Optimization of Optical Systems for Background Oriented Schlieren

Optimization of Optical Systems for Background Oriented Schlieren | 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 Optimization of Optical Systems for Background Oriented Schlieren Tanbo Zhou, Jonathan Gaskins, Jonathan Poggie, Sally Bane This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5053181/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 Background oriented schlieren (BOS) is a non-intrusive optical method for measuring density gradients in a fluid flow based on variations of the local refractive index. The type of BOS optical system used, i.e., entocentric vs. telecentric, and the system design determine the accuracy and quality of the measurement. This work aims to optimize both types of optical systems to minimize the error for measurements of high-speed compressible turbulent boundary layers. Claims of the advantages offered by telecentric optical systems over entocentric systems are investigated, as well as the out-of-focus effects for types of systems. Numerical ray tracing simulations are performed using density fields from large eddy simulations (LES) of a Mach 2 turbulent boundary layer to generate synthetic but realistic BOS images. The results show that telecentric systems have lower overall error and less sensitivity. The optimal standoff distance between the BOS background and the density gradient object is found to be 300% and 200% of the depth-of-field for entocentric and telecentric systems, respectively. Aeronautics and Astronautics background oriented schlieren turbulent boundary layer entocentric telecentric Full Text Additional Declarations The authors declare no competing interests. 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-5053181","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":351089295,"identity":"c7fa8f28-c693-4703-9217-7521fa3a5371","order_by":0,"name":"Tanbo Zhou","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA+klEQVRIiWNgGAWjYDADAwYGNiBlA8SMjQfwqeQBkwlwLWkgLQ0kaTkM5uPVYs/e++wz7w+7PHP29mcPPradt1vbfhhoS41NNE5beI4bz+ZJSC627DmQbjiz7XbytjOJQC3H0nIbcGmRSGNm5klgTtxwI+GYNC9Qi9kBoBbGhsO4tcg/A2mpB2pJbANqOZdsdv4hAS0SbCAth4FaktmAWg7Ymd0gZMuZNGbGOWnHE3f2HGOTnHEuOcHsBtCWBDx+YW8/xszwxqY6cTswxCQ+lNnZm51Pf/jgQ40NTi0gwMSDxEkEq0zAoxwEGH8gcewJKB4Fo2AUjIIRCACbuF626+zdVwAAAABJRU5ErkJggg==","orcid":"","institution":"Purdue University","correspondingAuthor":true,"prefix":"","firstName":"Tanbo","middleName":"","lastName":"Zhou","suffix":""},{"id":351089296,"identity":"10db302f-3c42-4e44-ab30-f836aedcca0a","order_by":1,"name":"Jonathan Gaskins","email":"","orcid":"","institution":"Purdue University","correspondingAuthor":false,"prefix":"","firstName":"Jonathan","middleName":"","lastName":"Gaskins","suffix":""},{"id":351089297,"identity":"32e856c4-4410-426a-9e39-a23e28dda117","order_by":2,"name":"Jonathan Poggie","email":"","orcid":"","institution":"Purdue University","correspondingAuthor":false,"prefix":"","firstName":"Jonathan","middleName":"","lastName":"Poggie","suffix":""},{"id":351089298,"identity":"36ef520b-13b6-4917-bee3-2a31d33768ad","order_by":3,"name":"Sally Bane","email":"","orcid":"","institution":"Purdue University","correspondingAuthor":false,"prefix":"","firstName":"Sally","middleName":"","lastName":"Bane","suffix":""}],"badges":[],"createdAt":"2024-09-08 14:46:17","currentVersionCode":1,"declarations":{"humanSubjects":false,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":false,"humanSubjectConsent":false,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-5053181/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5053181/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":64202330,"identity":"e88519cd-7c5f-4bea-a4ff-4e3959dbdcb5","added_by":"auto","created_at":"2024-09-10 02:59:43","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1964818,"visible":true,"origin":"","legend":"","description":"","filename":"OptimizationofBOSOpticsmeasurementscienceandtechnology.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5053181/v1_covered_21b381df-5ab8-49b1-8a47-c54747fcf4ae.pdf"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003eOptimization of Optical Systems for Background Oriented Schlieren\u003c/p\u003e","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"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":"background oriented schlieren, turbulent boundary layer, entocentric, telecentric","lastPublishedDoi":"10.21203/rs.3.rs-5053181/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5053181/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eBackground oriented schlieren (BOS) is a non-intrusive optical method for measuring density gradients in a fluid flow based on variations of the local refractive index. 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