{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"8ffe02b3e02961a96657f749645a59d31b940de07c6bf98d7c839277deb563d3","created":"2026-10-03T07:18:03Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"1f43a2e763a27aed665aed78e05ee9feade3375f80b42dd53bcb7bb1b49fd4c0","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"fluid.particle-turbulence.finite-size-modulation","kind":"phenomenon","literature_status":"open","n":"1","parents":[],"plain":"Particles larger than the smallest eddies, carried by a turbulent flow, can either calm the turbulence or make it stronger through the wakes they shed. No reliable rule predicts which happens.","posed_since":"1989","precise":"For finite-size particles (diameter $d > \\eta$, particle-to-fluid density ratio, volume fraction $\\phi$) in homogeneous and wall-bounded turbulence, find a predictive criterion for whether carrier-phase turbulent kinetic energy increases or decreases, replacing the empirical threshold $d/L \\sim 0.1$ ($L$ integral scale; Gore and Crowe 1989), and derive the magnitude of the change.","problem_ref":null,"references":"","settled_by":"A theory validated by particle-resolved DNS and experiments over decades in $d/\\eta$, density ratio and $\\phi$.","status_note":"","title":"When do finite-size particles enhance or damp carrier turbulence?","topic_ref":"28a67e06c2d95a104488e4da0be70a03916f05f9e68b223b2403a21e1c4f018e"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"2f6b6bb8d468d7052d902555527978f8eebdc682f47a6247b74e46d2beb0645e","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"e5b979bbfd2f4b37b89bce8d956aee8e5fdfef8a069676e366d8faaa56991e4c","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"Vji58tBsiPN-subR6_q7ZgROKnW3Sxk-kZxZheUtnf02PA0MIjUFgwwO8rkgRrYN3DD55136IHY5k4ArQj6EDQ"},"schema":"pubphys.envelope/1"},"record_hash":"2f6b6bb8d468d7052d902555527978f8eebdc682f47a6247b74e46d2beb0645e","leaf_index":1414}