Determining fractal properties of soot aggregates and primary particle size distribution in counterflow flames up to 10 atm

Amin, Hafiz M.F.; Bennett, Anthony; Roberts, William L.

doi:10.1016/j.proci.2018.07.057

Cited by 27 publications

(25 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The TEM sampling methodology employed in this work is distinct to thermophoretic sampling commonly used for in-situ particle sampling [2,6,3]. Instead of thermophoresis, the particle deposition here relies on two main physical mechanisms, namely inertial impaction and Brownian diffusion as the sample flow through the holey TEM grid suspended perpendicular to the flow direction.…”

Section: Validation Of Tem Sampling Methodologymentioning

confidence: 99%

“…TEM) is suitable to investigate the particle morphology [33,46] as it reveals the actual structure of particles, albeit as 2D projection. For example, TEM image analysis has been widely used in the combustion community to measure morphological properties of soot, such as aggregate size and fractal dimension [10,2,6,15]. The main challenges with TEM measurements are the sensitivity to the sampling technique [33] and the difficulty in achieving statistically significant sample size.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Detailed characterisation of TiO2 nano-aggregate morphology using TEM image analysis

Manuputty

Lindberg

Botero

et al. 2019

Journal of Aerosol Science

View full text Add to dashboard Cite

A detailed morphological characterisation is performed on flame synthesised TiO 2 nano-aggregates (number of primaries, N < 10) using transmission electron microscopy (TEM) image analysis and mobility measurements. The sizedependent collection efficiency of the TEM sampling method is accounted for with a simple correction for particle deposition through impaction and diffusion. The TEM-derived sizes show excellent agreement with electrical mobility measurements. Primary particle size, aggregate size, and degree of aggregation distributions were obtained for two different flames and varying precursor loading. The analysis reveals some particle aggregation which is likely to occur only very late in the growth stage, leading to the similarity between the primary particle and spherical particle size distributions. The degree of aggregation is defined as the ratio of gyration to spherical equivalent sizes from the projected area analysis, allowing identification of particles with spherical and non-spherical morphologies. The size distributions are found to be strongly affected by precursor loading but not by flame mixture or maximum temperature. In all cases, approximately 60-70% particles are spherical while the rest form small aggregates. The detailed morphological information reported provides the much-needed experimental data for studying the early stage particle formation of TiO 2 from titanium tetraisopropoxide (TTIP) in a well-defined burner configuration.

show abstract

Section: Validation Of Tem Sampling Methodologymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Detailed characterisation of TiO2 nano-aggregate morphology using TEM image analysis

Manuputty

Lindberg

Botero

et al. 2019

Journal of Aerosol Science

View full text Add to dashboard Cite

show abstract

“…Reported k 0 also varies in different studies. Lattuada et al [61] reported a k 0 of 1.17 for diffusion-limited cluster aggregation (DLCA) aggregates; Sorensen [62] show typical fractal aggregates present a k 0 of approximately 1.3; Amin et al [63] obtained a k 0 range of 1.68-1.86 in counterflow flames. However, Liu and Mishchenko [22] demonstrated the optical cross-sections don't change largely as k 0 increases from 0.9 to 2.1, and the variation was below 10%.…”

Section: Shape and Mixing States Of Bcmentioning

confidence: 99%

The Ångström Exponent and Single-Scattering Albedo of Black Carbon: Effects of Different Coating Materials

Luo

Zhang

2020

Atmosphere

View full text Add to dashboard Cite

In this work, the absorption Ångström exponent (AAE), extinction Ångström exponent (EAE), and single-scattering albedo (SSA) of black carbon (BC) with different coating materials are numerically investigated. BC with different coating materials can provide explanations for the small AAE, small EAE ,and large AAE observed in the atmosphere, which is difficult to be explained by bare BC aggregate models. The addition of organic carbon (OC) does not necessarily increase AAE due to the transformation of BC morphologies and the existence of non-absorbing OC. The addition of coating materials does also not necessarily decrease EAE. While the addition of coating materials can increase the total size of BC-containing particles, the effective refractive index can be modified by introducing the coating materials, so increases the EAE. We found that it is not possible to differentiate between thinly- and heavily-coated BC based on EAE or AAE alone. On the other hand, SSA is much less sensitive to the size and can provide much more information for distinguishing heavily-coated BC from thinly-coated BC. For BC with different coating materials and mixing states, AAE, EAE, and SSA show rather different sensitivities to particle size and composition ratios, and their spectral-dependences also exhibit distinct differences. Different AAE and EAE trends with BC/OC ratio were also found for BC with different coating materials and mixing states. Furthermore, we also found empirical fittings for AAE, EAE, SSA, and optical cross-sections, which may be useful for retrieving the size information based on the optical measurements.

