Assessment of coarse-grained DEM accuracy in confined granular silo packings across multiple confinement scales

Assessment of coarse-grained DEM accuracy in confined granular silo packings across multiple confinement scales | 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 Assessment of coarse-grained DEM accuracy in confined granular silo packings across multiple confinement scales Ismain BABA AHMED, Nesrine ELHOUARI This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9355685/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 Coarse-graining in discrete element method (DEM) simulations is widely employed to reduce computational cost in large-scale granular systems. However, the practical validity limits of particle upscaling under confined silo conditions remain insufficiently quantified. This study investigates the confinement-dependent robustness of coarse-grained DEM simulations using superquadric particles representative of elongated grains. A fine-resolution reference configuration (λ = 1) is systematically compared with scaled systems up to λ = 2.5 under strictly identical material and boundary conditions. Macroscopic validation is performed through vertical bulk density profiles, global apparent density, heap height, and confined angle of repose. Results show that coarse-graining accuracy strongly depends on the ratio between particle size and confinement scale. Under intermediate confinement (20×20×50), macroscopic quantities remain stable up to λ ≈ 2, with density deviations below 5% and moderate angular variations. Small confinement geometries exhibit pronounced density sensitivity for λ ≥ 2 due to reduced particle representativity, whereas large systems display progressive but non-abrupt deviations at λ = 2.5. The results demonstrate that no universal scaling threshold exists independently of confinement geometry. Instead, coarse-graining validity emerges as a geometry-dependent property governed by particle resolution and observable sensitivity. The proposed framework provides practical guidelines for selecting coarse-graining factors in confined granular simulations while preserving macroscopic fidelity and computational efficiency. coarse-graining particle scaling Discret Element Method (DEM) confinement effects Full Text Additional Declarations No competing interests reported. Supplementary Files Graphicalabstract.tiff 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-9355685","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":634071552,"identity":"5dc72346-a218-47ad-a241-d30691e1876a","order_by":0,"name":"Ismain BABA AHMED","email":"data:image/png;base64,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","orcid":"","institution":"Aboubekr Belkaid University","correspondingAuthor":true,"prefix":"","firstName":"Ismain","middleName":"BABA","lastName":"AHMED","suffix":""},{"id":634071554,"identity":"24d198b1-7b54-45e8-aa20-8de4df27aca3","order_by":1,"name":"Nesrine ELHOUARI","email":"","orcid":"","institution":"Aboubekr Belkaid University","correspondingAuthor":false,"prefix":"","firstName":"Nesrine","middleName":"","lastName":"ELHOUARI","suffix":""}],"badges":[],"createdAt":"2026-04-08 10:45:06","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9355685/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9355685/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":108806107,"identity":"22a0b091-fc7c-4ba9-92ac-d7c92d28add3","added_by":"auto","created_at":"2026-05-08 15:27:41","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":777404,"visible":true,"origin":"","legend":"","description":"","filename":"IsmainBABAAHMED.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9355685/v1_covered_7b7869e4-a707-4cd3-9c06-b32096f8e885.pdf"},{"id":108666750,"identity":"12cd0591-ea73-488e-8a1a-f388dc9cefcb","added_by":"auto","created_at":"2026-05-07 06:42:19","extension":"tiff","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":168928,"visible":true,"origin":"","legend":"","description":"","filename":"Graphicalabstract.tiff","url":"https://assets-eu.researchsquare.com/files/rs-9355685/v1/50feb04f4bf02f478f26dc0b.tiff"}],"financialInterests":"No competing interests reported.","formattedTitle":"Assessment of coarse-grained DEM accuracy in confined granular silo packings across multiple confinement scales","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":"coarse-graining, particle scaling, Discret Element Method (DEM), confinement effects","lastPublishedDoi":"10.21203/rs.3.rs-9355685/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9355685/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eCoarse-graining in discrete element method (DEM) simulations is widely employed to reduce computational cost in large-scale granular systems. However, the practical validity limits of particle upscaling under confined silo conditions remain insufficiently quantified.\u003c/p\u003e \u003cp\u003eThis study investigates the confinement-dependent robustness of coarse-grained DEM simulations using superquadric particles representative of elongated grains. A fine-resolution reference configuration (λ\u0026thinsp;=\u0026thinsp;1) is systematically compared with scaled systems up to λ\u0026thinsp;=\u0026thinsp;2.5 under strictly identical material and boundary conditions.\u003c/p\u003e \u003cp\u003eMacroscopic validation is performed through vertical bulk density profiles, global apparent density, heap height, and confined angle of repose.\u003c/p\u003e \u003cp\u003eResults show that coarse-graining accuracy strongly depends on the ratio between particle size and confinement scale. Under intermediate confinement (20\u0026times;20\u0026times;50), macroscopic quantities remain stable up to λ\u0026thinsp;\u0026asymp;\u0026thinsp;2, with density deviations below 5% and moderate angular variations. Small confinement geometries exhibit pronounced density sensitivity for λ\u0026thinsp;\u0026ge;\u0026thinsp;2 due to reduced particle representativity, whereas large systems display progressive but non-abrupt deviations at λ\u0026thinsp;=\u0026thinsp;2.5.\u003c/p\u003e \u003cp\u003eThe results demonstrate that no universal scaling threshold exists independently of confinement geometry. Instead, coarse-graining validity emerges as a geometry-dependent property governed by particle resolution and observable sensitivity.\u003c/p\u003e \u003cp\u003eThe proposed framework provides practical guidelines for selecting coarse-graining factors in confined granular simulations while preserving macroscopic fidelity and computational efficiency.\u003c/p\u003e","manuscriptTitle":"Assessment of coarse-grained DEM accuracy in confined granular silo packings across multiple confinement scales","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-05-07 06:42:12","doi":"10.21203/rs.3.rs-9355685/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","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}}],"origin":"","ownerIdentity":"d5c20027-02bd-49eb-874f-9838312be1fd","owner":[],"postedDate":"May 7th, 2026","published":true,"recentEditorialEvents":[{"type":"reviewerAgreed","content":"292580114722925231491918569937432833971","date":"2026-05-04T10:45:51+00:00","index":9,"fulltext":""},{"type":"reviewersInvited","content":"3","date":"2026-04-29T08:52:17+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-04-29T04:19:27+00:00","index":"","fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-05-07T06:42:13+00:00","versionOfRecord":[],"versionCreatedAt":"2026-05-07 06:42:12","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9355685","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9355685","identity":"rs-9355685","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}