The dynamics of concentration fluctuations within passive scalar plumes in a turbulent neutral boundary layer
We investigate the concentration fluctuations of passive scalar plumes emitted from small, localised (point-like) steady sources in a neutrally stratified turbulent boundary layer over a rough wall. The study utilises high-resolution large-eddy simulations for sources of varying sizes and heights. T...
Gespeichert in:
Veröffentlicht in: | Journal of fluid mechanics 2024-12, Vol.1001 |
---|---|
Hauptverfasser: | , , , , , , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
container_end_page | |
---|---|
container_issue | |
container_start_page | |
container_title | Journal of fluid mechanics |
container_volume | 1001 |
creator | Cassiani, M. Ardeshiri, H. Pisso, I. Salizzoni, P. Marro, M. Stohl, A. Stebel, K. Park, S. Y. |
description | We investigate the concentration fluctuations of passive scalar plumes emitted from small, localised (point-like) steady sources in a neutrally stratified turbulent boundary layer over a rough wall. The study utilises high-resolution large-eddy simulations for sources of varying sizes and heights. The numerical results, which show good agreement with wind-tunnel studies, are used to estimate statistical indicators of the concentration field, including spectra and moments up to the fourth order. These allow us to elucidate the mechanisms responsible for the production, transport and dissipation of concentration fluctuations, with a focus on the very near field, where the skewness is found to have negative values – an aspect not previously highlighted. The gamma probability density function is confirmed to be a robust model for the one-point concentration at sufficiently large distances from the source. However, for ground-level releases in a well-defined area around the plume centreline, the Gaussian distribution is found to be a better statistical model. As recently demonstrated by laboratory results, for elevated releases, the peak and shape of the pre-multiplied scalar spectra are confirmed to be independent of the crosswind location for a given downwind distance. Using a stochastic model and theoretical arguments, we demonstrate that this is due to the concentration spectra being directly shaped by the transverse and vertical velocity components governing the meandering of the plume. Finally, we investigate the intermittency factor, i.e. the probability of non-zero concentration, and analyse its variability depending on the thresholds adopted for its definition. |
doi_str_mv | 10.1017/jfm.2024.861 |
format | Article |
fullrecord | <record><control><sourceid>proquest_cambr</sourceid><recordid>TN_cdi_proquest_journals_3142117809</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><cupid>10_1017_jfm_2024_861</cupid><sourcerecordid>3142117809</sourcerecordid><originalsourceid>FETCH-LOGICAL-c190t-522f429f139b21c8e0725a6852cf5f5c1fe38b9497d6581cfb71afe76bac04433</originalsourceid><addsrcrecordid>eNpFkE1LxDAQhoMouK7e_AEBz62ZNG2aoyx-wYKX9VySNHG7pOmaD2X_vV1X8DQD87zvwIPQLZASCPD7nR1LSigr2wbO0AJYIwresPocLQihtACg5BJdxbgjBCoi-AKNm63B_cHLcdARTxbryWvjU5BpmDy2LuuUf_eIv4e0HTzeyxiHL4Ojlk4GvHd5NBHPB4lTDiq7OY69yXOHw2rKvpfhgJ08mHCNLqx00dz8zSV6f3rcrF6K9dvz6-phXWgQJBU1pZZRYaESioJuDeG0lk1bU21rW2uwpmqVYIL3Td2CtoqDtIY3SmrCWFUt0d2pdx-mz2xi6nZTDn5-2VXAKABviZip8kRpOaow9B_mHwPSHZV2s9LuqLSblVY_i39roQ</addsrcrecordid><sourcetype>Aggregation Database</sourcetype><iscdi>true</iscdi><recordtype>article</recordtype><pqid>3142117809</pqid></control><display><type>article</type><title>The dynamics of concentration fluctuations within passive scalar plumes in a turbulent neutral boundary layer</title><source>Cambridge Journals</source><creator>Cassiani, M. ; Ardeshiri, H. ; Pisso, I. ; Salizzoni, P. ; Marro, M. ; Stohl, A. ; Stebel, K. ; Park, S. Y.