Abstract
In this work, we propose and evaluate a one-particle Lagrangian stochastic model for the assessment of the concentration-fluctuation variance, which is often used to predict odour hours for example. The main challenge is to provide a suitable parameterisation for the concentration-variance dissipation time scale. While the particle mass is conserved along the particle trajectory, the concentration variance dissipates. The concentration variance in a Lagrangian particle model evolves according to the same Langevin equation used for the simulation of the turbulent dispersion resulting in a mean concentration field. The variance dissipation is taken into account via a decay term with a finite time scale. We herein discuss and compare different parameterisations of the variance-dissipation time scale against observations from a field experiment. It was found that best results are obtained prescribing the ratio between the concentration-variance dissipation time scale and the Lagrangian time scale, which depends on the travel time.
Lingua originale | Inglese |
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pagine (da-a) | 237-246 |
Numero di pagine | 10 |
Rivista | Atmospheric Environment |
Volume | 206 |
DOI | |
Stato di pubblicazione | Pubblicato - 1 giu 2019 |