Instabilities and soot formation in high-pressure, rich, iso-octane–air explosion flames1. Dynamical structure

Lockett, R. D.; Woolley, Robert

doi:10.1016/j.combustflame.2007.08.004

Cited by 6 publications

(3 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Here, low to intermediate strain rates prevail (right). There is some overlap of soot presence and regions of globally high in-flow velocities where soot formation is not expected to occur due to the long time scales of soot chemistry [13][14][15], and of higher mean strain rates. The potential origin of those soot filaments is therefore discussed in the last section which indicates the importance of instantaneous correlations of both quantities.…”

Section: Spatial Correlation Of Soot Presence and Mean Flow Fieldmentioning

confidence: 99%

“…The direct correlation of flow field and soot distribution, however, is further complicated by the different time scales of soot chemistry and turbulence. Soot chemistry is typically described as a relatively slow process on the order of several milliseconds (for example [13][14][15]). Dependent on the location in the flame, time scales of the flow field cover a significantly wider range from submilliseconds close to the flame front to multiple milliseconds in the inner recirculation zone, which rather would require a time-resolved determination of the correlation of soot and flow field.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Flow field characterization of pressurized sooting swirl flames and relation to soot distributions

Geigle

Hadef

Stöhr

et al. 2017

Proceedings of the Combustion Institute

View full text Add to dashboard Cite

Mean and instantaneous flow fields were derived for sooting pressurized swirl flames, operated with ethylene/air in an aero-engine model combustor. Stereo particle image velocimetry served to deduce three velocity components and to identify locations of soot based on soot scattering. The measurements complement those of other quantities in the same flames published recently. Flow fields determined for cold and reactive conditions confirm conclusions drawn from application of other laser-based diagnostics: soot is mainly formed in the inner recirculation zone which recirculates reactive, hot unburnt reaction products, and partly transported into the high-velocity in-flow regions. Oxidation air injected after two thirds of the combustor forms a stagnation zone close to the combustor axis and splits into a portion flowing downstream towards the combustor exit and one transported upstream thereby affecting the local gas composition and temperatures in the inner recirculation zone. Analysis of the instantaneous images by proper orthogonal decomposition reveals the existence of a precessing vortex core which impacts the soot distribution. Presence of soot in high-velocity/high strain rate regions where soot formation is unlikely to occur can be explained as a result of transport. Flow field characterization and the correlation with soot presence, in complement of existing data, are expected to provide a valuable contribution to soot model validation.

show abstract

Section: Spatial Correlation Of Soot Presence and Mean Flow Fieldmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Flow field characterization of pressurized sooting swirl flames and relation to soot distributions

Geigle

Hadef

Stöhr

et al. 2017

Proceedings of the Combustion Institute

View full text Add to dashboard Cite

show abstract

“…As the gradient was increased, OH values gradually decreased at the tip of the cusps until no OH was present, implying a decrease in the local reaction rate and quenching of the flame front. The formation of cusps is typical of rich iso-octane flames [123][124][125], as Darius Landau hydrodynamic instabilities are enhanced by thermo-diffusive effects [126,127], and lead to the formation of cellular structures [123]. As seen previously in [44], these cusped formations were generally observed in the lower axial regions of the flame where richer mixtures with progressively lower Lewis numbers, Le, were present as the equivalence ratio gradient was increased.…”

Section: Instantaneous Oh Ch 2 O and Heat Release Rate Plif Imagesmentioning

confidence: 65%

Equivalence Ratio Gradient Effects on Local Flame Front Topology and Heat Release Rate in Stratified, Iso-Octane/Air Turbulent V-Flames

Vena¹

View full text Add to dashboard Cite

This thesis details the development and application of an experimental apparatus and methodology capable of quantifying the effects of partial premixing on the local behaviour of turbulent flames. A novel rectangular slot burner was used to generate controlled, transverse variations in mixture strength along its exit plane, such that turbulent, rod-stabilized V-flames could be anchored in reactant mixtures of varying mean gradients in equivalence ratio. A unique windowing approach was devised in which 3-pentanone tracer planar laser induced fluorescence (PLIF) of the reactants was used to determine an analysis region of interest (ROI) within the flame. Iso-contours of equivalence ratio (e.g.  = 0.95-1.05 for nearstoichiometric flame regions) were traced up to the mean position of the flame front to define the width of the ROI, which was specific to each mean  gradient flame condition. This analysis methodology enabled fair comparison among gradient settings, and ensured that any observed variation in local flame behaviour could be attributed specifically to mean  gradient effects, rather than simple mixture strength effects.To all my friends, starting from l

show abstract

Heat release rate variations in a globally stoichiometric, stratified iso-octane/air turbulent V-flame

Vena

Deschamps

Guo

et al. 2015

Combustion and Flame

View full text Add to dashboard Cite

Instabilities and soot formation in high-pressure, rich, iso-octane–air explosion flames1. Dynamical structure

Abstract: This is the unspecified version of the paper.This version of the publication may differ from the final published version. Permanent repository link

Cited by 6 publications

References 21 publications

Flow field characterization of pressurized sooting swirl flames and relation to soot distributions

Flow field characterization of pressurized sooting swirl flames and relation to soot distributions

Equivalence Ratio Gradient Effects on Local Flame Front Topology and Heat Release Rate in Stratified, Iso-Octane/Air Turbulent V-Flames

Heat release rate variations in a globally stoichiometric, stratified iso-octane/air turbulent V-flame

Contact Info

Product

Resources

About