Hybrid numerical method applied to transient hygrothermal analysis in an annular cylinder

A hybrid numerical method of the Laplace transformation and the finite difference is applied to solve the transient hygrothermal problem of an infinitely long annular cylinder, in which the temperature and moisture coupling at the inner and outer surfaces is taken into account in the boundary conditions. By a combining method of the Laplace transformation and the finite difference, the general solutions of the governing equations are first solved in the transform domain. Then the inversion to the real domain is completed by the method of matrix operation and Fourier series technique. The transient distributions of temperature, moisture, displacement, stresses of the annular cylinder in the real domain are calculated numerically. The presented method is also applicable to multiplayer annular cylinders and to other types of boundary conditions.