner surfaces of two very large isothermal parallel metal plates. While the upper plate (designated as plate 1) is a black surface and is the warmer one being maintained at 727؛C, the lower plate (plate 2) is a diffuse and gray surface with an emissivity of 0.7 and is kept at 227؛C. Assume that the surfaces are sufficiently large to form a two-surface enclosure and steady state conditions to exist. Stefan Boltzmann constant is given as 5.67×10-8 W/m2K4.
The irradiation (in kW/m2) for the upper plate (plate 1) is
Reveal answer
Fill a bubble to check yourself
$\text{Now, Total energy incident upon plate 1 is,} \\
E = E_2 + (1 - \alpha) E_1 = 2480.625 + 17010 \\
\hspace{0.4cm} = 19490.625W/m^2 = 19.49kW/m^2 \cong 19.5 kW/m^2$