Mixing and layering at the interface of a two-layer fluid forced by random jets

Mixing and layering at the interface of a two-layer fluid forced by random jets | 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 Mixing and layering at the interface of a two-layer fluid forced by random jets Noé Clavier, Yvan Dossmann, Romain Volk, Mickaël Bourgoin This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7753446/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 Understanding mixing at density interfaces is essential for predicting transport in stratified environmental flows. Laboratory studies have mostly relied on steady, spatially uniform forcing, whereas turbulence in nature is intermittent and heterogeneous. Here, we present experiments on a two-layer salt-stratified fluid forced by random turbulent bursts generated with a Randomly Actuated Synthetic Jet Array (RASJA). Density fields are measured with the light attenuation technique, allowing us to resolve the interface evolution. We find that the upward velocity of the interface follows a power-law dependence on the density jump, in agreement with previous oscillating-grid studies. At large density differences, the interface sharpens during mixing, consistent with the Phillips–Posmentier layering mechanism, while at smaller density jumps it broadens. Background potential energy analysis demonstrates irreversible mixing in both cases, with typical mixing efficiencies comprised between 6 % and 8 %. These results extend classical laboratory observations to a more isotropic forcing, offering new insights into the dynamics of mixing in geophysical settings. turbulence stratified flows mixing light-attenuation technique 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-7753446","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":535100801,"identity":"28601b1c-1d5c-4d52-8e05-1c9fe2c4a96f","order_by":0,"name":"Noé Clavier","email":"","orcid":"","institution":"École Normale Supérieure PSL","correspondingAuthor":false,"prefix":"","firstName":"Noé","middleName":"","lastName":"Clavier","suffix":""},{"id":535100802,"identity":"5eb13269-8ffd-4b0f-982c-c513f1d91032","order_by":1,"name":"Yvan Dossmann","email":"data:image/png;base64,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","orcid":"","institution":"University of Lorraine","correspondingAuthor":true,"prefix":"","firstName":"Yvan","middleName":"","lastName":"Dossmann","suffix":""},{"id":535100803,"identity":"114b7354-7c43-45cb-965c-8c4be32d0329","order_by":2,"name":"Romain Volk","email":"","orcid":"","institution":"École Normale Supérieure de Lyon","correspondingAuthor":false,"prefix":"","firstName":"Romain","middleName":"","lastName":"Volk","suffix":""},{"id":535100805,"identity":"a6c06be4-d540-40ce-86ba-aaf70a8c2e72","order_by":3,"name":"Mickaël Bourgoin","email":"","orcid":"","institution":"École Normale Supérieure de Lyon","correspondingAuthor":false,"prefix":"","firstName":"Mickaël","middleName":"","lastName":"Bourgoin","suffix":""}],"badges":[],"createdAt":"2025-09-30 16:23:14","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7753446/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7753446/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":94992609,"identity":"a1ed1c1a-31ef-4137-a12f-c63a68c12d56","added_by":"auto","created_at":"2025-11-03 07:21:54","extension":"json","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":5480,"visible":true,"origin":"","legend":"","description":"","filename":"21dd9a94e0884b49aa9f6790a8aae5b8.json","url":"https://assets-eu.researchsquare.com/files/rs-7753446/v1/2c426f1b0054fc67b481c3b2.json"},{"id":98431730,"identity":"1c629126-92c9-4cdf-84f0-18305d5e8710","added_by":"auto","created_at":"2025-12-17 16:48:15","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2590118,"visible":true,"origin":"","legend":"","description":"","filename":"submission.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7753446/v1_covered_6738f626-8168-41e7-886d-ea30b1b0fa19.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Mixing and layering at the interface of a two-layer fluid forced by random jets","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":"turbulence, stratified flows, mixing, light-attenuation technique","lastPublishedDoi":"10.21203/rs.3.rs-7753446/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7753446/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eUnderstanding mixing at density interfaces is essential for predicting transport in stratified environmental flows. 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