{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.circulation","code":"thing-q205880","url":"https://ver.cy/models/thing/q205880/","name":"circulation","alternateNames":[],"kind":"thing","status":"published","version":"0.2.0-wave.3","language":"en","classifiers":{"family":"Thing Registry","category":"Cross-cutting context","entryKind":"thing","plane":"XCT","domain":["XCT.QTY"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"In fluid dynamics, the line integral of the velocity field around a closed curve, a scalar quantity that measures the macroscopic rotation of a fluid around that curve, related to vorticity by Stokes theorem, conserved by Kelvin circulation theorem for a closed material curve moving with an inviscid barotropic fluid under conservative body forces, and central to the theory of lift on wings through the Kutta-Joukowski theorem; the word circulation also names blood circulation, atmospheric and ocean circulation, newspaper circulation and library circulation, which are separate concepts.","purpose":"Let an agent explain circulation as a fluid dynamics quantity, relay its definition, theorems and role in aerodynamics from physics references, and distinguish it from the other senses of circulation.","scope":{"in":[],"out":[],"boundaries":[]},"distinguishingFeatures":["Line integral definition","Vorticity link","Kelvin conservation","Lift theorem"],"structure":{"bundles":[{"id":"understand","name":"Understand","description":"What circulation is.","layers":[{"id":"definition","name":"Definition","description":"Definition.","findings":[{"id":"definition-finding","name":"Definition","description":"Definition.","questions":[{"text":"How is circulation defined as a line integral, and how does it relate to vorticity?","kind":"definition"},{"text":"Is the question about fluid circulation or blood, atmospheric, newspaper or library circulation?","kind":"boundary"}]}]},{"id":"theorems","name":"Theorems","description":"Theorems.","findings":[{"id":"theorems-finding","name":"Theorems","description":"Theorems.","questions":[{"text":"What do Stokes theorem and Kelvin circulation theorem say about circulation?","kind":"definition"},{"text":"Which entry fits the specific theorem?","kind":"action"}]}]}]},{"id":"apply","name":"Apply","description":"Applications.","layers":[{"id":"lift","name":"Lift","description":"Aerodynamic lift.","findings":[{"id":"lift-finding","name":"Lift","description":"Lift.","questions":[{"text":"How does circulation around an airfoil produce lift through the Kutta-Joukowski theorem?","kind":"provenance"},{"text":"Which references are standard?","kind":"provenance"}]}]},{"id":"vortices","name":"Vortices","description":"Vortices and geophysics.","findings":[{"id":"vortices-finding","name":"Vortices","description":"Vortices.","questions":[{"text":"How is circulation used to describe vortices, tornadoes and ocean eddies?","kind":"provenance"},{"text":"Which entry fits vortex?","kind":"action"}]}]}]},{"id":"compute","name":"Compute","description":"Computation.","layers":[{"id":"methods","name":"Methods","description":"Computing circulation.","findings":[{"id":"methods-finding","name":"Methods","description":"Methods.","questions":[{"text":"How is circulation computed analytically and in computational fluid dynamics?","kind":"action"},{"text":"Which sources are cited?","kind":"provenance"}]}]},{"id":"measurement","name":"Measurement","description":"Measurement.","findings":[{"id":"measurement-finding","name":"Measurement","description":"Measurement.","questions":[{"text":"How is circulation measured experimentally, for example with particle image velocimetry?","kind":"provenance"},{"text":"Which entry fits particle image velocimetry?","kind":"action"}]}]}]},{"id":"context","name":"Context","description":"History and homonyms.","layers":[{"id":"history","name":"History","description":"History.","findings":[{"id":"history-finding","name":"History","description":"History.","questions":[{"text":"How did Kelvin, Helmholtz, Kutta and Joukowski develop circulation theory?","kind":"provenance"},{"text":"Which entry fits the history of aerodynamics?","kind":"action"}]}]},{"id":"homonyms","name":"Homonyms","description":"Other senses.","findings":[{"id":"homonyms-finding","name":"Homonyms","description":"Homonyms.","questions":[{"text":"What are blood, atmospheric, ocean, newspaper and library circulation, and where are they covered?","kind":"provenance"},{"text":"Which entry fits the specific sense?","kind":"action"}]}]}]}]},"agentConduct":{"may":["Compute and explain circulation of a velocity field around a closed curve.","Use circulation in aerodynamic or fluid analysis it is authorized to perform."],"mustNot":["Confuse circulation in fluid dynamics with blood or traffic circulation.","Present simulated circulation or lift values as tested results.","Hide errors in lift calculations used for aircraft or structure safety."],"requiresHuman":["Approving designs whose safety depends on circulation and lift calculations."]},"ethics":{"considerations":["Aerodynamic calculations underpin aircraft and bridges whose failure kills people.","Teaching material should be accurate because students rely on it."],"affectedParties":["Engineers and students","Users of designed aircraft and structures"]},"owners":{"steward":"Nobody owns the concept; it is held in common.","roles":[],"masterSystems":[]},"relations":[{"target":"Q3677951","type":"parent","note":"registry parent class"},{"target":"circulation","type":"related","note":"in registry terms, the general concept"},{"target":"vorticity","type":"related","note":"by Stokes theorem"},{"target":"Kelvin circulation theorem","type":"related","note":"in ideal flow"},{"target":"lift","type":"related","note":"through the Kutta-Joukowski theorem"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.circulation","Wikidata: Q205880 (https://www.wikidata.org/wiki/Q205880)"]},"properties":{"applicability":"not-applicable","items":["SI unit: m^2/s unit","lift per unit span: rho V Gamma formula - Kutta-Joukowski"]},"recognition":{"applicability":"optional","items":["Line integral of velocity around a closed curve","Circulation in fluid dynamics, related to vorticity and lift","Blood, atmospheric, ocean, newspaper and library circulation are different concepts","Not a visible object; a quantity computed around a curve."]},"capabilities":{"applicability":"required","items":["explain the definition","relay theorems","describe role in lift","distinguish other senses"]},"hazards":{"applicability":"required","items":["Confusing with other senses of circulation","Sign convention errors","Applying conservation where viscosity matters"]},"interfaces":{"applicability":"required","items":["No regulation; standard fluid dynamics definitions"]},"context":{"applicability":"required","items":["Not applicable; a physical quantity.","circulation around an airfoil","circulation in vortices","circulation in meteorology and oceanography as a fluid quantity","homonyms: blood circulation, atmospheric circulation, newspaper circulation, library circulation"]}},"sources":[{"title":"Wikidata item Q205880: circulation","url":"https://www.wikidata.org/wiki/Q205880","note":"identity and sense of the item"},{"title":"Wikipedia: Circulation (physics)","url":"https://en.wikipedia.org/wiki/Circulation_%28physics%29","note":"general description of the item"}],"openQuestions":["Should the homonyms be separate entries?","How should physics references be linked?","How should meteorological usage be recorded?"],"resources":{"spec":"/models/things/publications/thing-q205880/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q205880/spec.json"],"providers":["Claude"],"researchStatus":"unreviewed","generatedAt":"2026-09-13T03:18:30Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"filled","ethics":"filled","owners":"filled","relations":"filled","interaction.identity":"filled","interaction.properties":"not-applicable","interaction.recognition":"filled","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"filled","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-07T10:10:28+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass","interaction.properties":"Plane XCT: no invented physical properties."},"score":1.0}}