This paper simulates the density and temperature fields in the process of mixture formation with two combustion modes in a Diesel engine. The computational simulations and experiments show that in the normal combustion mode, the density and temperature of mixtures change greatly in the combusting sprays so that there are premixed combustion and diffusion combustion simultaneously, which results...

The HCCI combustion process is initiated due to auto-ignition of fuel/air mixture which is dominated by chemical kinetics and therefore fuel composition has a significant effect on engine operation and a detailed reaction mechanism is essential to analysis HCCI combustion. A single zone-model permits to have a detailed chemical kinetics modeling for practical fuels. In this study a single-zone ...

Problem statement: This study describes the use of Reformer Gas (RG) to alter NOx emission in a CNG-fueled HCCI engine. Comparison with diesel, natural gas has a very high octane number (≈120) and high auto-ignition temperature (≈600°C). Composed mostly of methane, natural gas is the only common fuel to manifest relatively pure, single-stage combustion. Other fuels have stronger low-temperature...

the hcci combustion process is initiated due to auto-ignition of fuel/air mixture which is dominated by chemical kinetics and therefore fuel composition has a significant effect on engine operation and a detailed reaction mechanism is essential to analysis hcci combustion. a single zone-model permits to have a detailed chemical kinetics modeling for practical fuels. in this study a single-zone ...

homogeneous charge compression ignition (hcci) combustion is a pioneer method of combustion in which pre-mixed fuel and oxidizer (typically air) are compressed to the point of auto-ignition. hcci engines can operate with most alternative fuels, especially, dimethyl ether (dme) which has been tested as a possible diesel fuel due to its simultaneously low nox and pm emissions. in this paper a sin...

The parameters that are present in Exhaust Gas Recirculation (EGR) are believed to provide an important contribution to control the auto-ignition process of the Homogeneous Charge Compression Ignition (HCCI) in an engine. For the investigation of the behaviour of the autoignition process, a kinetic multi-component mechanism has been developed in former work, containing 62 reactions and 49 speci...

The Homogeneous Charge Compression Ignition (HCCI) combustion concept lacks direct ignition timing control, instead the auto ignition depends on the operating condition. Since auto ignition of a homogeneous mixture is very sensitive to operating conditions, a fast combustion timing control is necessary for reliable operation. Hence, feedback is needed and the crank angle of 50% burnt (CA50) has...

In this study, the effect of second injection timing on the combustion and emissions characteristics of a direct injection HCCI gasoline engine was investigated by using ethanol and methanol blended gasoline fuel. For this aim, a diesel engine was converted to an electronically controlled HCCI gasoline engine. The injection timings and fuel quantity for each injection were adjusted to get desir...