Multi-layer Cylinder
Calculates the outer-wall temperature Tn of a concentric multi-layer cylinder, given the inner-wall temperature T0 and the radial heat flow Q. Up to four concentric layers may be specified; layers with zero thickness are ignored.
Layer Geometry
Each layer i has inner radius ri−1 and outer radius ri=ri−1+ti:
Ri=2πLckiln(ri/ri−1)Series Resistance
Rtotal=i=1∑NRiOuter Temperature
Tn=T0−Q⋅Rtotalwhere positive Q denotes heat flowing outward (T0>Tn). The end walls of the cylinder are assumed adiabatic; only radial conduction is considered.
Reference
Holman, J. P., Heat Transfer, 7th ed., McGraw-Hill, 1990, pp. 30–32.