</creator><creatorcontrib>Cassiani, M. ; Ardeshiri, H. ; Pisso, I. ; Salizzoni, P. ; Marro, M. ; Stohl, A. ; Stebel, K. ; Park, S. Y.</creatorcontrib><description>We investigate the concentration fluctuations of passive scalar plumes emitted from small, localised (point-like) steady sources in a neutrally stratified turbulent boundary layer over a rough wall. The study utilises high-resolution large-eddy simulations for sources of varying sizes and heights. The numerical results, which show good agreement with wind-tunnel studies, are used to estimate statistical indicators of the concentration field, including spectra and moments up to the fourth order. These allow us to elucidate the mechanisms responsible for the production, transport and dissipation of concentration fluctuations, with a focus on the very near field, where the skewness is found to have negative values – an aspect not previously highlighted. The gamma probability density function is confirmed to be a robust model for the one-point concentration at sufficiently large distances from the source. However, for ground-level releases in a well-defined area around the plume centreline, the Gaussian distribution is found to be a better statistical model. As recently demonstrated by laboratory results, for elevated releases, the peak and shape of the pre-multiplied scalar spectra are confirmed to be independent of the crosswind location for a given downwind distance. Using a stochastic model and theoretical arguments, we demonstrate that this is due to the concentration spectra being directly shaped by the transverse and vertical velocity components governing the meandering of the plume. Finally, we investigate the intermittency factor, i.e. the probability of non-zero concentration, and analyse its variability depending on the thresholds adopted for its definition.</description><identifier>ISSN: 0022-1120</identifier><identifier>EISSN: 1469-7645</identifier><identifier>DOI: 10.1017/jfm.2024.861</identifier><language>eng</language><publisher>Cambridge, UK: Cambridge University Press</publisher><subject>Boundary layers ; Charting the Course for the Next Decade of Sustainability Research and Innovation ; Crosswinds ; Fluctuations ; Gaussian distribution ; Investigations ; JFM Papers ; Laboratories ; Large eddy simulation ; Meandering ; Normal distribution ; Oceanic eddies ; Plumes ; Probability density functions ; Reynolds number ; Skewness ; Spectra ; Statistical analysis ; Statistical models ; Stochastic models ; Stochasticity ; Time series ; Turbulent boundary layer ; Viscosity ; Wind tunnels</subject><ispartof>Journal of fluid mechanics, 2024-12, Vol.1001</ispartof><rights>The Author(s), 2024. Published by Cambridge University Press.</rights><rights>The Author(s), 2024. Published by Cambridge University Press. This work is licensed under the Creative Commons Attribution License This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0), which permits unrestricted re-use, distribution and reproduction, provided the original article is properly cited. (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.</rights><lds50>peer_reviewed</lds50><oa>free_for_read</oa><woscitedreferencessubscribed>false</woscitedreferencessubscribed><orcidid>0000-0002-6935-7564 ; 0000-0003-1625-629X ; 0000-0001-5987-9839</orcidid></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Tsyndetics_thumb_exl</thumbnail><linktohtml>$$Uhttps://www.cambridge.org/core/product/identifier/S0022112024008619/type/journal_article$$EHTML$$P50$$Gcambridge$$Hfree_for_read</linktohtml><link.rule.ids>164,314,780,784,27924,27925,55628</link.rule.ids></links><search><creatorcontrib>Cassiani, M.</creatorcontrib><creatorcontrib>Ardeshiri, H.