{"paper":{"title":"A multiple-scales framework for branched channel filters","license":"http://creativecommons.org/licenses/by/4.0/","headline":"Multiple-scales analysis produces an effective leakage boundary condition for flow over branched channel filters.","cross_cats":[],"primary_cat":"physics.flu-dyn","authors_text":"C. J. W. Breward, I. M. Griffiths, T. Fastnedge","submitted_at":"2025-11-07T11:22:33Z","abstract_excerpt":"Fibres shed from our clothes during a washing machine cycle constitute around 35% of the primary microplastics in our oceans. Current conventional dead-end washing machine filters clog relatively quickly and require frequent cleaning. We consider a new concept, ricochet separation, inspired by the feeding process of manta rays, to reduce the cleaning frequency. In such a device, some fluid is diverted through branched channels whilst particles ricochet off the wall structure, forcing them back into the main flow and then into the dead-end filter.\n  In this paper, we consider a simple branched-"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"We use multiple-scales techniques to derive an effective leakage boundary condition, which smooths out localised effects in the flow velocity and pressure that arise due to the discrete branched channels, and then use this boundary condition to explicitly determine the flow away from the boundary. We find that our explicit solution compares well with an analogous numerical solution containing a discrete set of branched channels.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The branch separation is much larger than the thickness of the viscous boundary layer under high-Reynolds-number laminar flow; if this scale separation fails the multiple-scales reduction to an effective boundary condition no longer holds.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Multiple-scales analysis derives an effective leakage boundary condition for high-Re laminar flow over branched channels, enabling explicit flow solutions and Stokes-number-dependent predictions of particle capture efficiency in a ricochet filter.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Multiple-scales analysis produces an effective leakage boundary condition for flow over branched channel filters.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"5f8921e1d51294dfd750c1ae6b4d6fef77cb6771dd6cdf74e99686df2b8d3e26"},"source":{"id":"2511.05157","kind":"arxiv","version":2},"verdict":{"id":"a26c89ff-f31d-449b-82d1-1edfa8647d80","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-18T00:33:56.009051Z","strongest_claim":"We use multiple-scales techniques to derive an effective leakage boundary condition, which smooths out localised effects in the flow velocity and pressure that arise due to the discrete branched channels, and then use this boundary condition to explicitly determine the flow away from the boundary. We find that our explicit solution compares well with an analogous numerical solution containing a discrete set of branched channels.","one_line_summary":"Multiple-scales analysis derives an effective leakage boundary condition for high-Re laminar flow over branched channels, enabling explicit flow solutions and Stokes-number-dependent predictions of particle capture efficiency in a ricochet filter.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The branch separation is much larger than the thickness of the viscous boundary layer under high-Reynolds-number laminar flow; if this scale separation fails the multiple-scales reduction to an effective boundary condition no longer holds.","pith_extraction_headline":"Multiple-scales analysis produces an effective leakage boundary condition for flow over branched channel filters."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2511.05157/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":3,"sample":[{"doi":"","year":2021,"title":"ACHARYA, S., SHAIDA, S. R., YANG, H. & NOUREDDINE, A. 2021 Microfibers from synthetic textiles as a major source of microplastics in the environment: A review. Text. Res. J. 91 (17-18), 2136–2156. AKA","work_id":"f23f8a41-a80e-4496-a9d1-dee18dc66b1e","ref_index":1,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2018,"title":"DIVI, R. V., STROTHER, J. A. & PAIG-TRAN, E. W. M. 2018 Manta rays feed using ricochet separation, a novel nonclogging filtration mechanism. Sci. Adv. 4 (9). DRIS, R., IMHOF, H. I., SANCHEZ, W. & GASP","work_id":"2a0141b0-a211-4ae7-a19d-b5fb55658f3b","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2023,"title":"2023 Suspension feeders as biological models to develop biomimetic filter modules and reduce microplastic emissions","work_id":"913eab23-d1f9-4875-9e27-c841365578e9","ref_index":3,"cited_arxiv_id":"","is_internal_anchor":false}],"resolved_work":3,"snapshot_sha256":"759eb7719acfd28babec926cbb077d8878f37d542f9a32a988d41dbcfee3df5b","internal_anchors":0},"formal_canon":{"evidence_count":1,"snapshot_sha256":"55e21584d0451f7f1495e07cdf6be02a27182a411985cbac85e39fb9b52111bb"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}