An axi-symmetric infinite element for transient radial flow problems

The formulation of an axi-symmetric infinite element for transient analysis of flow problems in unbounded domain is presented. The theoretical basis a s well as the implementation of the element is discussed, and the element d ecay function is derived using the analytical solution of a one-dimensional axially symmetric configuration. The form of decay within the element is d escribed as a function of both time and space, and thus the hydraulic head distribution in the far field is simulated rigorously. The accuracy and the efficiency of the proposed element are demonstrated through several numeri cal examples in infinite media. In general, it is shown that using the pres ent infinite element transient flow problems in unbounded domains can be si mulated effectively. Copyright (C) 1999 John Wiley & Sons, Ltd.