Element on longitudinal strip on inside of right circular cylinder to annual space at one end between concentric cylinders
FDiff_15(r1, r2, z) provides the view factor from a differential element (1) on a longitudinal strip on the inside of right circular cylinder with radius r2 to the annular space at one end (2) formed between concentric cylinders with radii r1 and r2.
Inputs:
r1 is the radius of the smaller concentric cylinder [m or ft]
r2 is the radius of the larger concentric cylinder cylinder [m or ft]
z is the height of the element above the base [m or ft]
Example:
$UnitSystem SI K Pa J deg
r1=0.2 [m]
r2=0.3 [m]
z=0.3 [m]
F=FDiff_15(r1, r2, z)
{Solution: F =0.2966}
Reference: Howell, http://www.me.utexas.edu/~howell/sectionb/B-58.html