Diffusion in hollow cylinders for some boundary conditions: I. Mathematical treatment

By development of the method of Carslaw and Jaeger, a general mathematical analysis for diffusion in a hollow cylinder has been given. The analysis relates to flow of mass or heat in hollow cylinders with different outer/inner radius ratio, including steady, set up transient, and decay transient states. Under the condition where diffusion coefficient is constant, the concentration profiles, and flux curves indicated in general equations for some cases have been demonstrated and discussed. A few of these novel equations, which can be applied for measuring the diffusivity and the concentration profile of hydrogen in pipeline during the electrochemical permeation test, have been presented.