</creatorcontrib><creatorcontrib>Pisso, I.</creatorcontrib><creatorcontrib>Salizzoni, P.</creatorcontrib><creatorcontrib>Marro, M.</creatorcontrib><creatorcontrib>Stohl, A.</creatorcontrib><creatorcontrib>Stebel, K.</creatorcontrib><creatorcontrib>Park, S. Y.</creatorcontrib><title>The dynamics of concentration fluctuations within passive scalar plumes in a turbulent neutral boundary layer</title><title>Journal of fluid mechanics</title><addtitle>J. Fluid Mech</addtitle><description>We investigate the concentration fluctuations of passive scalar plumes emitted from small, localised (point-like) steady sources in a neutrally stratified turbulent boundary layer over a rough wall. The study utilises high-resolution large-eddy simulations for sources of varying sizes and heights. The numerical results, which show good agreement with wind-tunnel studies, are used to estimate statistical indicators of the concentration field, including spectra and moments up to the fourth order. These allow us to elucidate the mechanisms responsible for the production, transport and dissipation of concentration fluctuations, with a focus on the very near field, where the skewness is found to have negative values – an aspect not previously highlighted. The gamma probability density function is confirmed to be a robust model for the one-point concentration at sufficiently large distances from the source. However, for ground-level releases in a well-defined area around the plume centreline, the Gaussian distribution is found to be a better statistical model. As recently demonstrated by laboratory results, for elevated releases, the peak and shape of the pre-multiplied scalar spectra are confirmed to be independent of the crosswind location for a given downwind distance. Using a stochastic model and theoretical arguments, we demonstrate that this is due to the concentration spectra being directly shaped by the transverse and vertical velocity components governing the meandering of the plume. Finally, we investigate the intermittency factor, i.e. the probability of non-zero concentration, and analyse its variability depending on the thresholds adopted for its definition.</description><subject>Boundary layers</subject><subject>Charting the Course for the Next Decade of Sustainability Research and Innovation</subject><subject>Crosswinds</subject><subject>Fluctuations</subject><subject>Gaussian distribution</subject><subject>Investigations</subject><subject>JFM Papers</subject><subject>Laboratories</subject><subject>Large eddy simulation</subject><subject>Meandering</subject><subject>Normal distribution</subject><subject>Oceanic eddies</subject><subject>Plumes</subject><subject>Probability density functions</subject><subject>Reynolds number</subject><subject>Skewness</subject><subject>Spectra</subject><subject>Statistical analysis</subject><subject>Statistical models</subject><subject>Stochastic models</subject><subject>Stochasticity</subject><subject>Time series</subject><subject>Turbulent boundary layer</subject><subject>Viscosity</subject><subject>Wind tunnels</subject><issn>0022-1120</issn><issn>1469-7645</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>2024</creationdate><recordtype>article</recordtype><sourceid>IKXGN</sourceid><recordid>eNpFkE1LxDAQhoMouK7e_AEBz62ZNG2aoyx-wYKX9VySNHG7pOmaD2X_vV1X8DQD87zvwIPQLZASCPD7nR1LSigr2wbO0AJYIwresPocLQihtACg5BJdxbgjBCoi-AKNm63B_cHLcdARTxbryWvjU5BpmDy2LuuUf_eIv4e0HTzeyxiHL4Ojlk4GvHd5NBHPB4lTDiq7OY69yXOHw2rKvpfhgJ08mHCNLqx00dz8zSV6f3rcrF6K9dvz6-phXWgQJBU1pZZRYaESioJuDeG0lk1bU21rW2uwpmqVYIL3Td2CtoqDtIY3SmrCWFUt0d2pdx-mz2xi6nZTDn5-2VXAKABviZip8kRpOaow9B_mHwPSHZV2s9LuqLSblVY_i39roQ</recordid><startdate>20241209</startdate><enddate>20241209</enddate><creator>Cassiani, M.</creator><creator>Ardeshiri, H.