Modelling of heat addition to near-critical and supercritical fluids

Modelling of heat addition to near-critical and supercritical fluids | 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 Article Modelling of heat addition to near-critical and supercritical fluids Grazia Lamanna, Christoph Steinhausen This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7321148/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 26 Dec, 2025 Read the published version in Scientific Reports → Version 1 posted 17 You are reading this latest preprint version Abstract This work presents a coupled flow model to describe heat addition to near-critical and supercritical fluids. In a first approximation only forced convection is considered, while buoyancy forces, viscous and volume expansion losses are neglected. The steady, one-dimensional balance equations are solved simultaneously through an iterative procedure, taking into account real gas effects. The analysis shows that the intrinsic high compressibility of near-critical fluids, mirrored in the high peaks of the thermodynamic response functions, strongly reduces the region of validity for the incompressible flow assumption. Indeed, depending on the initial conditions, compressible flow effects may occur at Mach numbers below 0.1. For a given mass flow rate, the occurrence of heat transfer deterioration (HTD) correlates directly with the maximum amount of heat that a compressible flow can absorb. The latter is a rapid decreasing function of the local Mach number, which increases upon heat addition due the combined effect of thermal acceleration and enhanced fluid compressibility. The coupled approach also provides a natural explanation for the empirically observed dependence of HTD upon the heat flux to mass flux ratio as well as upon the ratio between the isobaric thermal expansion coefficient and the isobaric specific heat capacity. Physical sciences/Engineering Physical sciences/Mathematics and computing Physical sciences/Physics Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 26 Dec, 2025 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 02 Sep, 2025 Reviews received at journal 02 Sep, 2025 Reviews received at journal 01 Sep, 2025 Reviewers agreed at journal 01 Sep, 2025 Reviewers agreed at journal 01 Sep, 2025 Reviews received at journal 26 Aug, 2025 Reviewers agreed at journal 21 Aug, 2025 Reviewers agreed at journal 21 Aug, 2025 Reviewers agreed at journal 19 Aug, 2025 Reviewers agreed at journal 19 Aug, 2025 Reviewers agreed at journal 19 Aug, 2025 Reviewers agreed at journal 19 Aug, 2025 Reviewers invited by journal 19 Aug, 2025 Editor assigned by journal 19 Aug, 2025 Editor invited by journal 19 Aug, 2025 Submission checks completed at journal 15 Aug, 2025 First submitted to journal 15 Aug, 2025 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. 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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-7321148","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":505716152,"identity":"a31b2b76-547e-43d9-9da8-087f88abf119","order_by":0,"name":"Grazia Lamanna","email":"data:image/png;base64,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","orcid":"","institution":"University of Stuttgart","correspondingAuthor":true,"prefix":"","firstName":"Grazia","middleName":"","lastName":"Lamanna","suffix":""},{"id":505716153,"identity":"2b502914-53af-489e-ad9e-892890bfbc6e","order_by":1,"name":"Christoph Steinhausen","email":"","orcid":"","institution":"University of Stuttgart","correspondingAuthor":false,"prefix":"","firstName":"Christoph","middleName":"","lastName":"Steinhausen","suffix":""}],"badges":[],"createdAt":"2025-08-07 17:53:11","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7321148/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7321148/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41598-025-32459-z","type":"published","date":"2025-12-26T15:57:42+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":99172484,"identity":"e5dcabdc-a4f3-4ce7-b245-c1a08808bc85","added_by":"auto","created_at":"2025-12-29 16:10:24","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":8511601,"visible":true,"origin":"","legend":"","description":"","filename":"HTDmanuscriptLamannav1.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7321148/v1_covered_a6a4805d-5676-43f9-8615-ce9a6554d8fc.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Modelling of heat addition to near-critical and supercritical fluids","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":true,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-7321148/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7321148/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"This work presents a coupled flow model to describe heat addition to near-critical and supercritical fluids. 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