In order to understand better the auto-ignition process in an HCCI engine, the influence of some important parameters on the auto-ignition is investigated. The inlet temperature, the equivalence ratio and the compression ratio were varied and their influence on the pressure, the heat release and the ignition delays were measured. The inlet temperature was changed from 25 to 70 °C and the equiva...

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...

In recent years, the industry has shifted toward down-sizing and turbo-charging spark ignition (SI) engines in an effort to increase fuel conversion efficiency. However, this has given rise to a destructive phenomenon known as sporadic pre-ignition (SPI). At low cranking speeds and high loads, engines have been observed to knock violently for brief and infrequent intervals. If allowed to contin...

A new combustion model is developed and applied to simulate combustion in dual-fuel engines in which the premixed natural gas is ignited by the combustion flame initiated by a diesel spray. The model consists of a diesel auto-ignition model and a flame propagation model. A G-equation model previously developed to simulate SI engine combustion was incorporated with an auto-ignition model to simu...

Direct numerical simulation (DNS) is used to study auto–ignition of turbulent diffusion flames. A novel, all–Mach number algorithm developed by Doom et al is used. The chemical mechanism is a nine species, nineteen reaction mechanism for H2 and Air from Mueller at el. 2 Simulations of three dimensional turbulent diffusion flames are performed. Isotropic turbulence is superimposed on an unstrain...

The alternative HCCI combustion mode presents a possible means for decreasing the pollution with respect to the conventional gasoline or diesel engines, while maintaining the efficiency of a diesel engine or even increasing it. This paper investigates the possibility of using gasoline in an HCCI engine and analyses the auto-ignition of gasoline in such an engine. The compression ratio that has ...

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 ...

Simulations of forced ignition of non-premixed laminar counterflow flames are used to study the effect of strain rate on ignition success. A one dimensional calculation is performed, using detailed methane chemical kinetics and treating the spark as an instantaneous heat release in an inert mixing layer. Ignition success depends on the mixture composition at the spark location, resulting in lea...

As an attempt at providing insight to develop better modeling strategies for HCCI engines, the ignition and propagation of a reaction front in a premixed fuel/air stream mixed with hotter exhaust gases is computationally investigated using the opposed-flow configuration. The effects of heat and radical transport are studied by imposing various mixing rates on the system. The results show that t...

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 ...