Effects of Heat Loss and Gas Radiation on Turbulent Natural Convection in an Enclosure

Effects of Heat Loss and Gas Radiation on Turbulent Natural Convection in an Enclosure | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Effects of Heat Loss and Gas Radiation on Turbulent Natural Convection in an Enclosure Hadi Ahmadi Moghaddam, Svetlana Tkachenko, Guan Heng Yeoh, Victoria Timchenko This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6003813/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract The natural convection flow of air within a differentially heated cubic cavity (DHCC) has received considerable attention as a benchmark problem, owing to its relevance across various applications such as natural convection in solar chimneys or the natural ventilation of buildings. In this study, the Large Eddy Simulation (LES) technique was employed to scrutinize turbulent natural convection of both humid and dry air within a DHCC at a Rayleigh number of 1.58×10 9 . The choice of the WALE sub-grid scale model over the Dynamic Smagorinsky-Lilly model stems from turbulence modelling results, indicating it necessitates up to 11% fewer computational resources. This is particularly noteworthy considering the inherently time-consuming nature of LES computations. After turbulence modelling, the role of small contents of water vapor in the thermal-fluid characteristics of the buoyant flow has been appraised. It was observed that the radiative properties of water vapor affect the flow features. It intensifies the buoyancy, and especially near the hot wall, increases the velocity peak and boundary layer thickness, but decreases the turbulent activities near the cold wall. Finally, the role of boundary conditions applied on the horizontal passive walls is explored. The LES results suggest that the type of boundary condition has noticeable impacts on the mean flow features and turbulence statistics with pronounced effects in the near-wall region. Applying highly conducting walls causes heat exchanges with the external ambient which in turn intensifies the buoyancy effects, increases turbulent activities, and brings unsteadiness to the flow downstream of the passive walls. The present findings indicate that precise modelling of both the BCs and air humidity is required to accurately assess fluid flow and heat transfer, and turbulent statistics, for natural convection flows in enclosed cavities. Turbulent Natural Convection Large Eddy Simulation Differentially Heated Cubic Cavity Boundary Condition Radiation Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6003813","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":414269119,"identity":"8e47732c-8368-4b94-aad8-65c9efab2f65","order_by":0,"name":"Hadi Ahmadi Moghaddam","email":"data:image/png;base64,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","orcid":"","institution":"UNSW","correspondingAuthor":true,"prefix":"","firstName":"Hadi","middleName":"Ahmadi","lastName":"Moghaddam","suffix":""},{"id":414269120,"identity":"bf89cdc2-b028-4c96-9eef-cef09674391e","order_by":1,"name":"Svetlana Tkachenko","email":"","orcid":"","institution":"UNSW","correspondingAuthor":false,"prefix":"","firstName":"Svetlana","middleName":"","lastName":"Tkachenko","suffix":""},{"id":414269121,"identity":"7a2e5c0d-8527-48db-9eba-fe5050f6132b","order_by":2,"name":"Guan Heng Yeoh","email":"","orcid":"","institution":"UNSW","correspondingAuthor":false,"prefix":"","firstName":"Guan","middleName":"Heng","lastName":"Yeoh","suffix":""},{"id":414269122,"identity":"f3ea2a41-a575-473d-a0d7-1e81ab7a6a01","order_by":3,"name":"Victoria Timchenko","email":"","orcid":"","institution":"UNSW","correspondingAuthor":false,"prefix":"","firstName":"Victoria","middleName":"","lastName":"Timchenko","suffix":""}],"badges":[],"createdAt":"2025-02-11 05:23:28","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6003813/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6003813/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":87175364,"identity":"68665383-b4bf-4972-8742-fcef93fc6b2e","added_by":"auto","created_at":"2025-07-21 08:32:13","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2533112,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6003813/v1_covered_7afdefad-68ac-4b91-bc60-8e396f892882.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Effects of Heat Loss and Gas Radiation on Turbulent Natural Convection in an Enclosure","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Turbulent Natural Convection, Large Eddy Simulation, Differentially Heated Cubic Cavity, Boundary Condition, Radiation","lastPublishedDoi":"10.21203/rs.3.rs-6003813/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6003813/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe natural convection flow of air within a differentially heated cubic cavity (DHCC) has received considerable attention as a benchmark problem, owing to its relevance across various applications such as natural convection in solar chimneys or the natural ventilation of buildings. In this study, the Large Eddy Simulation (LES) technique was employed to scrutinize turbulent natural convection of both humid and dry air within a DHCC at a Rayleigh number of 1.58\u0026times;10\u003csup\u003e9\u003c/sup\u003e. The choice of the WALE sub-grid scale model over the Dynamic Smagorinsky-Lilly model stems from turbulence modelling results, indicating it necessitates up to 11% fewer computational resources. This is particularly noteworthy considering the inherently time-consuming nature of LES computations. After turbulence modelling, the role of small contents of water vapor in the thermal-fluid characteristics of the buoyant flow has been appraised. It was observed that the radiative properties of water vapor affect the flow features. It intensifies the buoyancy, and especially near the hot wall, increases the velocity peak and boundary layer thickness, but decreases the turbulent activities near the cold wall. Finally, the role of boundary conditions applied on the horizontal passive walls is explored. The LES results suggest that the type of boundary condition has noticeable impacts on the mean flow features and turbulence statistics with pronounced effects in the near-wall region. Applying highly conducting walls causes heat exchanges with the external ambient which in turn intensifies the buoyancy effects, increases turbulent activities, and brings unsteadiness to the flow downstream of the passive walls. The present findings indicate that precise modelling of both the BCs and air humidity is required to accurately assess fluid flow and heat transfer, and turbulent statistics, for natural convection flows in enclosed cavities.\u003c/p\u003e","manuscriptTitle":"Effects of Heat Loss and Gas Radiation on Turbulent Natural Convection in an Enclosure","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-02-13 17:59:36","doi":"10.21203/rs.3.rs-6003813/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"364f3c87-7e79-4cac-910e-590e7eabfe4a","owner":[],"postedDate":"February 13th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-07-21T08:24:05+00:00","versionOfRecord":[],"versionCreatedAt":"2025-02-13 17:59:36","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6003813","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6003813","identity":"rs-6003813","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}