Ducted Co-Rotating Rotors as an Alternative for UAV Propulsion: An Experimental Aeroacoustic Study

Ducted Co-Rotating Rotors as an Alternative for UAV Propulsion: An Experimental Aeroacoustic 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 Ducted Co-Rotating Rotors as an Alternative for UAV Propulsion: An Experimental Aeroacoustic Study Pawel Kekus-Kumor, Adam Sieradzki This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8742849/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 coaxial, co-rotating configuration of rotors, also referred to as stacked rotors, is a promising alternative to counter-rotating rotors, simpler and lighter mechanically, while still providing improved disk loading relative to an isolated rotor. Ducting, on the other hand, is commonly used on rotorcraft for improved efficiency and safety, as well as some reduction of noise emissions. In this work, the two solutions are combined. Aeroacoustic performance of ducted stacked rotors is evaluated experimentally in an anechoic chamber, and compared to similar cases of an isolated rotor, a single ducted rotor, and unducted stacked rotors. Although changes to blade geometry necessitated by the presence of a duct prevent testing of truly analogous cases, an attempt is made at a fair comparison between the different configurations. The results show similar efficiency of the ducted stacked configuration relative to a single ducted rotor, but with an apparent detriment to the acoustic performance. Compared to unducted stacked rotors, the ducted configuration provides improved efficiency and similar noise levels. Furthermore, a range of blade pitch angles, with varying increments between the upstream and downstream rotors, is tested for the ducted stacked rotors. The impact of dissimilar pitch between the rotors on the aeroacoustic performance of the system is small but distinct, with certain pitch configurations generating less noise than others. This suggests that there is significant potential in optimising rotor blades specifically for coaxial operation. Aeroacoustics UAV ducted rotors stacked rotors anechoic chamber 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. 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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-8742849","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":584909630,"identity":"978ca80b-b6db-4b1a-8c11-435c425c0647","order_by":0,"name":"Pawel Kekus-Kumor","email":"data:image/png;base64,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","orcid":"","institution":"Łukasiewicz Research Network - Institute of Aviation","correspondingAuthor":true,"prefix":"","firstName":"Pawel","middleName":"","lastName":"Kekus-Kumor","suffix":""},{"id":584909631,"identity":"183e01d7-c4db-49a1-ac27-2fbe9a294175","order_by":1,"name":"Adam Sieradzki","email":"","orcid":"","institution":"Łukasiewicz Research Network - Institute of Aviation","correspondingAuthor":false,"prefix":"","firstName":"Adam","middleName":"","lastName":"Sieradzki","suffix":""}],"badges":[],"createdAt":"2026-01-30 15:39:44","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8742849/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8742849/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":101921034,"identity":"c64c1bbe-a764-451a-9ae0-b9b1d0d7acf8","added_by":"auto","created_at":"2026-02-05 04:40:15","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":4054768,"visible":true,"origin":"","legend":"","description":"","filename":"Manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8742849/v1_covered_ea38f423-a3bc-49aa-8f9f-59ad69d90de3.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Ducted Co-Rotating Rotors as an Alternative for UAV Propulsion: An Experimental Aeroacoustic Study","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":"Aeroacoustics, UAV, ducted rotors, stacked rotors, anechoic chamber","lastPublishedDoi":"10.21203/rs.3.rs-8742849/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8742849/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe coaxial, co-rotating configuration of rotors, also referred to as stacked rotors, is a promising alternative to counter-rotating rotors, simpler and lighter mechanically, while still providing improved disk loading relative to an isolated rotor. 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