Vis enkel innførsel

dc.contributor.authorMazur, Marek
dc.contributor.authorNygård, Håkon Tormodsen
dc.contributor.authorDawson, James
dc.contributor.authorWorth, Nicholas
dc.date.accessioned2019-01-30T08:28:31Z
dc.date.available2019-01-30T08:28:31Z
dc.date.created2018-10-30T11:06:37Z
dc.date.issued2018
dc.identifier.issn0082-0784
dc.identifier.urihttp://hdl.handle.net/11250/2582979
dc.description.abstractIn this paper we investigate self-excited azimuthal modes in an annular combustor with turbulent premixed bluff-body stabilised flames. Previous studies have shown that both swirl and equivalence ratio influence modal dynamics, i.e. the time-varying nature of the modes. However, self-excited azimuthal modes have not yet been investigated in turbulent flames without bulk swirl, which do not generate any preferential flow in either azimuthal direction, and may therefore lead to different behaviour. Joint probability density functions of the instability amplitudes at various flowrates and equivalence ratios showed a strong bi-modal response favouring both ACW and CW spinning states not previously observed. Operating conditions leading to a bi-modal response provide a unique opportunity to investigate whether the structure of the global fluctuating heat release rate of self-excited spinning modes in both directions exhibit similar dynamics and structure. This was investigated using high-speed OH* chemiluminescence images of the annular combustor and a new rotational averaging method was applied which decomposes the spinning components of the global fluctuating heat release rate. The new rotational averaging, which differs from standard phase-averaging, produces spatial averages in a frame of reference moving with the spinning wave. The results show that the structure of the fluctuating heat release rate for spinning modes is highly asymmetric as characterised by large, crescent shaped regions of high OH* intensity, located on the far side of each flame, relative to the direction of the azimuthally propagating pressure wave. In comparison with interacting swirling flames, these results indicate that the previously observed radial asymmetry of OH* fluctuations may be introduced through advection by local swirl.nb_NO
dc.language.isoengnb_NO
dc.publisherElseviernb_NO
dc.rightsNavngivelse 4.0 Internasjonal*
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/deed.no*
dc.titleCharacteristics of self-excited spinning azimuthal modes in an annular combustor with turbulent premixed bluff-body flamesnb_NO
dc.title.alternativeCharacteristics of self-excited spinning azimuthal modes in an annular combustor with turbulent premixed bluff-body flamesnb_NO
dc.typeJournal articlenb_NO
dc.typePeer reviewednb_NO
dc.description.versionpublishedVersionnb_NO
dc.source.pagenumber5129-5136nb_NO
dc.source.volume37nb_NO
dc.source.journalSymposium, International, on combustionnb_NO
dc.source.issue4nb_NO
dc.identifier.doihttps://doi.org/10.1016/j.proci.2018.07.080
dc.identifier.cristin1624835
dc.description.localcode© 2018 The Author(s). Published by Elsevier Inc. on behalf of The Combustion Institute. This is an open access article under the CC BY license. (http://creativecommons.org/licenses/by/4.0/)nb_NO
cristin.unitcode194,64,25,0
cristin.unitnameInstitutt for energi- og prosessteknikk
cristin.ispublishedtrue
cristin.fulltextoriginal
cristin.qualitycode0


Tilhørende fil(er)

Thumbnail

Denne innførselen finnes i følgende samling(er)

Vis enkel innførsel

Navngivelse 4.0 Internasjonal
Med mindre annet er angitt, så er denne innførselen lisensiert som Navngivelse 4.0 Internasjonal