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...

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...

This paper presents a model of an electric variable valve timing (EVVT) system and its closed-loop control design with experimental validation. The studied EVVT uses a planetary gear system to control the engine cam timing. The main motivation of utilizing the EVVT system is its fast response time and the accurate timing control capability. This is critical for the combustion mode transition co...

Homogeneous Charge Compression Ignition (HCCI) is an advanced combustion strategy that able to reduce nitric oxides (NOx) emissions and increase fuel efficiency simultaneously. This study investigated the effects of premixed kerosene fuel on the auto-ignition characteristics in a light-duty compression ignition engine. A partial HCCI engine was modified from a single cylinder, four-stroke, dire...

Homogeneous charge compression ignition (HCCI) is an advanced combustion concept that is developed as an alternative to diesel engines with higher thermal efficiency along with ultralow NOx and PM emissions. To study the performance of this novel technique, experiments were performed in a two cylinder engine, in which one cylinder is modified to operate in HCCI mode while other cylinder operate...

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...

At present, it is highly required from the automobile sector to develop clean technologies with lower fuel consumption for ambient air quality improvement, green house gas reduction and energy security. Furthermore, due to continuously stringent emission legislation and the fast depletion of the primary energy resources, the development of new highly efficient and environment friendly combustio...

This thesis deals with numerical simulations of the turbulent combustion process in Homogeneous Charge Compression Ignition (HCCI) engines. An accurate and computationally efficient Large Eddy Simulation (LES) model was developed and used throughout this thesis to investigate the development of in-cylinder turbulence, temperature stratification, onset of auto-ignition, and development of the re...

in this paper, the performance of a natural gas hcci engine is studied through a thermodynamic model including detailed chemical kinetics. it is shown that as hydroxyl radical has important effects on natural gas combustion, it is possible to quantify soc with hydroxyl concentration variations. meanwhile the influence of using formaldehyde as an additive on the engine characteristics has been i...

Homogenous Charge Compression Ignition (HCCI) is a mode of combustion in IC engines in which premixed fuel and air are ignited spontaneously. There is a belief that HCCI engines have a great potential to improve fuel consumption and reduce NOx emissions. In this study, a single zone, zero dimensional, thermo-kinetic model has been developed and a computer program with MATLAB software is use...