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 ...

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 ...

in this study it has been tried, to compare results and convergence rate of sensitivity analysis and conjugate gradient algorithms to reduce fuel consumption and increasing engine performance by optimizing the timing of opening and closing valves in xu7/l3 engine. in this study, considering the strength and accuracy of simulation gt-power software in researches on the internal combustion engine...

In this study it has been tried, to compare results and convergence rate of sensitivity analysis and conjugate gradient algorithms to reduce fuel consumption and increasing engine performance by optimizing the timing of opening and closing valves in XU7/L3 engine. In this study, considering the strength and accuracy of simulation GT-POWER software in researches on the internal combustion engine...

Advanced combustion modes such as Controlled Auto-Ignition or Homogeneous Charge Compression Ignition have been under much attention due to their ability to reduce both emissions and fuel consumption. Thus, this paper aims at demonstrating the achievement of Controlled Auto-Ignition combustion on a standard 4-cylinder gasoline engine with negative valve overlap (NVO) and analyzing its performan...

in this paper, a numerical study is performed to provide the combustion and emission characteristics resulting from fuel-reactivity controlled compression ignition (rcci) combustion mode in a heavy-duty, single-cylinder diesel engine with gasoline and diesel fuels. in rcci strategy in-cylinder fuel blending is used to develop fuel reactivity gradients in the combustion chamber that result in a ...

Homogeneous Charge Compression Ignition (HCCI) engines are one of the most promising engine technologies for the future of energy conversion from clean, efficient combustion. HCCI engines allow high efficiency and lower CO 2 emission through the use of high compression ratios and the removal of intake throttle valves (like Diesel), and allow very low levels of urban pollutants like nitric oxide...

The lean-burn capability of the Diesel-ignited gas engine combined with its potential for high efficiency and low CO2 emissions makes this engine concept one of the most promising alternative fuel converters for passenger cars. Instead of using a spark plug, the ignition relies on the compression-ignited Diesel fuel providing ignition centers for the homogeneous air-gas mixture. In this study t...

A control oriented engine model is developed to represent a spark ignited engine equipped with a variable cam timing mechanism over a wide range of operating con ditions Based upon laboratory measurements a continuous nonlinear low frequency phenomenological engine model is developed With respect to a xed cam timing engine the VCT mechanism alters the mass air ow into the cylinders the torque r...