LAGCARTW

Abstract

LAGCARTW (Lagrange Cartesian suite for Windows) provides a simple method for simulating and understanding diffusion using computer animations of random walk particles. The model is useful for teaching and demonstration purposes, but may also be used in an investigative mode—the suite optionally produces output files of particle positions which can be used in subsequent analysis. Current velocities (defined as a series of tidal harmonics) are defined over the model domain, and particles can be discharged from a series of outfalls, reflected or absorbed by boundaries, and allowed to decay. The program also allows a variable diffusion coefficient in the vertical plane. The input file can be altered quite easily via a separate interactive program. A series of demonstration files, used to illustrate examples of diffusion problems, are provided.