Investigation on Hydro-Performance and Flow Structures of NACA 0009 Hydrofoil with Bionic Fish-Scale on Upper Surface

Investigation on Hydro-Performance and Flow Structures of NACA 0009 Hydrofoil with Bionic Fish-Scale on Upper Surface | 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 Investigation on Hydro-Performance and Flow Structures of NACA 0009 Hydrofoil with Bionic Fish-Scale on Upper Surface Bifeng Li, Baosheng Xie, Lei Xu, Mendi Chen, Yuchuan Wang, Lei Tan This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9513184/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 4 You are reading this latest preprint version Abstract Bio-inspired fish-scale microstructures have been proposed as a passive surface modification for hydrofoils, yet their effects on hydro-performance and near-wall flow remain unclear. To investigate this, the flow around the NACA0009 hydrofoil without and with crucian carp scales on its upper surface are investigated. Numerical simulations and orthogonal tests are conducted to reveal the influence of bionic structural parameters on the hydrofoil performance and the underlying mechanisms. The range analysis and multi-factor variance analysis indicated that the factors are ranked, from most to least significant, as groove depth, radius, and groove gap. The lift-to-drag ratio is proportional to radius and inversely proportional to groove gap and groove depth. The optimized bionic fish-scale structure achieves a lift-to-drag ratio 7.56% higher than that of the smooth surface hydrofoil. This hydrofoil performance is improved by increasing the wall-friction loss, vorticity at the trailing edge, and flow circulation, reducing the adverse pressure gradient and boundary shear layer thickness, and enhancing the pressure difference between the upper and lower surfaces. This study provides a passive circulation method for the hydrofoil flow and its applications. NACA0009 hydrofoil Bionic fish-scale microstructure Hydrofoil performance Boundary Layers Adverse pressure gradient Full Text Cite Share Download PDF Status: Under Review Version 1 posted Reviewers agreed at journal 01 May, 2026 Reviewers invited by journal 01 May, 2026 Editor assigned by journal 30 Apr, 2026 First submitted to journal 27 Apr, 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-9513184","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":632783668,"identity":"b4a588b1-231b-42ab-8aa5-eb4ee226400b","order_by":0,"name":"Bifeng 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