Cyclic variability (CV) in lean HCCI combustion at the limits of operation is a known phenomenon, and this work aims at investigating the dominant effects for the cycle evolution at these conditions in a multi-cylinder engine. Experiments are performed in a four-cylinder engine at the operating limits at late phasing of lean HCCI operation with negative valve overlap (nvo). A combustion analysi...

This paper presents a pre-mixed combustion model for diesel and Jatropha oil blends combustion studies. Jatropha oil blends are considered as a mixture of diesel and Jatropha oil. CFD package, FLUENT 6.3 is used for modeling the complex combustion phenomenon in compression ignition engine. The experiments are carried out on a single cylinder, four strokes, water cooled direct injection compress...

The study investigates the effect of aluminium oxide nanoparticles as an additive to Madhuca Indica (mahua) methyl ester blends on performance, emission analysis of a single-cylinder direct injection diesel engine operated at a constant speed at different operating conditions. The test fuels are indicated as B10A0.2, B10A0.4, B20A0.2, B20A0.4 and diesel respectively. The results indica...

In this study, mustard biodiesel (B100) was produced from low quality crude mustard oil and tested in a four-cylinder, direct-injection, diesel engine to investigate the combustion, performance and emission characteristics of the engine at different engine speeds and full load conditions. Biodiesel and its blends showed increased peak cylinder pressure and reduced ignition delay when compared t...

In a turbocharged engine, preserving the maximum amount of exhaust pulse energy for turbine operation will result in improved low end torque and engine transient response. However, the exhaust flow entering the turbine is highly unsteady, and the presence of the turbine as a restriction in the exhaust flow results in a higher pressure at the cylinder exhaust ports and consequently poor scavengi...

Natural gas-diesel dual fuel combustion is a beneficial strategy for achieving high efficient and low emissions operation in compression ignition engines, especially in genset application heavy duty diesel engine at rated power. This study aims to investigate a dual fuel engine performance and emissions using premixed natural gas and early direct injection of diesel fuel. Due to the different r...

CFD Aided Development of a SI-DI Engine — Gasoline Direct Injection (GDI) appears to be the most relevant way to improve fuel efficiency of SI engines. But today, GDI is essentially regarded as a suitable technology for relatively high displacement engines, and the literature shows that the R&D effort on GDI engines is generally made for bores larger than 80 mm. For small bore engines (bore bel...

One of the main controlling parameters in diesel engine combustion is the fuel – air mixing process that has direct effects on engine performance and pollutant emissions, reviewing over previous literature showed that split injection strategies could satisfy this purpose very well. For the first time and in this paper, pilot and double injection strategies were combined and formed new triple in...

With a view to understanding the air-fuel mixing behavior and the effects of the mixture quality on the emissions formation and engine performance, a new quantitative factor of the in-cylinder air-fuel homogeneity named Homogeneity Factor (HF) has been developed. Its characteristics under various injection conditions and air swirl motions within the cylinder have been investigated with CFD simu...