An Insight into the Effect of Advanced Injection Strategies on Pollutant Emissions of a Heavy-Duty Diesel Engine

Abstract

An advanced numerical investigation has been carried out in order to study the effect of multiple injection strategies on Caterpillar heavy-duty diesel engine emissions. Both different injected fuel percentages for each pulse and several dwells between main and post phase were investigated via computational fluid dynamics (CFD) and large eddy simulation (LES). Two sets of simulations were taken into account for 10% and 20% exhaust gas recirculation (EGR) fractions. In the first one, the main injection was split into two identical phases, while in the second one into three pulses. Within each set, three strategies were considered, increasing the amount of fuel injected during the main and concurrently decreasing the post pulse. Overall, 48 simulations were employed, since four different dwells between the last phase of the main and post injection were considered. Results show that the pollutant emissions minimization has been obtained for the Schemes injecting 65% and 70% of fuel for both two and three split strategies, but for different values of dwell. In fact, emissions very close to each other for NO x and particulate matter have been reached for these cases. Reductions of about −30% and −71% were respectively obtained for NO x and soot in comparison with experimental emissions related to the single injection case.

Numerical Study of the Axial Gap and Hot Streak Effects on Thermal and Flow Characteristics in Two-Stage High Pressure Gas Turbine

“…Deciding the appropriate turbulence model is important for more precise numerical analysis. Direct numerical simulations (DNS) and large eddy simulations (LES) provide a flow database for detailed turbulence statistics, but they require a high computational cost [17][18][19][20][21]. To replace such high-cost models, a Reynolds-average Navier-Stokes (RANS) model (k − ε, k − ω, SST, SST γ etc.…”

Effects of a Dual-Loop Exhaust Gas Recirculation System and Variable Nozzle Turbine Control on the Operating Parameters of an Automotive Diesel Engine

“…In recent years, further developments were considered, starting from the adoption of low pressure (LP) circuit [3,4], as an alternative or coupled to the conventional high pressure (HP) loop [5][6][7]. Other aspects are related to the integration of EGR circuits with the main engine sub-assemblies, such as fuel injection equipment [8,9] and turbocharging systems [10], either in a single-stage configuration fitted with variable nozzle turbine (VNT) [11] or according to two-stage concepts [12]. Moreover, other available cleaning options have to be matched to EGR, such as Miller cycle [13] or advanced combustion processes [14,15], extending its use to the whole range of ICEs, such as in marine and stationary applications.…”

Comparative Analysis of Automotive Products Regarding the Influence of Eco-Friendly Methods to Emissions’ Reduction

“…The increasing use of natural resources and the pollution it causes calls for new ways of addressing automotive customer needs. Owing to the associated complexities and uncertainties, decision makers and planners are facing increased pressure to respond more effectively to several energy-related issues and conflicts, as well as GHG (Greenhouse Gas) emission mitigation within the multiple scales of energy management systems [29][30][31][32].…”