{"id":{"repo_id":"cent-lancashire","oai_identifier":"oai:clok.uclan.ac.uk:22774"},"canonical_url":"https://search.dev.ndltd.org/etd/cent-lancashire/oai:clok.uclan.ac.uk:22774","repository":{"repo_id":"cent-lancashire","name":"University of Central Lancashire","base_url":"https://clok.uclan.ac.uk/cgi/oai2"},"display":{"title":"Modelling of Ignition and Fire in Vented Enclosures","abstract":"Fire development in a vented enclosure can proceed in an explosive and disastrous manner called flashover. This thesis examines when, why and how flashover occurs and gives the answers in terms of a few determining dimensionless parameters. The mechanism of flashover considered in this thesis is an enhancement of the burning rate because of thermal radiation from a layer of hot smoke, produced in the course of the fire, to the fire bed. A model, which is proposed for the problem, describes the development fro~ the moment of ignition incorporating the traditional two-zone approach. During early fIre development the density and temperature of the lower zone are reasonably assumed to be close to their initial value. Flashover itself is assumed to occur early in the fIre development, within the fuel controlled combustion regime. The model is analysed using the techniques of classical thermal explosion theory. Explicit criteria are found analytically and graphically to determine if the fIre will achieve flashover or not. The temperature-time characteristics of the fIre development are obtained explicitly for the fIrst time. It is shown that the thermal inertia of the compartment walls can have a significant effect upon the development. The effect of geometrically scaling the compartment is considered. Nondimensional analysis makes such study effective and leads to a square root relationship for the temperature/time characteristics of the fire development. The correlation between the model, four prevIOUS models and small scale experiments is examined. Under reasonable assumptions all models are shown to be described by the same mathematical problem. This means that the criterion for flashover and the development characteristics can be used for any of the modified models observed. Results are illustrated for an experimental fire box used in many experiments.","abstract_html":"Fire development in a vented enclosure can proceed in an explosive and disastrous manner called flashover. This thesis examines when, why and how flashover occurs and gives the answers in terms of a few determining dimensionless parameters. The mechanism of flashover considered in this thesis is an enhancement of the burning rate because of thermal radiation from a layer of hot smoke, produced in the course of the fire, to the fire bed. A model, which is proposed for the problem, describes the development fro~ the moment of ignition incorporating the traditional two-zone approach. During early fIre development the density and temperature of the lower zone are reasonably assumed to be close to their initial value. Flashover itself is assumed to occur early in the fIre development, within the fuel controlled combustion regime. The model is analysed using the techniques of classical thermal explosion theory. Explicit criteria are found analytically and graphically to determine if the fIre will achieve flashover or not. The temperature-time characteristics of the fIre development are obtained explicitly for the fIrst time. It is shown that the thermal inertia of the compartment walls can have a significant effect upon the development. The effect of geometrically scaling the compartment is considered. Nondimensional analysis makes such study effective and leads to a square root relationship for the temperature/time characteristics of the fire development. The correlation between the model, four prevIOUS models and small scale experiments is examined. Under reasonable assumptions all models are shown to be described by the same mathematical problem. This means that the criterion for flashover and the development characteristics can be used for any of the modified models observed. Results are illustrated for an experimental fire box used in many experiments.","abstract_has_math":false,"creators":["Graham, Tony Lee"],"institution":"University of Central Lancashire","degree_name":"phd","degree_level":"doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1998,"date_issued":"1998-03","date_published":"1998-03","updated_at":"2026-07-24T01:36:23Z","subjects":["H121 - Fire safety engineering"],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Graham, Tony Lee"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["1998-03-01"]},{"key":"dc:date.issued","label":"Date","values":["1998-03"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Built Environment, Faculty of Design and Technology"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Central Lancashire"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://knowledge.lancashire.ac.uk/id/eprint/22774/"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["phd"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["H121 - Fire safety engineering"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://knowledge.lancashire.ac.uk/id/eprint/22774/1/22774%20Tony%20Lee%20Graham%20Volume%201.pdf","https://knowledge.lancashire.ac.uk/id/eprint/22774/2/22774%20Tony%20Lee%20Graham%20Volume%202.