Keywords: pollutant dispersion, concentration fluctuation, IEM, IECM, dispersion modelling, Lagrangian stochastic models, air pollution, air quality, macromixing models
A comparison between IECM and IEM Lagrangian models
A three-dimensional Lagrangian stochastic model to evaluate pollutant dispersion in terms of both mean and fluctuating concentration fields has been developed. The mean concentration field is predicted by using a macromixing model, while the micromixing scheme IECM (Interaction by Exchange with the Conditional Mean) is adopted to determine the moments of concentration. The results agree with experimental data and with other numerical studies found in literature. The performance of a second micromixing scheme, namely, the IEM (Interaction by Exchange with the Mean), is tested. Some inaccuracies of the IEM model are evaluated by comparison against measurements and IECM results.