Sensitivity analysis of a concentration fluctuation model to dissipation rate estimates

Lagrangian dispersion models require estimates of the local dissipation rate (epsilon) of turbulent kinetic energy (k). In this study, we evaluate the sensitivity of a Lagrangian model to different estimates of e in simulating passive scalar dispersion in a turbulent boundary layer over a rough surface. Two different estimates of epsilon 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 epsilon.