Thermal conductivity of a two-layer wall for a time-varying heat-transfer coefficient and ambient temperature

An analytical solution of the problem of the thermal conductivity of a two-layer wall is presented. The solution is obtained by using a special series expansion of the Green's function.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 18, No. 2, pp. 323–327, February, 1970.