Two gray surfaces with emmissivities &=0.95 and 2=0.6 are located as shown in the figure. The temperature of the plate 1 T=527 K and temperature of the plate 2 is T2=827 K. Calculate the radiation heat transfer between the surfaces. Ignore the heat transfer between surfaces and the surrounding air. For an enclosure it can be written that -1 FA-A AFA-A = AjFAAi For sub-surfaces A = K-1A (j.k) k=1 in 8 Fy 90 0.5 0.4 0.3 0.2 0.1 0 A W 0.1 A YIX= 0.02 0.05 0.1 0.2 0.2 0.4 0.6 1.0 FAL-A = EK=1FA-A(1,k) Two finite rectangles of same length, having one common edge and having an angle of 90 to each other. h H = - 1.5 1 F-= 1 W 2.0 H + W tan- 0.4 0.6 0.8 1 W = 4 W ZIX 1 W tan-1. W(1+ W+ H) (1+ W)(W + H) 1 W 1 H + W 2 + H tan- 7W X Z = : 1 and 10 H (1+ H +W) (1+ H) (H +W) 1 H 1 (1+W)(1+ H) In 4 1+ W + H 4 Y 20 i X 74 6 8 10