Impact of Wind Direction on Flow and Turbulent Statistics Over a Realistic Urban Area: A Large-Eddy Simulation Study

Impact of Wind Direction on Flow and Turbulent Statistics Over a Realistic Urban Area: A Large-Eddy Simulation Study | 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 Impact of Wind Direction on Flow and Turbulent Statistics Over a Realistic Urban Area: A Large-Eddy Simulation Study Josep Maria Duró, Ernest Mestres, Ming Teng, Oriol Lehmkuhl, Ivette Rodriguez This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8894476/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 9 You are reading this latest preprint version Abstract We conducted high resolution large eddy simulations of the atmospheric boundary layer over the Zona Universitària Pedralbes district in Barcelona to investigate the impact of wind direction on flow and turbulence statistics within a realistic urban canopy. The computational mesh employs fourth-order spectral elements, yielding pedestrian level resolutions of approximately 1 m and total grid sizes about 500 million degrees of freedom. Sixteen wind directions uniformly distributed over 360$^\circ$ are simulated to capture the full directional response of the urban fabric. At pedestrian level, the flow exhibits extreme directional sensitivity where moderate rotation of the incoming wind reorganises the dominant flow pathways, shifting from continuous accelerated corridors when winds align with major street axes to fragmented cellular patterns under oblique inflows. These directionally activated channeling corridors govern local ventilation and sheltering. Yet, despite this pronounced local variability, double averaged vertical profiles of mean velocity and turbulence intensity collapse remarkably across all wind directions. Two distinct inflection points are consistently identified in the mean velocity profiles: one located slightly below the average building height, confirming the persistence of a shear driven mixing layer regime even in highly heterogeneous urban morphology, and a second, deeper inflection point near pedestrian level ($z/H_{avg} = 0.08-0.10$)that marks the transition between recirculating near ground flow and more connected intra canopy transport. Turbulence intensity maxima are systematically located between the mean and maximum building heights, implicating the tallest structures as the dominant generators of turbulent kinetic energy through wake shedding and roof edge shear. It is shown that urban aerodynamic response is simultaneously robust at the neighbourhood scale, behaving quasi isotropically in the double averaged sense, and strongly directional at the local scale, where the activation of preferential ventilation pathways dictates the spatial distribution of momentum and turbulence. large-eddy simulation urban canopy flow wind direction pedestrian-level wind double-averaging turbulence Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Revision Version 1 posted Editorial decision: Revision requested 16 May, 2026 Reviews received at journal 16 May, 2026 Reviews received at journal 18 Mar, 2026 Reviewers agreed at journal 11 Mar, 2026 Reviewers agreed at journal 26 Feb, 2026 Reviewers invited by journal 24 Feb, 2026 Editor assigned by journal 18 Feb, 2026 Submission checks completed at journal 18 Feb, 2026 First submitted to journal 16 Feb, 2026 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. 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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-8894476","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":597104965,"identity":"42310e72-85ca-4fa5-b0e0-605f80c00d13","order_by":0,"name":"Josep Maria Duró","email":"","orcid":"","institution":"Universitat Politècnica de Catalunya","correspondingAuthor":false,"prefix":"","firstName":"Josep","middleName":"Maria","lastName":"Duró","suffix":""},{"id":597104966,"identity":"60e21c7d-eb57-4aa9-88df-db3e52ff78e5","order_by":1,"name":"Ernest Mestres","email":"","orcid":"","institution":"Universitat Politècnica de Catalunya","correspondingAuthor":false,"prefix":"","firstName":"Ernest","middleName":"","lastName":"Mestres","suffix":""},{"id":597104967,"identity":"437f9d7b-607a-4b20-88e1-7d21473b197d","order_by":2,"name":"Ming Teng","email":"","orcid":"","institution":"Barcelona Supercomputing Center","correspondingAuthor":false,"prefix":"","firstName":"Ming","middleName":"","lastName":"Teng","suffix":""},{"id":597104968,"identity":"6fb4c287-8922-4a39-91bf-4fdcec81963c","order_by":3,"name":"Oriol Lehmkuhl","email":"","orcid":"","institution":"Barcelona Supercomputing Center","correspondingAuthor":false,"prefix":"","firstName":"Oriol","middleName":"","lastName":"Lehmkuhl","suffix":""},{"id":597104969,"identity":"b85d6832-11dd-49b1-8b40-ecc2e38a30ec","order_by":4,"name":"Ivette Rodriguez","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABAElEQVRIie3RMUvDQBTA8RcOmiWY9WUofoUrgUBpsV+lJZAuVjfJ0OGBcC75APXb3HFQl0PXjIqgmySD0KlqUq1Zkqwd7j/cuxt+cNwB2Gwn2OB/OwdZDf9wYl3EIdkkAfUQaJI6LnvIGcYPr0UK1767elGfYjoL85UqIJ0sqO1imCxIGhjfZ+9cD0XCovwqRjDLduKZESkBnOcJ6EDoQZRfRuAI3UGeSlL7I/nywk1F9h3EzRxSdCCqFBI5VoS6iBhtzBZ5kL2BhseYo/mIcb5dhm3k/JY9F+l6yn03YeXu5mLm3/28WLGeDNvIb1ivzKuHd/yj/pzdH7HZbDZbo28SQFjikG+gRAAAAABJRU5ErkJggg==","orcid":"","institution":"Universitat Politècnica de Catalunya","correspondingAuthor":true,"prefix":"","firstName":"Ivette","middleName":"","lastName":"Rodriguez","suffix":""}],"badges":[],"createdAt":"2026-02-16 15:39:48","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8894476/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8894476/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":104398160,"identity":"86181e5b-409e-4767-8b6f-256b29d250ff","added_by":"auto","created_at":"2026-03-11 12:00:03","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":32369081,"visible":true,"origin":"","legend":"","description":"","filename":"submission.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8894476/v1_covered_b09a051c-050f-4844-961e-ea586ec79c5a.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Impact of Wind Direction on Flow and Turbulent Statistics Over a Realistic Urban Area: A Large-Eddy Simulation Study","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"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":"flow-turbulence-and-combustion","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"appl","sideBox":"Learn more about [Flow, Turbulence and Combustion](http://link.springer.com/journal/10494)","snPcode":"10494","submissionUrl":"https://submission.nature.com/new-submission/10494/3","title":"Flow, Turbulence and Combustion","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"large-eddy simulation, urban canopy flow, wind direction, pedestrian-level wind, double-averaging, turbulence","lastPublishedDoi":"10.21203/rs.3.rs-8894476/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8894476/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"We conducted high resolution large eddy simulations of the atmospheric boundary layer over the Zona Universitària Pedralbes district in Barcelona to investigate the impact of wind direction on flow and turbulence statistics within a realistic urban canopy. 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