The Principal Direction Technique for Advective-Dispersive Transport Simulation in Three Dimensions

The Principal Direction Technique for advection-dispersion problems is extended to three dimensions. The technique combines the versatility of Galerkin finite elements in handling non-rectangular domains with the efficiency and conceptual simplicity of an alternating direction time-stepping scheme. Various time step splitting options are explored. The resulting algorithm appears to have both the accuracy and the efficiency necessary for routine application to 3-D problems of practical significance.