Characteristics of Heat Conduction in Two Layer Solids （Exact Solution and Its Applicable Range）

Composite slabs and cylinders have a various thermal function and character, depending on a combination of two materials. For example, these work a heat reservoir, a storage tank for hydrogen and make a rapid temperature change of other material slow using a thin insulation layer of Teflon and oxide as heat shock absorber. In analyzing unsteady heat conduction in these materials, one has to choose a suitable analyzing method, depending on their thermal properties and geometric dimensions and a time range dealing with these temperature change. The correctly adopted boundary conditions may make analysis and calculation for these temperature change ease. The present paper shows some examples encountered in the third type boundary condition and explains their analytical procedure and exact solution.