Concentric cylinders
Function F3D_4(r_1, r_2, w) calculates a radiation view factor between two concentric cylinders of the same finite length. F3D_4 is the view factor from the smaller of two concentric cylinders (1) to the larger cylinder (2).
Inputs:
r_1- radius of the smaller cylinder [m or ft]
r_2 - radius of the larger cylinder [m or ft]
w - length of the cylinders [m or ft]
Example:
$UnitSystem SI K Pa J deg
r_1=0.1 [m]
r_2=0.2 [m]
w=0.5 [m]
F=F3D_4(r_1, r_2, w)
{Solution: F=0.8589 }
Reference: Siegel and Howell, Thermal radiation heat transfer, 4th edition, p.847.