Constructal Theory of Aerodynamic Design in NACA Airfoils with Low Reynolds Numbers for Search and Rescue UAVs: ANN and CFD Integration

Constructal Theory of Aerodynamic Design in NACA Airfoils with Low Reynolds Numbers for Search and Rescue UAVs: ANN and CFD Integration | 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 Constructal Theory of Aerodynamic Design in NACA Airfoils with Low Reynolds Numbers for Search and Rescue UAVs: ANN and CFD Integration Suhaib J. Shbailat, Hind Dhia’a Ridha This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8621481/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 11 You are reading this latest preprint version Abstract Constractal design of the NACA airfoil was to reduce the drag force and increase the lift force for search and rescue (SAR) missions. This series of NACA airfoils is defined by a 4-digit NACA mptt, which indicates the camber, the location of maximum camber, and the thickness. Three degrees of freedom can be used to optimize aircraft airfoils using constructal theory. The CFD simulation was conducted in ANSYS FLUENT version (15), and the SST k-𝜔 model turbulence equations were used to solve the incompressible Reynolds-averaged Navier-Stokes (RANS) equations. Simulations are performed using MATLAB's Neural Network ANN, which enables a robust surrogate-based algorithm for the design study. The highest Cl/Cd ratio indicates the trade-off between lift and drag. An airfoil with a high Cl/Cd ratio produces more lift than drag, thereby enhancing aerodynamic performance through comparative analysis of three degrees of freedom (m, p, t). NACA 4412 makes a better Cl/Cd ratio, 1.38 at 4°-12°, than NACA 4418, about 26% higher at the same AOA 4°-12 °. An increase in Reynolds number led to higher CL/CD ratios across all profiles, indicating higher aerodynamic efficiency. It is particularly applicable to search-and-rescue UAVs, which can operate at varying speeds and altitudes depending on mission requirements. The ANN model has determined the optimal AOA and Reynolds number that maximizes the CL/CD ratio of the NACA 4412 airfoil. Physical sciences/Engineering Physical sciences/Mathematics and computing NACA airfoils Search and Rescue UAVs Aerodynamic optimization ANN CFD Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 16 Feb, 2026 Reviews received at journal 13 Feb, 2026 Reviewers agreed at journal 04 Feb, 2026 Reviewers agreed at journal 03 Feb, 2026 Reviews received at journal 29 Jan, 2026 Reviewers agreed at journal 29 Jan, 2026 Reviewers invited by journal 28 Jan, 2026 Editor assigned by journal 28 Jan, 2026 Editor invited by journal 28 Jan, 2026 Submission checks completed at journal 26 Jan, 2026 First submitted to journal 26 Jan, 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. 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-8621481","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":587604358,"identity":"d24db7a7-1063-4a29-8346-5bed2e0ba317","order_by":0,"name":"Suhaib J. 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This series of NACA airfoils is defined by a 4-digit NACA mptt, which indicates the camber, the location of maximum camber, and the thickness. Three degrees of freedom can be used to optimize aircraft airfoils using constructal theory. The CFD simulation was conducted in ANSYS FLUENT version (15), and the SST k-𝜔 model turbulence equations were used to solve the incompressible Reynolds-averaged Navier-Stokes (RANS) equations. Simulations are performed using MATLAB's Neural Network ANN, which enables a robust surrogate-based algorithm for the design study. The highest Cl/Cd ratio indicates the trade-off between lift and drag. An airfoil with a high Cl/Cd ratio produces more lift than drag, thereby enhancing aerodynamic performance through comparative analysis of three degrees of freedom (m, p, t). NACA 4412 makes a better Cl/Cd ratio, 1.38 at 4°-12°, than NACA 4418, about 26% higher at the same AOA 4°-12 °. An increase in Reynolds number led to higher CL/CD ratios across all profiles, indicating higher aerodynamic efficiency. It is particularly applicable to search-and-rescue UAVs, which can operate at varying speeds and altitudes depending on mission requirements. The ANN model has determined the optimal AOA and Reynolds number that maximizes the CL/CD ratio of the NACA 4412 airfoil.","manuscriptTitle":"Constructal Theory of Aerodynamic Design in NACA Airfoils with Low Reynolds Numbers for Search and Rescue UAVs: ANN and CFD Integration","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-10 04:03:53","doi":"10.21203/rs.3.rs-8621481/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-02-16T07:35:53+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-14T00:39:44+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"111473840555161770421630252150196836664","date":"2026-02-04T20:52:28+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"248278853452890877205045418102096385606","date":"2026-02-03T18:12:27+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-01-29T17:07:40+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"231830232095672604981650752514197040181","date":"2026-01-29T05:40:44+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-01-29T03:47:09+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-01-29T03:45:09+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-01-28T11:47:17+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-01-26T19:11:29+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2026-01-26T19:09:43+00:00","index":"","fulltext":""}],"status":"published","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}}],"origin":"","ownerIdentity":"9775f1bf-239e-41ef-9b95-4ae66f1b644a","owner":[],"postedDate":"February 10th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":62519633,"name":"Physical sciences/Engineering"},{"id":62519634,"name":"Physical sciences/Mathematics and computing"}],"tags":[],"updatedAt":"2026-05-19T16:39:32+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-10 04:03:53","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8621481","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8621481","identity":"rs-8621481","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}