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Which of the followings is a wrong statement?
The shape factor is equal to one
For a flat or convex surface, the shape factor with respect to itself is zero. This aspect stems from the fact that for any part of flat or convex surface, one cannot see any other part of the same surface.
Establish a relation for the shape factor of cylindrical cavity with respect to itself of depth h and diameter d. The cavity is closed on its outer surface with a flat plate
F _{11} + F_{ 12} = 1 and F _{21} + F_{ 22} = 1. But F_{ 22} = 0, so F _{11} = 1 – A _{2 }/ A _{1}.
The reciprocity theorem states that
Where symbols have their usual meanings
It indicates the net radiation exchange can be calculated by computing one way configuration factor from either surface to the other.
Two radiating surface A _{1} = 6 m^{2} and A _{2} = 4 m^{2} have shape factor F _{12} = 0.1. Then the shape factor F _{21} will be
A _{1 }F _{12 }= A_{ 2} F _{21}.
What is the value of shape factor for two infinite parallel surfaces separated by a distance x?
All the radiation emitted by one falls on the other so shape factor is unity.
What is the shape factor of a sphere of diameter d inside a cubical box of length l = d?
F _{11} + F_{ 12} = 1 or F _{12} = 1. So, F _{21 }= π/6.
What is the shape factor of hemispherical surface closed by a plane surface of diameter d?
F _{11} + F_{ 12} = 1 and F _{21} = 1. Therefore, F _{11} = 0.5.
What is the shape factor of hemispherical surface closed by a plane surface of diameter d?
F _{11} + F_{ 12} = 1 and F _{21} = 1. Therefore, F _{11} = 0.5.
Establish a relation for shape factor for a conical cavity with respect to itself of depth h and diameter d. The cavity is closed on its outer surface with a flat plate
F _{11} = 1 – A _{2 }/ A _{1} = 1 – 2 sin α = 1 – d/ (4 h ^{2} + d ^{2}) ^{½}.
What is the shape factor for a hemispherical bowl with respect to itself of diameter d? The cavity is closed on its outer surface with a flat plate
F _{11} = 1 – A _{2 }/ A _{1 }= 0.5.
Consider a system of concentric spheres of radius r_{ 1} and r_{ 2} (r_{ 2} is greater than r_{ 1}). If r_{ 1} = 5 cm, determine the radius r_{ 2} if it is desired to have the value of shape factor F _{21} equal to 0.6
From reciprocity theorem, A _{1 }F _{12 }= A_{ 2} F _{21}.
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