The concentration of a passive scalar dispersed in a turbulent flow exhibits a complex stochastic dynamics. In this paper, we present a minimalist stochastic model that resembles the concentration statistics of a passive scalar emitted from a localized source in a neutral boundary layer. The model provides closed forms for the crossing rates and times — the mean frequency of exceeding a certain concentration level and the mean time above it. Three concentration statistics are needed as model inputs: the mean, the standard deviation, and the integral scale. By giving analytical relationships also for these statistics, we provide a completely closed methodology that may serve as a rapid and practical tool to estimate the dynamics of a pollutant dispersed in the atmosphere. Results are validated against wind-tunnel measurements.

Level-crossing statistics of a passive scalar dispersed in a neutral boundary layer / Bertagni, Matteo B.; Marro, Massimo; Salizzoni, Pietro; Camporeale, CARLO VINCENZO. - In: ATMOSPHERIC ENVIRONMENT. - ISSN 1352-2310. - 230:(2020). [10.1016/j.atmosenv.2020.117518]

Level-crossing statistics of a passive scalar dispersed in a neutral boundary layer

Matteo B. Bertagni;Carlo Camporeale
2020

Abstract

The concentration of a passive scalar dispersed in a turbulent flow exhibits a complex stochastic dynamics. In this paper, we present a minimalist stochastic model that resembles the concentration statistics of a passive scalar emitted from a localized source in a neutral boundary layer. The model provides closed forms for the crossing rates and times — the mean frequency of exceeding a certain concentration level and the mean time above it. Three concentration statistics are needed as model inputs: the mean, the standard deviation, and the integral scale. By giving analytical relationships also for these statistics, we provide a completely closed methodology that may serve as a rapid and practical tool to estimate the dynamics of a pollutant dispersed in the atmosphere. Results are validated against wind-tunnel measurements.
File in questo prodotto:
File Dimensione Formato  
Bertagni et al 2020 Atm Env.pdf

non disponibili

Descrizione: Articolo Principale
Tipologia: 2a Post-print versione editoriale / Version of Record
Licenza: Non Pubblico - Accesso privato/ristretto
Dimensione 1.61 MB
Formato Adobe PDF
1.61 MB Adobe PDF   Visualizza/Apri   Richiedi una copia
Level-crossingBertagni-manuscript.pdf

embargo fino al 18/04/2022

Tipologia: 2. Post-print / Author's Accepted Manuscript
Licenza: Creative commons
Dimensione 1.36 MB
Formato Adobe PDF
1.36 MB Adobe PDF Visualizza/Apri
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11583/2813672