Surface morphology and inner fractal cutoff scale of spherical turbulent premixed flames in decaying isotropic turbulence

Kulkarni, Tejas; Bisetti, Fabrizio

doi:10.1016/j.proci.2020.06.117

Cited by 14 publications

(3 citation statements)

References 12 publications

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“…The fractal model predicts the wrinkled flame surface based on the fractal nature of the flame morphology, as discussed elsewhere. 21,56,57,[70][71][72][73] More precisely, it presumes the recursive self-similarity of the flame geometry within the length scales ranging between the outer and inner cutoffs. In the context of the fractal model, the general expression for the wrinkled flame surface is given as…”

Section: Determination Of Turbulent Flame Speedmentioning

confidence: 99%

“…It is worth noting that equation (39) exhibits a similar structure to the term l t / ε c in equation (38) when the integral length scale l t is equivalent to the outer cutoff scale. Most importantly, the reported values of the exponent ( D 3 − 2 ) (or in a two-dimensional analysis, ( D 2 − 1 ) ) in the literature 21,56,57,70–72 range typically from 0.2 to 0.5, despite a wider range being reported at extremely high Ka conditions. 73 Therefore, it is worth highlighting that the previous analysis of C 2 is consistent with the fractal analysis.…”

Section: Development Of the 0d Combustion Modelmentioning

confidence: 99%

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A universally applicable 0D combustion model with a novel analysis of the critical factors affecting combustion in spark-ignition engines

Kim

Song

2023

International Journal of Engine Research

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Notwithstanding the continuous technological development of spark-ignition engines, the physics of in-cylinder phenomena has not been explicitly clarified to date. Furthermore, the advent of diverse engine technologies and in-cylinder compositions has increased the difficulty of understanding these phenomena using existing analysis methods. Under those circumstances, the modeling based on the fundamental combustion behaviors is becoming critical for analyzing combustion. Built upon the zero-dimensional flame surface density model, therefore, the models proposed herein attempt to reproduce a vast majority of combustion behaviors revealed to date, such as differential diffusion, thermo-diffusive instability, cutoff scales, distributed reaction, and flame quenching. As a result, we successfully predicted the combustion of numerous operating points of four different SI engines, including the extremely lean operating points of gasoline/air mixture up to [Formula: see text]. Furthermore, the extensive thermodynamic ranges are explored for the validation of the models with the aid of continuously variable valve timing modules; the pressure and the calculated temperature of the unburned mixture at ignition timing are varied from 4.5 to 28.6 bar and 559–794 K, respectively. In this study, we suggest an expression for a fully-developed turbulent flame speed well-fitted with the explored ranges of chemical and thermodynamic states by inspecting the influencing factors for flame wrinkling. Additionally, we analyze combustion using the developed models and identify several distinctive features of both stoichiometric and lean-burn points. Lastly, this study reveals the importance of flame thickness (or inner cutoff), which has a comparable or more severe effect on early flame propagation compared to planar laminar flame speed.

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Section: Determination Of Turbulent Flame Speedmentioning

confidence: 99%

Section: Development Of the 0d Combustion Modelmentioning

confidence: 99%

A universally applicable 0D combustion model with a novel analysis of the critical factors affecting combustion in spark-ignition engines

Kim

Song

2023

International Journal of Engine Research

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“…As shown in Figure 1, the combustion characteristics of hydrocarbon fuel mainly include the following three points: 1. Flame morphology [16,17] ; 2. Flame temperature [18] ;3.…”

Section: Introductionmentioning

confidence: 99%

Experimental study on soot characteristics of laminar co-flow ethylene diffused flame under air atmosphere

Jiang

Liang

et al. 2021

E3S Web Conf.

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The morphological characteristics of ethylene flame under different working conditions were photographed and analyzed by CCD camera, the temperature distribution at different positions of flame was measured and analyzed by the thermocouple, and the characteristics of soot in ethylene diffusing flame under different airflow rates were studied by means of SiC fiber sampling and subsequent TEM image analysis. The results showed that: (1) when the airflow was unchanged, the flame height increased with the increase of ethylene flow, and the flame height changed with the increase of ethylene flow in a linear relationship. When the ethylene flow increased from 120 mL/min to 180 mL/min, the flame height increased by about 60%. The flame height increased slightly with the increase in air flow. (2) The flame edge temperature was always greater than the central temperature of the corresponding height. Under the same working condition, the average temperature was 87.5 °C higher. (3) Along the flame axis, soot particles follow the process of nucleation, growth, condensation, agglomeration, and oxidation, and the four processes coexist. Once the flow rate of ethylene is determined, the generation of soot in each stage will lag when the flow rate of air increases.

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Modeling of combustion and turbulent jet diffusion flames in fractal dimensions

El-Nabulsi

Anukool

2022

Continuum Mech. Thermodyn.

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Surface morphology and inner fractal cutoff scale of spherical turbulent premixed flames in decaying isotropic turbulence

Cited by 14 publications

References 12 publications

A universally applicable 0D combustion model with a novel analysis of the critical factors affecting combustion in spark-ignition engines

A universally applicable 0D combustion model with a novel analysis of the critical factors affecting combustion in spark-ignition engines

Experimental study on soot characteristics of laminar co-flow ethylene diffused flame under air atmosphere

Modeling of combustion and turbulent jet diffusion flames in fractal dimensions

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