Lagrangian dispersion models require estimates of the local dissipation rate (ε) of turbulent kinetic energy (κ). In this study, we evaluate the sensitivity of a Lagrangian model to different estimates of ε in simulating passive scalar dispersion in a turbulent boundary layer over a rough surface. Two different estimates of ε are used to simulate pollutant dispersion emitted by a linear elevated source with a Lagrangian model which integrates a macromixing and a micromixing scheme. Comparison between numerical and experimental results allows us to discuss the performance of the model and to define its sensitivity to ε.
Keywords: LAGFLUM, air pollution, atmospheric dispersion, concentration fluctuations, Lagrangian dispersion modelling, micromixing, wind tunnel experiment, dissipation rate, sensitivity analysis, air quality, turbulent kinetic energy, turbulent boundary layers, rough surfaces