</creator><creator>Pisso, I.</creator><creator>Salizzoni, P.</creator><creator>Marro, M.</creator><creator>Stohl, A.</creator><creator>Stebel, K.</creator><creator>Park, S. Y.</creator><general>Cambridge University Press</general><scope>IKXGN</scope><scope>7TB</scope><scope>7U5</scope><scope>7UA</scope><scope>8FD</scope><scope>C1K</scope><scope>F1W</scope><scope>FR3</scope><scope>H8D</scope><scope>H96</scope><scope>KR7</scope><scope>L.G</scope><scope>L7M</scope><orcidid>https://orcid.org/0000-0002-6935-7564</orcidid><orcidid>https://orcid.org/0000-0003-1625-629X</orcidid><orcidid>https://orcid.org/0000-0001-5987-9839</orcidid></search><sort><creationdate>20241209</creationdate><title>The dynamics of concentration fluctuations within passive scalar plumes in a turbulent neutral boundary layer</title><author>Cassiani, M. ; Ardeshiri, H. ; Pisso, I. ; Salizzoni, P. ; Marro, M. ; Stohl, A. ; Stebel, K. ; Park, S. Y.</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-LOGICAL-c190t-522f429f139b21c8e0725a6852cf5f5c1fe38b9497d6581cfb71afe76bac04433</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng</language><creationdate>2024</creationdate><topic>Boundary layers</topic><topic>Charting the Course for the Next Decade of Sustainability Research and Innovation</topic><topic>Crosswinds</topic><topic>Fluctuations</topic><topic>Gaussian distribution</topic><topic>Investigations</topic><topic>JFM Papers</topic><topic>Laboratories</topic><topic>Large eddy simulation</topic><topic>Meandering</topic><topic>Normal distribution</topic><topic>Oceanic eddies</topic><topic>Plumes</topic><topic>Probability density functions</topic><topic>Reynolds number</topic><topic>Skewness</topic><topic>Spectra</topic><topic>Statistical analysis</topic><topic>Statistical models</topic><topic>Stochastic models</topic><topic>Stochasticity</topic><topic>Time series</topic><topic>Turbulent boundary layer</topic><topic>Viscosity</topic><topic>Wind tunnels</topic><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>Cassiani, M.</creatorcontrib><creatorcontrib>Ardeshiri, H.</creatorcontrib><creatorcontrib>Pisso, I.</creatorcontrib><creatorcontrib>Salizzoni, P.</creatorcontrib><creatorcontrib>Marro, M.</creatorcontrib><creatorcontrib>Stohl, A.</creatorcontrib><creatorcontrib>Stebel, K.</creatorcontrib><creatorcontrib>Park, S. Y.</creatorcontrib><collection>Cambridge Journals Open Access</collection><collection>Mechanical & Transportation Engineering Abstracts</collection><collection>Solid State and Superconductivity Abstracts</collection><collection>Water Resources Abstracts</collection><collection>Technology Research Database</collection><collection>Environmental Sciences and Pollution Management</collection><collection>ASFA: Aquatic Sciences and Fisheries Abstracts</collection><collection>Engineering Research Database</collection><collection>Aerospace Database</collection><collection>Aquatic Science & Fisheries Abstracts (ASFA) 2: Ocean Technology, Policy & Non-Living Resources</collection><collection>Civil Engineering Abstracts</collection><collection>Aquatic Science & Fisheries Abstracts (ASFA) Professional</collection><collection>Advanced Technologies Database with Aerospace</collection><jtitle>Journal of fluid mechanics</jtitle></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext</fulltext></delivery><addata><au>Cassiani, M.</au><au>Ardeshiri, H.</au><au>Pisso, I.</au><au>Salizzoni, P.</au><au>Marro, M.</au><au>Stohl, A.</au><au>Stebel, K.</au><au>Park, S. Y.