Puffing-enhanced fuel/air mixing of an evaporating -decane/ethanol emulsion droplet and a droplet group under convective heating

Shinjo, Junji; Xia, Jun; Ganippa, Lionel; Megaritis, A.

doi:10.1017/jfm.2016.130

Cited by 30 publications

(23 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Jump conditions [9,10] are used to compute the heat, momentum and mass transfer across an interface. The details can be found in [11,12,13,14].…”

Section: Governing Equationsmentioning

confidence: 99%

“…After-puffing ligament ejection and secondary droplet pinch-off Ethanol vapour Puffing of an ethanol-in-decane emulsion droplet under convective heating [13]. N nuclei is the number of initial nuclei.…”

Section: Ejection Holementioning

confidence: 99%

“…. Doubly conditioned mean scalar dissipation rate χ in strong puffing with ejections of liquid-fuel ligaments [13]: (a) See Fig. 8 for variable definitions.…”

Section: Ejection Holementioning

confidence: 99%

“…At 1 MPa, the boiling temperature of Figure 10. Puffing-enhanced micro-mixing [13]. (a) χ 1 |Z 1 ; (b) budget analysis on χ 1 |Z 1 using Eq.…”

Section: Puffing-enhanced Fuel/air Mixing [13]mentioning

confidence: 99%

See 3 more Smart Citations

Microexplosion and Puffing of an Emulsion Fuel Droplet

Xia

Shinjo²

2017

Proceedings ILASS–Europe 2017. 28th Conference on Liquid Atomization and Spray Systems

View full text Add to dashboard Cite

Microexplosion is rapid disintegration of an emulsion droplet caused by explosive boiling of embedded liquid subdroplets with a lower boiling point. Microexplosion and puffing (partial microexplosion) are potentially beneficial to achieving enhanced secondary atomisation. These eruptive secondary atomisation mechanisms will help to meet conflicting requirements for an atomising fuel spray with regard to penetration achieved by large droplets and evaporation/mixing achieved by small droplets.Although with great interest, our understanding of microexplosion is still limited and therefore optimising and controlling microexplosion is not feasible yet. This paper reviews our recent research outcome on microexplosion and puffing of an emulsion fuel droplet from high-fidelity interface-capturing simulation study, which directly resolves the dynamics of boiling and evaporating liquid/gas interfaces, immiscible liquid/liquid interfaces with jump conditions for mass, momentum and heat transfer across a resolved interface.We first unveiled microexplosion and puffing dynamics of an emulsion fuel droplet in a quiescent ambient. Since convective heating has important effects on temperature distribution inside a fuel droplet in realistic engine conditions, which determines the initial nucleation location and thus the microexplosion outcome, a model has been proposed to approximate the temperature distribution inside a droplet, for which momentum and heat transport was found to be only moderately correlated under typical engine conditions. With this model in place that allows for saving considerable computational cost on setting up initial conditions for microexplosion simulation, puffing effects on fuel/air mixing is then investigated, which can be quantified by the scalar dissipation rate (SDR) of the primary fuel decane, the SDR of the secondary fuel ethanol and the cross SDR. We then further extended our simulation studies towards reacting conditions and investigate puffing effects on a droplet wake flame.The series of high-fidelity simulation studies is believed to have considerably improved our understanding of microexplosion dynamics and impact on local fuel/air mixing and combustion. Based on the improved knowledge, microexplosion induced secondary droplet breakup models can be developed and incorporated into hybrid highfidelity simulation of spray atomisation and combustion enhanced by microexplosion. KeywordsMicroexplosion; Puffing; Emulsion droplet; Mixing; Droplet combustion. IntroductionLiquid-fuel spray atomisation and combustion is widely used in combustion engines. For engines, fuel efficiency is critical and emission regulations are more and more stringent. Using emulsion fuels, which can be water-in-oil or biofuel-in-fossil-fuel emulsions, can be an effective way to enhance fuel efficiency and reduce emissions. Emulsion fuel is an immiscible liquid mixture with sub-droplets dispersing in the primary liquid fuel. If physical properties such as the boiling point are distinctly different between the two i...

show abstract

“…Jump conditions [9,10] are used to compute the heat, momentum and mass transfer across an interface. The details can be found in [11,12,13,14].…”

Section: Governing Equationsmentioning

confidence: 99%

Section: Ejection Holementioning

confidence: 99%

“…. Doubly conditioned mean scalar dissipation rate χ in strong puffing with ejections of liquid-fuel ligaments [13]: (a) See Fig. 8 for variable definitions.…”

Section: Ejection Holementioning

confidence: 99%

“…At 1 MPa, the boiling temperature of Figure 10. Puffing-enhanced micro-mixing [13]. (a) χ 1 |Z 1 ; (b) budget analysis on χ 1 |Z 1 using Eq.…”

Section: Puffing-enhanced Fuel/air Mixing [13]mentioning

confidence: 99%

See 2 more Smart Citations

Microexplosion and Puffing of an Emulsion Fuel Droplet

Xia

Shinjo²

2017

Proceedings ILASS–Europe 2017. 28th Conference on Liquid Atomization and Spray Systems

View full text Add to dashboard Cite

show abstract

“…[26,27,28]. The other approach fully-resolves the liquid phase with the limitation of only simulating a few tiny droplets [29,30,31,32,33].…”

Section: Introductionmentioning

confidence: 99%

Identification of local extinction and prediction of reignition in a spark-ignited sparse spray flame using data mining

Wandel

2018

Combustion and Flame

View full text Add to dashboard Cite

Direct Numerical Simulations (DNS) of droplet fields which are ignited using a spark are investigated to deduce any behaviour that distinguishes between the cases where successful flame propagation occurs and where a flame ignites but subsequently extinguishes. At the instant the spark was deactivated, some of the studied cases displayed no local extinction, others showed some local extinction (one with reignition and the rest with global extinction) and the rest showed global extinction. The gaseous field at this instant was analysed using the data mining technique the Gaussian Mixture Model on each case separately; this method groups data points, enabling distinction between the various behaviours. The results from this analysis showed that in the case with local extinction-reignition, the regions of space near the flame kernel which produced local quenching were caused by evaporating droplets. These regions of local quenching were relatively small compared to the strong flame front surrounding them; the regions of local quenching were also relatively far from the centre of the flame kernel. In contrast, in cases with local then global extinction, the droplets created regions which were extensions of the relatively-small flame front, and these regions behaved in a similar manner to the flame propagation. As a consequence, these cases were unable to support a self-sustaining flame. Such distinctive behaviour promises opportunities to detect situations where global extinction is imminent and implement appropriate control strategies to prevent global extinction.

show abstract

Processes in Composite Droplets

Sazhin

2022

Mathematical Engineering

View full text Add to dashboard Cite

Puffing-enhanced fuel/air mixing of an evaporating -decane/ethanol emulsion droplet and a droplet group under convective heating

Cited by 30 publications

References 64 publications

Microexplosion and Puffing of an Emulsion Fuel Droplet

Microexplosion and Puffing of an Emulsion Fuel Droplet

Identification of local extinction and prediction of reignition in a spark-ignited sparse spray flame using data mining

Processes in Composite Droplets

Contact Info

Product

Resources

About