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Numerical modeling of spectral radiative properties of fuel vapors in fires

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dc.contributor Aalto-yliopisto fi
dc.contributor Aalto University en
dc.contributor.advisor Bordbar, Hadi
dc.contributor.author Sadeghi, Hosein
dc.date.accessioned 2022-05-06T09:00:45Z
dc.date.available 2022-05-06T09:00:45Z
dc.date.issued 2022
dc.identifier.uri https://aaltodoc.aalto.fi/handle/123456789/114149
dc.description.abstract In combustion and fire, fuel vapors emerge in the gasification phase. Experimental studies have shown that the amount of these vapors close to the fuel surface is considerably high. It, therefore, alters radiative heat flux reaching the fuel and consequently, the fuel mass loss rate and the combustion mechanism. Due to the spectral nature of thermal radiation and the strong dependency of spectral radiative properties of fuel gases on temperature, there is a need for suitable models to account for the effect of fuel gases in radiative heat transfer. In this work, non-gray thermal radiation in fuel vapors is studied and novel weighted-sum-of-gray gases models (WSGG) are developed for Heptane, Methane, Methanol, MMA, Propane, Propylene, Toluene, Carbon Monoxide and soot. To develop the WSGG models, experimentally measured high-resolution spectral absorption data are used for Heptane, Methane, Methanol, MMA, Propane, Propylene and Toluene and line-by-line spectral data are employed for Methane and Carbon Monoxide. For soot, the complex index of refraction is calculated by the correlations of Chang and Charalampopoulos. The soot spectral absorption coefficient is then calculated assuming Rayleigh regime for soot particles. The obtained WSGG models are validated in five one-dimensional cases and in a three-dimensional case. The superposition method is employed to mix WSGG models of different species. In all the cases, the results obtained from the WSGG modeling are compared with line-by-line integration and they show a good accuracy. The method increased the number of required solutions of radiative transfer equation (RTE) up to 2500 in some cases but using premixed WSGG models for H2O-CO2 mixture, the number of the required RTE solutions decreased to 25 gases. Compared to the gray solution, the CPU time of the WSGG modeling with 25 gray gases was 12.9 times higher, however, the average error of heat source decreased from 18.3% for gray solution to 3.93% for WSGG modeling compared to LBL integration. en
dc.format.extent 48+32
dc.format.mimetype application/pdf en
dc.language.iso en en
dc.publisher Aalto-yliopisto fi
dc.publisher Aalto University en
dc.subject.other Civil engineering en
dc.subject.other Physics en
dc.title Numerical modeling of spectral radiative properties of fuel vapors in fires en
dc.type G3 Lisensiaatintutkimus fi
dc.contributor.school Insinööritieteiden korkeakoulu fi
dc.contributor.school School of Engineering en
dc.contributor.department Rakennustekniikan laitos fi
dc.contributor.department Department of Civil Engineering en
dc.subject.keyword Spectral radiative heat transfer en
dc.subject.keyword Non-gray modeling en
dc.subject.keyword WSGG en
dc.subject.keyword Fuel vapor en
dc.identifier.urn URN:NBN:fi:aalto-202205053018
dc.type.ontasot Licentiate thesis en
dc.type.ontasot Lisensiaatintyö fi
dc.contributor.supervisor Hostikka, Simo
dc.rev Saxén, Henrik
local.aalto.openaccess yes
dc.rights.accesslevel openAccess en
local.aalto.formfolder 2022_05_05_klo_14_58

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