In this study we summarize and analyze experimental observations of cyclic variability in homogeneous charge compression ignition (HCCI) combustion in a single-cylinder gasoline engine. The engine was configured with negative valve overlap (NVO) to trap residual gases from prior cycles and thus enable auto-ignition in successive cycles. Correlations were developed between different fuel injecti...

An on-the-fly mechanism reduction approach is employed in this paper to integrate detailed chemical kinetics with a computational fluid dynamics (CFD) code. The reduction methodology employs an instantaneous element flux analysis to identify redundant species and reactions for given local conditions. The emphasis of this work is focused on the numerical study of homogeneous charge compression i...

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...

Fuel efficient Homogeneous Charge Compression Ignition (HCCI) engine combustion phasing predictions must contend with non-linear chemistry, non-linear physics, period doubling bifurcation(s), turbulent mixing, combustion deposits, model parameters that can drift day-to-day, and air-fuel mixture state information that cannot typically be resolved on a cycle-to-cycle basis, especially during tran...

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...

T R I B O L O G Y & L U B R I C A T I O N T E C H N O L O G Y W W W . S T L E . O R G wide range of approaches have been undertaken to determine how to reduce emissions from automotive engines. in a previous TLT article, the development of the homogeneous charge compression ignition (hCCi) engine was discussed. When used in place of a conventional gasoline engine, an hCCi engine can produce a 1...

Three-dimensional time-dependent CFD simulations of autoignition and emissions are reported for an idealized engine configuration under HCCI-like operating conditions. The emphasis is on NOx emissions. Detailed NOx chemistry is integrated with skeletal autoignition mechanisms for n-heptane and iso-octane fuels. A storage/retrieval scheme is used to accelerate the computation of chemical source ...

To acquire a high amount of information of the behaviour of the Homogeneous Charge Compression Ignition (HCCI) auto-ignition process, a reduced surrogate mechanism has been composed out of reduced n-heptane, iso-octane and toluene mechanisms, containing 62 reactions and 49 species. This mechanism has been validated numerically in a 0D HCCI engine code against more detailed mechanisms (inlet tem...

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...