Repository logo
 

A laser-induced breakdown spectroscopy method to assess the stochasticity of plasma-flame transition in sprays

Simple item page
dc.contributor.authorde Oliveira, Pedro M
dc.contributor.authorSitte, Michael Philip
dc.contributor.authorKotzagianni, Maria
dc.contributor.authorM Allison, Patton
dc.contributor.authorMastorakos, Epaminondas
dc.contributor.orcidMastorakos, Epaminondas [0000-0001-8245-5188]
dc.date.accessioned2022-06-08T14:00:06Z
dc.date.available2022-06-08T14:00:06Z
dc.date.issued2022-06-08
dc.date.submitted2022-01-20
dc.date.updated2022-06-08T14:00:05Z
dc.description.abstractAbstract: An experimental approach is presented to evaluate the impact of plasma composition arising from pulse-to-pulse energy and mixture fluctuations on the non-resonant laser-induced ignition of sprays. This allows for spark events to be conditioned on the successful or failed establishment of a flame kernel, a phase dominated by plasma decomposition and recombination reactions and the on-set of combustion reactions, that is, independent of the subsequent flame growth phase controlled by propagation phenomena only, such as fuel availability and turbulent strain. For that, laser-induced breakdown spectroscopy of the spark-generated plasma is carried out, followed by OH ∗ high-speed imaging of the kernel. Exploratory experiments in spatially uniform and polydisperse kerosene droplet distributions in a jet suggest that the hydrogen concentration in the plasma deriving from the fuel dissociated by the spark is closely related to the generated OH ∗ radicals levels and, in turn, with the success of establishing a flame kernel. This suggests that the ignition process is heavily controlled by mixture fluctuations at the spark, inherent of spray flows. The instantaneous mixture at the spark is estimated with a stochastic model, with the probability density function of the equivalence ratio exhibiting values higher than twice the mean value, while the highest probability occurs at lean conditions between the gaseous equivalence ratio and the overall equivalence ratio. The findings corroborate insights on the early-phase ignition obtained from direct numerical simulations, and the framework paves the way for the development of smart online engine-health tools to assess relight capability in future aeroengines.
dc.identifier.doi10.17863/CAM.85309
dc.identifier.eissn1361-6501
dc.identifier.issn0957-0233
dc.identifier.othermstac7436
dc.identifier.otherac7436
dc.identifier.othermst-114267.r1
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/337903
dc.languageen
dc.publisherIOP Publishing
dc.subjectPaper
dc.subjectFluids
dc.subjectlaser-induced breakdown spectroscopy
dc.subjectLIBS
dc.subjectignition
dc.subjectplasma-flame transition
dc.subjectspray combustion
dc.subjectpolydisperse sprays
dc.titleA laser-induced breakdown spectroscopy method to assess the stochasticity of plasma-flame transition in sprays
dc.typeArticle
dcterms.dateAccepted2022-05-27
prism.issueIdentifier9
prism.publicationNameMeasurement Science and Technology
prism.volume33
pubs.funder-project-idEuropean Commission Clean Sky 2 (Proteus (785349))
pubs.funder-project-idConselho Nacional de Desenvolvimento Científico e Tecnológico (Project #203086/2015-5)
rioxxterms.licenseref.urihttp://creativecommons.org/licenses/by/4.0
rioxxterms.versionVoR
rioxxterms.versionofrecord10.1088/1361-6501/ac7436

Files

Original bundle
Now showing 1 - 2 of 2
No Thumbnail Available
Name:
metadata.xml
Size:
10.95 KB
Format:
Extensible Markup Language
Description:
Bibliographic metadata
Licence
http://creativecommons.org/licenses/by/4.0
Download
Thumbnail Image
Name:
pdf.pdf
Size:
3.24 MB
Format:
Adobe Portable Document Format
Description:
Published version
Licence
http://creativecommons.org/licenses/by/4.0
Download

Collections

Jisc Publications Router