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Fire development in a vented enclosure can proceed in an explosive and disastrous manner called flashover. This thesis examines when, why and how flashover occurs and gives the answers in terms of a few determining dimensionless parameters. The mechanism of flashover considered in this thesis is an enhancement of the burning rate because of thermal radiation from a layer of hot smoke, produced in the course of the fire, to the fire bed. A model, which is proposed for the problem, describes the development fro~ the moment of ignition incorporating the traditional two-zone approach. During early fIre development the density and temperature of the lower zone are reasonably assumed to be close to their initial value. Flashover itself is assumed to occur early in the fIre development, within the fuel controlled combustion regime. The model is analysed using the techniques of classical thermal explosion theory. Explicit criteria are found analytically and graphically to determine if the fIre will achieve flashover or not. The temperature-time characteristics of the fIre development are obtained explicitly for the fIrst time. It is shown that the thermal inertia of the compartment walls can have a significant effect upon the development. The effect of geometrically scaling the compartment is considered. Nondimensional analysis makes such study effective and leads to a square root relationship for the temperature/time characteristics of the fire development. The correlation between the model, four prevIOUS models and small scale experiments is examined. Under reasonable assumptions all models are shown to be described by the same mathematical problem. This means that the criterion for flashover and the development characteristics can be used for any of the modified models observed. Results are illustrated for an experimental fire box used in many experiments."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Modelling of Ignition and Fire in Vented Enclosures"]}]}],"canonical_facts":{"dc:creator":["Graham, Tony Lee"],"dc:date":["1998-03-01"],"dc:date.issued":["1998-03"],"dc:description.abstract":["Fire development in a vented enclosure can proceed in an explosive and disastrous manner called flashover. This thesis examines when, why and how flashover occurs and gives the answers in terms of a few determining dimensionless parameters. The mechanism of flashover considered in this thesis is an enhancement of the burning rate because of thermal radiation from a layer of hot smoke, produced in the course of the fire, to the fire bed. A model, which is proposed for the problem, describes the development fro~ the moment of ignition incorporating the traditional two-zone approach. During early fIre development the density and temperature of the lower zone are reasonably assumed to be close to their initial value. Flashover itself is assumed to occur early in the fIre development, within the fuel controlled combustion regime. The model is analysed using the techniques of classical thermal explosion theory. Explicit criteria are found analytically and graphically to determine if the fIre will achieve flashover or not. The temperature-time characteristics of the fIre development are obtained explicitly for the fIrst time. It is shown that the thermal inertia of the compartment walls can have a significant effect upon the development. The effect of geometrically scaling the compartment is considered. Nondimensional analysis makes such study effective and leads to a square root relationship for the temperature/time characteristics of the fire development. The correlation between the model, four prevIOUS models and small scale experiments is examined. Under reasonable assumptions all models are shown to be described by the same mathematical problem. This means that the criterion for flashover and the development characteristics can be used for any of the modified models observed. Results are illustrated for an experimental fire box used in many experiments."],"dc:format":["application/pdf"],"dc:identifier.uri":["https://knowledge.lancashire.ac.uk/id/eprint/22774/1/22774%20Tony%20Lee%20Graham%20Volume%201.pdf","https://knowledge.lancashire.ac.uk/id/eprint/22774/2/22774%20Tony%20Lee%20Graham%20Volume%202.pdf"],"dc:language":["en"],"dc:publisher.department":["Built Environment, Faculty of Design and Technology"],"dc:publisher.institution":["University of Central Lancashire"],"dc:relation.isreferencedby":["https://knowledge.lancashire.ac.uk/id/eprint/22774/"],"dc:subject":["H121 - Fire safety engineering"],"dc:title":["Modelling of Ignition and Fire in Vented Enclosures"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["doctoral"],"dc:type.qualificationname":["phd"]},"updated_at":"2026-07-24T01:36:23Z"}