By modulating engine valves to reinduct hot exhaust gas together with air and fuel, a clean and efficient form of autoignition can be created. Control of this combustion process, known as homogeneous charge compression ignition (HCCI), requires not only precise valve control but also a combustion control strategy that accounts for the cycle-to-cycle coupling through the exhaust. This paper outl...

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 ...

Towards a Stronger Simulation Support for Engine Control Design: a Methodological Point of View — Thanks to a specific crank angle degree modelling approach and to an accurate simulator calibration, it is nowadays possible to build a complete simulator which allows the control engineer to access to numerous engine variables, especially non measurable values, and to perform tests over a wide ran...

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...

Lean fuel/air mixtures with various fuel/fuel ratios between methane and n-butane were supplied to a premixed compression-ignition engine (i.e. homogeneous charge compression ignition engine, HCCI) with or without supplementary gaseous formaldehyde induction as an ignition controlling additive. In the no additive case the methane and butane function as the two fuels in the high/low-octane two-f...

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...