The reciprocity relation, the summation rule, and Equations 13.5 to 13.7 can be used to develop view factor relations that allow for applications of Figure 13.4 and/or 13.6 to more complex configurations.?Consider the view factor F₁₄ for surfaces 1 and 4 of the following geometry. These surfaces are perpendicular but do not share a common edge.

(a) Obtain the following expression for the view factor F₁₄:

(b) If L₁ = L₂ = L₄ = (W/2) and L₃ = W, what is the value of F₁₄?

[(A, + A)F1234, + A;F23 A, part a - (A, + Az)F1.213 - A,F34] A L, = L,= L l3 = W = W/2 A A3 YIX= 0.02 0.5 0.05 04 0.1 0.2 0.3 0.4 0.6 02 1.0 1.5 0.1 2.0 10 20 0.1 0.2 0.4 0.6 0.8 1 8 10 ZIX 1.0 0.7 0.5 0.4 1.0 0.3 0.6- 0.2 0.2 -0.4 0.1 0.07 0.05 0.04 YIL = 0.1 0.03 0,02 0.01 0.1 0.2 0.3 0.5 2 3 45 1.0 10 20 XIL