</au><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>The dynamics of concentration fluctuations within passive scalar plumes in a turbulent neutral boundary layer</atitle><jtitle>Journal of fluid mechanics</jtitle><addtitle>J. Fluid Mech</addtitle><date>2024-12-09</date><risdate>2024</risdate><volume>1001</volume><issn>0022-1120</issn><eissn>1469-7645</eissn><abstract>We investigate the concentration fluctuations of passive scalar plumes emitted from small, localised (point-like) steady sources in a neutrally stratified turbulent boundary layer over a rough wall. The study utilises high-resolution large-eddy simulations for sources of varying sizes and heights. The numerical results, which show good agreement with wind-tunnel studies, are used to estimate statistical indicators of the concentration field, including spectra and moments up to the fourth order. These allow us to elucidate the mechanisms responsible for the production, transport and dissipation of concentration fluctuations, with a focus on the very near field, where the skewness is found to have negative values – an aspect not previously highlighted. The gamma probability density function is confirmed to be a robust model for the one-point concentration at sufficiently large distances from the source. However, for ground-level releases in a well-defined area around the plume centreline, the Gaussian distribution is found to be a better statistical model. As recently demonstrated by laboratory results, for elevated releases, the peak and shape of the pre-multiplied scalar spectra are confirmed to be independent of the crosswind location for a given downwind distance. Using a stochastic model and theoretical arguments, we demonstrate that this is due to the concentration spectra being directly shaped by the transverse and vertical velocity components governing the meandering of the plume. Finally, we investigate the intermittency factor, i.e. the probability of non-zero concentration, and analyse its variability depending on the thresholds adopted for its definition.</abstract><cop>Cambridge, UK</cop><pub>Cambridge University Press</pub><doi>10.1017/jfm.2024.861</doi><tpages>39</tpages><orcidid>https://orcid.org/0000-0002-6935-7564</orcidid><orcidid>https://orcid.org/0000-0003-1625-629X</orcidid><orcidid>https://orcid.org/0000-0001-5987-9839</orcidid><oa>free_for_read</oa></addata></record> |
fulltext | fulltext |
identifier | ISSN: 0022-1120 |
ispartof | Journal of fluid mechanics, 2024-12, Vol.1001 |
issn | 0022-1120 1469-7645 |
language | eng |
recordid | cdi_proquest_journals_3142117809 |
source | Cambridge Journals |
subjects | Boundary layers Charting the Course for the Next Decade of Sustainability Research and Innovation Crosswinds Fluctuations Gaussian distribution Investigations JFM Papers Laboratories Large eddy simulation Meandering Normal distribution Oceanic eddies Plumes Probability density functions Reynolds number Skewness Spectra Statistical analysis Statistical models Stochastic models Stochasticity Time series Turbulent boundary layer Viscosity Wind tunnels |
title | The dynamics of concentration fluctuations within passive scalar plumes in a turbulent neutral boundary layer |
url | https://sfx.bib-bvb.de/sfx_tum?ctx_ver=Z39.88-2004&ctx_enc=info:ofi/enc:UTF-8&ctx_tim=2024-12-25T16%3A38%3A31IST&url_ver=Z39.88-2004&url_ctx_fmt=infofi/fmt:kev:mtx:ctx&rfr_id=info:sid/primo.exlibrisgroup.com:primo3-Article-proquest_cambr&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=The%20dynamics%20of%20concentration%20fluctuations%20within%20passive%20scalar%20plumes%20in%20a%20turbulent%20neutral%20boundary%20layer&rft.jtitle=Journal%20of%20fluid%20mechanics&rft.au=Cassiani,%20M.&rft.date=2024-12-09&rft.volume=1001&rft.issn=0022-1120&rft.eissn=1469-7645&rft_id=info:doi/10.1017/jfm.2024.861&rft_dat=%3Cproquest_cambr%3E3142117809%3C/proquest_cambr%3E%3Curl%3E%3C/url%3E&disable_directlink=true&sfx.directlink=off&sfx.report_link=0&rft_id=info:oai/&rft_pqid=3142117809&rft_id=info:pmid/&rft_cupid=10_1017_jfm_2024_861&rfr_iscdi=true |