Analysis of the Particle Size Distribution in the Cylinder of a Common Rail DI Diesel Engine During Combustion and Expansion

Pungs, Andreas; Pischinger, Stefan; Bäcker, H.; Lepperhoff, Gerhard

doi:10.4271/2000-01-1999

Cited by 22 publications

(17 citation statements)

References 3 publications

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“…In addition, the size distributions in the exhaust are found to be nearly the same as those in the engine cylinder. This result suggests that soot formation and coagulation progresses promptly immediately after the start of combustion, and most of the soot particles in the diesel flame are in the form of aggregates, not in isolated spheres [15]. The mode peak diameters in the distributions are around 100 nm, which is the same order of magnitude as visible wavelengths.…”

Section: Approach To Examine the Spectral Extinction Of Diesel Sootmentioning

confidence: 83%

“…The terms E(m) and F(m)=E(m) included in equation (15) depend generally on the wavelength. As the equation shows, the transmittance t of a cloud of particles is a function of wavelength l only, because other parameters such as fn, k, d p , R g , and D f are all constant for a particular cloud of particles.…”

Section: Results and Discussion Of Light Extinctionmentioning

confidence: 99%

“…The approach employed in this study is to try to account for a = 1:38 discussed in section 2.1 by using equation (15), which is based on the RDG theory. The refractive index m included in E(m) and F(m)=E(m) generally varies with l, and the key is how to treat them.…”

Section: Results and Discussion Of Light Extinctionmentioning

confidence: 99%

“…It is expected from this evidence that particle formation and coagulation of particles occur much quicker in the engine cylinder. The processes of soot formation and oxidation in the engine cylinder were investigated in detail by Pungs et al [15]. They took gas samples from a 2.15 l, Fig.…”

Section: Approach To Examine the Spectral Extinction Of Diesel Sootmentioning

confidence: 99%

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Re-examination of the emissivity of diesel flames

Kamimoto

Murayama

2011

International Journal of Engine Research

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In the Hottel and Broughton equation, the spectral emissivity of soot in flames in the visible wavelength range is characterized by an index α = 1.39, which represents the effect of wavelength on extinction (Hottel and Broughton, 1932). In this study, the spectral specific extinction for diesel soot is examined first by focusing on soot layers sampled on a quartz window from the engine cylinder, and α = 1.38 is obtained. To examine the physics governing the value of α = 1.38, a calculation of spectral extinction is performed using the Rayleigh–Debye–Gans (RDG) theory of soot aggregate scattering with an assumption of constant refractive index. The calculated spectral extinction provides α = 1.31 close to α = 1.38, suggesting that scattering, as well as absorption, contributes largely to the spectral extinction of diesel soot. The attenuation of line-of-sight beam intensity due to out-scattering and the augmentation of the beam intensity as a result of scattering of incoming radiation from other regions are investigated using soot aggregate scattering theory. Based on this approach, a new formula of apparent spectral emissivity εa is proposed, allowing a theoretical explanation of the physical meaning of the KL factor defined in the Hottel and Broughton equation, which has remained vague for many years. Finally the two-colour flame temperature and the KL factor in a production engine are calculated using the new emissivity formula and are compared with those obtained using the conventional emissivity formula. The result shows that the two-colour method using the conventional emissivity formula remains quite useful, and provides values of temperature and KL factor within 1–2 per cent of those obtained with the new emissivity formula.

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Section: Approach To Examine the Spectral Extinction Of Diesel Sootmentioning

confidence: 83%

Section: Results and Discussion Of Light Extinctionmentioning

confidence: 99%

Section: Results and Discussion Of Light Extinctionmentioning

confidence: 99%

Section: Approach To Examine the Spectral Extinction Of Diesel Sootmentioning

confidence: 99%

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Re-examination of the emissivity of diesel flames

Kamimoto

Murayama

2011

International Journal of Engine Research

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“…(1) mean primary particle diameter increases during soot formation and decreases rapidly in the initial soot oxidation phase, followed by gradual decrease to 20 nm in the final stage of soot oxidation; 31,32 (2) a value of d pa ;25 nm was obtained during soot formation phase; 33 (3) a value of d pa = 15-12 nm was obtained in the final stage of soot oxidation phase 8 and (4) mean primary particle size decreased from 18.2 to 12 nm when injection pressure was increased from 70 to 160 MPa. 34 Although the engine type and operating conditions are different, these data indicate that the arithmetic mean particle diameter in soot oxidation process lies in a range of 15 6 5 nm.…”

Section: Primary Soot Particle Diametermentioning

confidence: 99%

Diesel flame imaging and quantitative analysis of in-cylinder soot oxidation

Kamimoto

Uchida²,

Aizawa

et al. 2016

International Journal of Engine Research

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This study concerns a quantitative analysis of late-cycle soot oxidation in diesel engines that focuses on two-dimensional KL factor images obtained by the two-color method. The spatially integrated KL factor was converted into the in-cylinder soot mass using a new formula of diesel soot emissivity. This methodology was applied to two combustion systems: a heavy-duty optical engine which was tuned for a higher fuel-air mixing capability and a rapid compression and expansion machine which had a lower mixing performance. The in-cylinder soot mass history during the last stage of soot oxidation phase was converted into a normalized soot mass history and was used for comparison with simulated soot mass history. A model calculation of in-cylinder soot mass history which was based on oxidation of a primary soot particle was performed with the surface-specific soot oxidation rate as a parameter. A value of the surface-specific soot oxidation rate was specified from the curve fitting approach between the experimental and simulated in-cylinder soot mass traces. The resultant soot oxidation rates plotted on the Arrhenius diagram were found to lie in domains with different oxidation mechanisms. The reason for the scattered plots was discussed referring to model predictions of soot oxidation in the literature, and it was concluded that the higher oxidation rates could be attributed to well-mixed soot oxidizer structure.

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The Process of Formation of Particulate Matter in Combustion Engines

Merkisz

Pielecha

2015

Nanoparticle Emissions From Combustion Engines

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Analysis of the Particle Size Distribution in the Cylinder of a Common Rail DI Diesel Engine During Combustion and Expansion

Cited by 22 publications

References 3 publications

Re-examination of the emissivity of diesel flames

Re-examination of the emissivity of diesel flames

Diesel flame imaging and quantitative analysis of in-cylinder soot oxidation

The Process of Formation of Particulate Matter in Combustion Engines

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