exported
equivalent
diffuser
IRI:
http://www.inf.ufrgs.br/ontologies/copi#Diffuser
Generated on 2026-04-16
Natural Language Definition
EN
A diffuser is an assembly that has the designed function of converting kinetic energy of fluid flow into pressure energy through controlled deceleration in a diverging passage.
PT-BR
Um difusor é um conjunto que tem a função projetada de converter energia cinética do fluxo de fluido em energia de pressão através de desaceleração controlada em uma passagem divergente.
Formal Axioms
Semi-formal (Aristotelian)
Every diffuser is an assembly that bears an energy diffusion function and has a diverging channel as component part at all times.
First-Order Logic Theory
Loading…
▸ Stored override
∀x(Diffuser(x) ↔ Assembly(x) ∧ ∃f(EnergyDiffusionFunction(f) ∧ bearerOf(x,f)) ∧ ∃p(DivergingChannel(p) ∧ hasComponentPartAtAllTimes(x,p)))
OWL 2 / Turtle
@prefix copi: <https://www.inf.ufrgs.br/ontologies/copi/> .
@prefix : <https://www.inf.ufrgs.br/ontologies/copi/> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix bfo: <http://purl.obolibrary.org/obo/> .
@prefix iof-core: <https://spec.industrialontologies.org/ontology/construct/> .
@prefix iof-av: <https://spec.industrialontologies.org/ontology/annotation/> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .
@prefix qudt: <http://qudt.org/schema/qudt/> .
@prefix dcterms: <http://purl.org/dc/terms/> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix apv: <http://inf.ufrgs.br/ontologies/apv#> .
### COPI — Core Ontology for Petroleum Installations
### Class module: Diffuser
<https://www.inf.ufrgs.br/ontologies/copi>
rdf:type owl:Ontology ;
dcterms:title "Core Ontology for Petroleum Installations (COPI)"@en ;
dcterms:title "Ontologia Core para Instalações de Petróleo (COPI)"@pt-br ;
dcterms:description "BFO/IOF-Core conformant ontology of equipment classes for petroleum production plants, developed using the five-step RDL enrichment method."@en ;
skos:scopeNote "Material artifacts (bfo:material_entity) that (i) are part of a petroleum production plant, and (ii) bear at least one function whose realization involves the transport (e.g. production and injection), processing (separation and other processes), control, monitoring, measurement, containment or offloading of material or energy."@en ;
skos:scopeNote "Artefatos materiais (bfo:material_entity) que (i) fazem parte de uma planta de produção de petróleo, e (ii) possuem ao menos uma função cuja realização envolve o transporte (p. ex. produção e injeção), processamento (separação e outros processos), controle, monitoramento, medição, contenção ou escoamento de material ou energia."@pt-br ;
skos:scopeNote "COPI provides high-level equipment categories defined by function to demonstrate the defined-class mechanism. Equipment subtypes are annotated with references to CFIHOS and PCA RDL terms. COPI is not a reference data library; organizations should use CFIHOS, PCA RDL, or ISO 14224 for comprehensive equipment classification."@en ;
skos:scopeNote "COPI fornece categorias de alto nível de equipamentos definidas por função para demonstrar o mecanismo de classe definida. Os subtipos de equipamentos são anotados com referências aos termos do CFIHOS e do PCA RDL. COPI não é uma biblioteca de dados de referência; organizações devem utilizar o CFIHOS, o PCA RDL ou a ISO 14224 para classificação abrangente de equipamentos."@pt-br ;
owl:versionInfo "1.1.0" ;
owl:imports <https://spec.industrialontologies.org/ontology/core/Core/> ;
owl:imports <http://purl.obolibrary.org/obo/bfo/2020/bfo.owl> ;
dcterms:creator "Nicolau Oyhenard dos Santos"@en ;
dcterms:contributor "Cauã Antunes" ;
dcterms:contributor "Haroldo Rojas" ;
dcterms:contributor "Rafael Petry" ;
dcterms:contributor "Régis Romeu" ;
dcterms:contributor "Mara Abel" ;
dcterms:isPartOf <https://inf.ufrgs.br/projetos/OntoKG> ;
dcterms:publisher "Universidade Federal do Rio Grande do Sul (UFRGS)"@en ;
dcterms:license <https://creativecommons.org/licenses/by/4.0/> ;
dcterms:created "2026-04-08"^^xsd:date ;
dcterms:modified "2026-10-08"^^xsd:date ;
apv:GlobalMinLanguageCoverage "en pt-br" ;
apv:ClassURIFormationRule "https://www[.]inf[.]ufrgs[.]br/ontologies/copi/(COPI_[0-9]{7}|[A-Z][A-Za-z0-9]*)" ;
apv:ClassMinAnnotationCoverage "rdfs:label https://spec.industrialontologies.org/ontology/annotation/naturalLanguageDefinition" .
