Study on Soot Mass Fraction and Size Distribution in a Direct Injection Diesel Engine Using Particulate Size Mimic Soot Model

Abstract

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.

Impact of thermophoresis factor on soot particle trajectories near the in-cylinder wall in a diesel engine

“…The overall velocity vector earned at that particular moment is demonstrated by this output only. Starting from the selected crank angle until the end of the simulation, MATLAB R2013a Software, a routine using in-house programming code was developed to track the movement and trajectory of each soot particles (Örs et al 2018;Ibrahim et al 2017;Andi et al 2019;Ibrahim et al 2018).…”

“…CFD data such as velocity, pressure, temperature, mass, and soot number density obtained are the specific data located at each cell node calculated by CONVERGE v2.2 software. Soot formation analysis using the software has been conducted and reported by Ibrahim et al (2018). Using RK4 Method for evaluation, location of particles does not seem to be at original node as it was produced when performing prediction of particle trajectories.…”