A hollow cylinder has length L, inner radius R, and thickness d, and the temperatures at the inner and outer surfaces are Tn and Ti, respectively. The thermal conductivity of the material of which the cylinder is made is k. Derive an equation for the rate of heat transfer P through the walls of the cylinder. Simplify this equation assuming that the thickness of the cylinder d is much smaller than the its inner radius R.

A hollow cylinder has length L, inner radius R, and thickness d, and the temperatures at the inner and outer surfaces are Tn and Ti, respectively. The thermal conductivity of the material of which the cylinder is made is k. Derive an equation for the rate of heat transfer P through the walls of the cylinder. Simplify this equation assuming that the thickness of the cylinder d is much smaller than the its inner radius R.