On the Effective Density of Soot Particles in Premixed Ethylene Flames

Wang, Mengda; You, Xiaoqing; Mei, Junyu; You, Xiaoqing

doi:10.1016/j.combustflame.2018.10.004

Cited by 24 publications

(26 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This finding is consistent with the earlier modelling efforts of Kazakov and Frenklach [70], who have employed a "switch-over" diameter in the range of 25 to 30 nm to simulate soot formation considering both coagulation and aggregation. It is also in agreement with a recent experimental study on the effective density of nascent soot particles in a premixed ethylene flame, that suggests an inflection point in the effective density of nascent soot occurs at d m ≈ 20 nm [68]. To explain the inflection point, TEM images were examined in [68], indicating soot morphology changing from spherical-like to non-spherical shapes at d m ≈ 20 nm.…”

Section: 22supporting

confidence: 89%

“…It is also in agreement with a recent experimental study on the effective density of nascent soot particles in a premixed ethylene flame, that suggests an inflection point in the effective density of nascent soot occurs at d m ≈ 20 nm [68]. To explain the inflection point, TEM images were examined in [68], indicating soot morphology changing from spherical-like to non-spherical shapes at d m ≈ 20 nm. In addition, Wang et al [68] analyzed the primary particle size distribution (PPSD) of aggregate particles with d m ≈ 50 nm based on the TEM images.…”

Section: 22supporting

confidence: 89%

“…H p < 0.6 cm), the dominant soot processes are inception, coalescence and surface growth, because the soot particle residence time is too short for them to coagulate and form fractal-like aggregates. Hence, at this stage, the soot particles are nearly spherical, which has been reported by a number of experimental studies [10,[66][67][68]. The near-spherical morphology of nascent soot particles can be used to simplify the modeling work, because the sintering process does not need to be considered under these conditions as there are no aggregates (the sintering rate can be regarded as infinitely fast); thus leaving us fewer free model parameters to investigate.…”

Section: Parametric Sensitivity Analysismentioning

confidence: 86%

“…Due to the lack of experimental data for sub-2.5 nm particles, it is hard to make any inference towards the soot nucleation mechanism using the simulated PSDs. Since a recent experimental work by Wang et al [68] reported that the mass density of nascent soot particles in premixed ethylene flames can be as low as 0.6 g/cm 3 , so four densities (from 0.6 to 1.8 g/cm 3 ) are chosen to perform the sensitivity study. Soot density has an obvious effect on the position of the PSDs as shown in Fig.…”

Section: Flame With H P = 045 CMmentioning

confidence: 99%

“…To explain the inflection point, TEM images were examined in [68], indicating soot morphology changing from spherical-like to non-spherical shapes at d m ≈ 20 nm. In addition, Wang et al [68] analyzed the primary particle size distribution (PPSD) of aggregate particles with d m ≈ 50 nm based on the TEM images. As the flame condition in their work (16% C 2 H 4 ,24% O 2 ,60% AR, cold gas velocity = 7 cm/s (STP), temperature at stagnation plate = 465 K) is very similar to the flame condition that is simulated in this work (16.3% C 2 H 4 ,23.7% O 2 ,60% AR, cold gas velocity = 8 cm/s (STP), temperature at stagnation plate = 511 K), it could be interesting to give more comparison regarding the simulated and measured PPSD.…”

Section: 22mentioning

confidence: 99%

See 4 more Smart Citations

Modelling soot formation in a benchmark ethylene stagnation flame with a new detailed population balance model

Hou

Lindberg

Manuputty

et al. 2019

Combustion and Flame

Self Cite

View full text Add to dashboard Cite

Numerical simulation of soot formation in a laminar premixed burner-stabilised benchmark ethylene stagnation flame was performed with a new detailed population balance model employing a two-step simulation methodology. In this model, soot particles are represented as aggregates composed of overlapping primary particles, where each primary particle is composed of a number of polycyclic aromatic hydrocarbons (PAHs). Coordinates of primary particles are tracked, which enables simulation on particle morphology and provides more quantities that are directly comparable to experimental observations. Parametric sensitivity study on the computed particle size distributions (PSDs) shows that the rate of production of pyrene and the collision efficiency have the most significant effect on the computed PSDs. Sensitivity of aggregate morphology to the sintering rate is studied by analysing the simulated primary particle size distributions (PPSDs) and transmission electron microscopy (TEM) images. The capability of the new model to predict PSDs in a premixed stagnation flame is investigated. Excellent agreement between the computed and measured PSDs is obtained for large burner-stagnation plate separation (≥ 0.7 cm) and for particles with mobility diameter larger than 6 nm, demonstrating the ability of this new model to describe the coagulation process of aggregate particles.

show abstract

Section: 22supporting

confidence: 89%