Numerical investigation of soot mass concentration in compression ignition diesel engine

Abstract

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.

The effect of oxygen content in soapnut biodiesel-diesel blends on performance of a diesel engine

“…Both shorter ignition delay and better atomization were responsible for complete combustion and reduced HC emissions. It was also observed that at oxygen percentages higher than 2.37% (blend number [13][14][15][16][17][18], HC emissions were better than those of other fuel blends, with fuel blend number 18 showing the lowest HC emission.…”

“…Moreover, biodiesel is more advantageous in comparison to diesel fuel due to its higher flash point, lower volatility, and greater lubricity [2,[12][13][14][15]. Besides that, biodiesel has a lower aromatic compound content, contains 10%-12% oxygen by weight, and is free of sulphur content.…”

Effective abatement of diesel engine emissions with split injections

“…Subscripts sf and sc, in the above equations, represent soot formed and consumed, respectively. The values of activation energies (represented by Esf and Esc) were taken as 82 X 10 6 and 120 X 10 6 respectively. mfb represents the mass of fuel burnt at every crank angle step and was determined by using the following expression.…”

“…A higher expansion ratio due to high compression ratios in diesel engines leaves low thermal energy to the exhaust, resulting in low fuel consumption and high power output [1,2]. However, diesel engines produce higher levels of nitrogen (NOx) oxides and particulate matter (PM) or soot as compared to their counterpart spark ignition (SI) engines [3][4][5][6]. This is due to diesel engines heterogeneous combustion and thus results in a complex unresolved trade-off between NOx and soot emissions [6][7][8][9].…”

“…However, diesel engines produce higher levels of nitrogen (NOx) oxides and particulate matter (PM) or soot as compared to their counterpart spark ignition (SI) engines [3][4][5][6]. This is due to diesel engines heterogeneous combustion and thus results in a complex unresolved trade-off between NOx and soot emissions [6][7][8][9]. To address this issue, many strategies were evolved and adopted over the past two decades in regard to diesel engine research and manufacturing industry.…”