show abstract

“…A carbon‐coated 300‐mesh copper grid was assembled on the probe. To avoid the disturbance from the movement of the upstream flame gases during the soot sampling, the sampling probe was made with a length of 40 mm, a width of 4 mm, and a height of 0.3 mm 40 . The details of the sampling probe can be seen in author's previous study 21 .…”

Section: Experimental Methodsmentioning

confidence: 99%

“…To avoid the disturbance from the movement of the upstream flame gases during the soot sampling, the sampling probe was made with a length of 40 mm, a width of 4 mm, and a height of 0.3 mm. 40 The details of the sampling probe can be seen in author's previous study. 21 In general, the sampling probe was composed of two parts: (a) A notch (; ¼ 3, 05 mm) with a depth of 0.1 mm was employed to place the carbon-coated copper mesh at the probe end, and (b) a smaller hole ; ¼ 1:00 ð mm) was used for particle deposition to fix the carbonplated copper mesh and avoid the grid from being vanished during the propelling process.…”

Section: Thermophoretic Sampling Measurementmentioning

confidence: 99%

Experimental studies of soot formation for petro‐ and renewable diesels

Alhikami

Wang

Nugroho

et al. 2022

Intl J of Energy Research

View full text Add to dashboard Cite

Summary The soot formation characteristics of hydro‐processed renewable diesel (HRD), biodiesel, and petroleum diesel were studied in a non‐premixed counter‐flow laminar flame configuration. This investigation is discussed herein in terms of soot morphology, soot volume fraction (SVF), smoke point (SP), and threshold sooting index (TSI) measurements. It was found that both alternative diesel fuels (ie, HRD, and biodiesel) were similar in terms of the soot particle diameter, whereas petroleum diesel was found to exhibit the greatest soot particle formation. Additionally, the soot particle diameter and SVF were both sensitive to the variations of the reactant concentration by as much as 28%, and 86%, respectively. The sooting tendencies of the tested fuels were found to be proportional to their respective aromatic concentrations. In addition, the fuel containing higher hydrogen‐to‐carbon ratio (ie, HRD) had a lower SVF. The TSI indices reported that both HRD and biodiesel had a similar tendency to form soot, and the highest TSI index was petro‐diesel. The SVF has good correlations with the SP results.

show abstract

Determining fractal properties of soot aggregates and primary particle size distribution in counterflow flames up to 10 atm

Abstract: WL (2018) Determining fractal properties of soot aggregates and primary particle size distribution in counterflow flames up to 10atm. Proceedings of the Combustion Institute.

Cited by 27 publications

References 31 publications

Detailed characterisation of TiO2 nano-aggregate morphology using TEM image analysis

Detailed characterisation of TiO2 nano-aggregate morphology using TEM image analysis

The Ångström Exponent and Single-Scattering Albedo of Black Carbon: Effects of Different Coating Materials

Experimental studies of soot formation for petro‐ and renewable diesels

Contact Info

Product

Resources

About

Determining fractal properties of soot aggregates and primary particle size distribution in counterflow flames up to 10 atm

Abstract: WL (2018) Determining fractal properties of soot aggregates and primary particle size distribution in counterflow flames up to 10atm. Proceedings of the Combustion Institute.

Cited by 27 publications

References 31 publications

Detailed characterisation of TiO2 nano-aggregate morphology using TEM image analysis

Detailed characterisation of TiO2 nano-aggregate morphology using TEM image analysis

The Ångström Exponent and Single-Scattering Albedo of Black Carbon: Effects of Different Coating Materials

Experimental studies of soot formation for petro‐ and renewable diesels

Contact Info

Product

Resources

About

Determining fractal properties of soot aggregates and primary particle size distribution in counterflow flames up to 10 atm