Element on longitudinal strip on inside of right circular cylinder to inside of cylinder
FDiff_11(r, z, h) provides the view factor from a differential element (1) on a longitudinal strip on the inside of right circular cylinder to the entire insider surface of the cylinder (2).
Inputs:
r is the radius of the cylinder [m or ft]
z is the height of the element above the base [m or ft]
h is the height of the cylinder [m or ft]
Example:
$UnitSystem SI K Pa J deg
"The following program uses integration to calculate the view factor between the inside surface of a right circular cylinder and its base. This view factor could be found more directly using F3D_18, but use of the differential view factor allows the radiation heat transfer to be calculated even if temperature varies with axial position along the inside cylinder wall. "
r=1 [m]
h=2 [m]
F_21=integral(FDiff_11(r,z,h)*2*pi*r,z,0,h)/(2*pi*r*h)
F=F3D_18(r, h)
{Solution : F_21 = F = 0.5858}
Reference: Howell, http://www.me.utexas.edu/~howell/sectionb/B-51.html