iof-av:naturalLanguageDefinition rdf:type owl:AnnotationProperty ;
apv:MinAnnotationLength 20 .
### Identity-giving function
:COPI_0000502 rdf:type owl:Class ; # EnergyDiffusionFunction
rdfs:subClassOf iof-core:DesignedFunction ;
rdfs:subClassOf [
rdf:type owl:Restriction ;
owl:onProperty bfo:BFO_0000054 ; # realizedIn
owl:allValuesFrom :COPI_0000503 # EnergyDiffusionProcess
] ;
rdfs:subClassOf [
rdf:type owl:Restriction ;
owl:onProperty bfo:BFO_0000054 ; # realizedIn
owl:someValuesFrom :COPI_0000503 # EnergyDiffusionProcess
] ;
rdfs:label "energy diffusion function"@en ;
rdfs:label "função de difusão de energia"@pt-br .
### Process type
:COPI_0000503 rdf:type owl:Class ; # EnergyDiffusionProcess
rdfs:subClassOf :COPI_0000003 ; # MomentumTransfer
rdfs:label "energy diffusion process"@en ;
rdfs:label "processo de difusão de energia"@pt-br .
:COPI_0000003 rdf:type owl:Class . # MomentumTransfer
:COPI_0000503 # EnergyDiffusionProcess
rdfs:subClassOf [
rdf:type owl:Restriction ;
owl:onProperty iof-core:hasInput ;
owl:someValuesFrom :COPI_0000037 # PortionOfFluid
] ;
rdfs:subClassOf [
rdf:type owl:Restriction ;
owl:onProperty iof-core:hasSpecifiedOutput ;
owl:someValuesFrom :COPI_0000037 # PortionOfFluid
] .
### Equipment universal: Diffuser
:COPI_0000253 rdf:type owl:Class ; # Diffuser
owl:equivalentClass [
rdf:type owl:Class ;
owl:intersectionOf (
iof-core:Assembly
[
rdf:type owl:Restriction ;
owl:onProperty iof-core:hasFunction ; # Object branch (MaterialArtifact/Assembly/Object/FiatObjectPart)
owl:someValuesFrom :COPI_0000502 # EnergyDiffusionFunction
]
[
rdf:type owl:Restriction ;
owl:onProperty iof-core:hasComponentPartAtAllTimes ;
owl:someValuesFrom :COPI_0000476 # DivergingChannel
]
)
] ;
rdfs:label "diffuser"@en ;
rdfs:label "difusor"@pt-br ;
iof-av:naturalLanguageDefinition "A diffuser is an assembly that has the designed function of converting kinetic energy of fluid flow into pressure energy through controlled deceleration in a diverging passage."@en ;
skos:definition "A diffuser is an assembly that has the designed function of converting kinetic energy of fluid flow into pressure energy through controlled deceleration in a diverging passage."@en ;
iof-av:naturalLanguageDefinition "Um difusor é um conjunto que tem a função projetada de converter energia cinética do fluxo de fluido em energia de pressão através de desaceleração controlada em uma passagem divergente."@pt-br ;
iof-av:semiFormalNaturalLanguageAxiom "Every diffuser is an assembly that bears an energy diffusion function and has a diverging channel as component part at all times."@en ;
iof-av:firstOrderLogicAxiom "∀x(Diffuser(x) ↔ Assembly(x) ∧ ∃f(EnergyDiffusionFunction(f) ∧ bearerOf(x,f)) ∧ ∃p(DivergingChannel(p) ∧ hasComponentPartAtAllTimes(x,p)))"@en ;
skos:definition "[ISO 15926-4] A <DIFFUSER> is a <FunctionalObject> that has the capability of <DIFFUSING> which is used in pumps to convert kinetic energy imparted by impeller to potential energy i.e. pressure head."@en ;
skos:definition "[CFIHOS] A physical object that contains a diverging channel-shaped chamber in which part of the kinetic energy of the fluid is converted into pressure energy."@en .
