Contributed by the Heat Transfer Division for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received by the Heat Transfer Division August 21, 2001; revision received May 8, 2002. Associate Editor: M. L. Hunt.
The solution of the unsteady heat conduction equation in a solid body is difficult because of the dependence of the temperature on the space variable(s) and time. In most situations, the solution sought is approached by establishing a distributed model consisting of a partial differential equation, the boundary conditions and an initial condition.
In general, the rate of heat conduction in a solid body absent of internal heat generation is dependent upon two resistances: the internal resistance inside the body and the surface resistance between the body surface and the surrounding fluid. Within this ample framework, there are two limiting cases of importance, case (a) negligible internal resistance and case (b)...
