Soot particles, carbon monoxide, oxides of nitrogen, oxides of sulphur, and hydrocarbon are the emissions produced from diesel engine combustion. Those emissions species are undesirable since they give detrimental impacts to the atmosphere and human well-being. Several numerical investigations conducted by various researchers provide different soot mass concentration values. As an alternative, this study was carried out to investigate the soot mass level produced by a single cylinder diesel engine, using a commercial multidimensional computational fluid dynamic software. The result obtained from simulation effort was then validated by experimental testing during the same engine condition (engine speed of 1600 rpm at 40% load). Soot mass predicted by simulation gives a value of 3.43 × 10 -8 kg at end of simulation, while measured soot mass via experimental testing gives a value of 1.52 × 10 -8 kg. Both results differ by 56% thus indicating that the simple soot model applied was not sufficient to represent the actual soot mass emitted through exhaust manifold. This leads to the conclusion that more detailed soot model is needed to make the simulation results more meaningful and comparable to the experimental testing.

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This review article describes a list of most common techniques of soot measurement, particularly for in-cylinder diesel engine soot. The techniques presented in this paper are Laser Induced Incandescence (LII), Light/Laser Extinction Measurement (LEM), Light/Laser Scattering Measurement (LSM), Emission Tomographic (ET) and Thermophoretic Sampling. All techniques are briefly elaborated and their principles of operation, as well as their applications and current issues, are covered. It is commonly acknowledged that non-invasive techniques feature some advantages and are more preferable compared to invasive techniques. Besides, more modern technique such as ET is said to be most widely applied in the future due to its high level of accuracy. However, there are possibilities that both invasive and non-invasive methods can complement each other to obtain more accurate soot measurements.

Abstract.Research via computational method, specifically by detailedkinetic soot model offers much more advantages than the simple model as more detailed formation/oxidation process is taken into consideration, thus providing better soot mass concentration, soot size, soot number density as well as information regarding other related species. In the present computational study, investigation of in-cylinder soot concentration as well as other emissions in a single cylinder diesel engine has been conducted, using a commercial multidimensional CFD software, CONVERGE CFD. The simulation was carried out for a close-cycle combustion environment from inlet valve closing (IVC) to exhaust valve opening (EVO). In this case, detailed-kinetic Particulate Mimic (PM) soot model was implemented as to take benefit of the method of moment, instead of commonly implemented simple soot model. Analyses of the results are successfully plotted to demonstrate that the soot size and soot mass concentration are strongly dependent on the detailed soot formation and oxidation process rates. The calculated of soot mass concentration and average soot size at EVO provide the end value of 29.2 mg/m 3 and 2.04 x 10 -8 m, respectively. Besides, post-processing using EnSight shows the qualitative results of soot concentration along simulation period in the combustion chamber.

With today's computing technology, research on soot particles using simulation works has become more preferable as a supplementary to the existing experimental methods. The objective of this study is to investigate the effect of different engine load conditions to in-cylinder soot particles formation. This is to clarify the relationship between soot mass fraction (SMF) and size distribution. The first section of the study is conducted by computational analysis using a detailed kinetics soot model, particulate size mimic (PSM), which is based on the concept of the discrete sectional method. The analysis is carried out within closed-cycle combustion environment which is from the inlet valve closing (IVC) to the exhaust valve opening (EVO). The next section is conducted by experimental work deliberately for validation purpose. The total soot mass obtained from the computational work during EVO is comparable to the calculated value by less than 13% error for all of the experimental cases. The soot size distribution measurement indicates that exhaust out particles are dominantly in the dual-mode size range, <10 nm and 11–30 nm. The relationship between the soot mass and size distribution demonstrates that soot mass fraction does not completely rely on soot size distribution as well as particle size range. In most of the cases, particles with the moderate size range (11–60 nm) hold the highest mass fraction during EVO. On the whole, this paper provides significant information that contributes key knowledge to indicate that soot mass fraction is not entirely dependent on soot size distribution as well as particle size range.