:COPI_0000476 rdf:type owl:Class ; # DivergingChannel
rdfs:subClassOf iof-core:MaterialArtifact ;
rdfs:label "canal divergente"@pt-br ;
rdfs:label "diverging channel"@en .
# Disjointness: Diffuser and Nozzle
[] rdf:type owl:AllDisjointClasses ;
owl:members ( :COPI_0000253 :COPI_0000316 ) . # Diffuser, Nozzle
Axiomatization Decision Log
1
Identity-Giving Function
Function class
EnergyDiffusionFunction
⊑ DesignedFunction
Realized in
EnergyDiffusionProcess
⊑ MomentumTransfer
The identity-giving function is the conversion of kinetic energy to pressure energy (potential energy) in fluid flows. This is what makes a diffuser a diffuser across all contexts - pumps, HVAC, turbomachinery, etc. The function is realized through controlled deceleration of fluid in a diverging passage.
2
Genus Determination
Assembly
bfo:Object (BFO_0000030)
Causally unified material artefact composed of physically connected,
separable MaterialComponent parts. Satisfies
Assembly ⊑ MaterialArtifact ⊑ bfo:Object.
From the parent candidates, FunctionalObject is too abstract and 'other mechanical equipment' is not a proper ontological class. Diffuser is a mechanical component with multiple parts (typically housing, diverging channel walls, possibly vanes or guide elements) that work together as a causally unified assembly. It's procured, maintained, and operated as a single unit despite having internal structure.
3
Necessary Parts
| Part class | Parent | Relation |
|---|---|---|
| DivergingChannel | MaterialArtifact | hasComponentPartAtAllTimes |
These parts are universal - any device performing energy diffusion must have a diverging geometry and flow guidance elements, though specific implementations vary by application.
4
Process Participation Signature ⟨I, O, T⟩
Inputs (I)
PortionOfFluid
— high kinetic energy, low pressure
Outputs (O)
PortionOfFluid
— low kinetic energy, high pressure
Transformation (T)
kinetic energy converted to pressure energy through controlled fluid deceleration
The signature captures the essential energy transformation - single fluid stream with kinetic energy reduced and pressure energy increased, maintaining mass conservation but transforming energy state.
5
Axiom Mode Decision
Necessary + Sufficient
— modelled as a defined class
(≡, EquivalentClass). Automatic classification is
appropriate for this concept.
Disjointness Axioms
Nozzle
C4: Nozzle. Nozzle performs opposite transformation (pressure to kinetic energy), Venturi creates pressure drop rather than pressure rise. These represent incompatible energy transformation signatures.
Cross-Standard Observations
ISO 15926 emphasizes the pump application context while CFIHOS provides a more general fluid mechanics definition. Both capture the core energy conversion function, but ISO's definition is more specific to turbomachinery applications. The CFIHOS definition better captures the universal principle applicable across all diffuser types.
