A Study of Transient Heat Transfer in Long Insulated Wires

This study concerns the transient thermal response of long insulated wires, a composite cylinder configuration, in which a highly conducting inner cylinder is sheathed in an outer cylinder of an insulating material. The study examines the heat transfer in such a cylindrical configuration and determines the parameters that govern its thermal response. A study of the transient behavior under various important surface boundary conditions, particularly the constant surface heat flux circumstance, is undertaken. The dependence of the transient response of the body, in terms of the characteristic surface and conductor temperatures, of the temperature distribution across the insulation and of other important physical aspects on the boundary conditions and on the governing parameters is investigated. The governing equation and boundary conditions are generalized and the solution obtained numerically to obtain the desired flexibility required for the variation in the boundary conditions. Several important and interesting results are obtained which indicate the nature of the thermal response and also the criteria for obtaining a desired variation in the transient behavior of this frequently encountered configuration.