Homogeneous charge compression ignition (HCCI) seems to be the most promising solution for gasoline engines in the light of future emissions regulations. This novel combustion technique allows for significant reduction of fuel consumption and engine-out NOX emissions at low and medium engine load/speed conditions. High heat release rate enables realization of the Otto cycle close to ideal, incr...

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...

homogenous charge compression ignition (hcci) engines hold promise of high fuel efficiency and low emission levels for future green vehicles. but in contrast to gasoline and diesel engines, hcci engines suffer from lack of having direct means to initiate combustion. a combustion timing controller with robust tracking performance is the key requirement to leverage hcci application in production ...

the preparation of air–fuel mixture is considerably dependent on fluid flow dynamics to achieve improved performance, efficiency, and engine combustion in the appearance of flow. in this study, the effects of mixtures of hydrogen and compressed natural gas (cng) on a spark ignition engine are numerically considered. this article presents the results of a direct-injection engine using methane–hy...

The Internal Combustion (IC) Engine is perhaps the most wide-spread apparatus for transforming liquid and gaseous fuel to useful mechanical work. Homogeneous charge compression ignition (HCCI) is a new combustion technology that may develop as an alternative to diesel engines with high efficiency and low NOx and particulate matter emissions. The homogenous charge compression ignition (HCCI) is ...

In low ambient temperatures the engine will have poor output torque and power generation at the first cycles of its performance, long start time and huge noxious emissions because of insufficient temperature and quality of air-fuel mixture and failure of flame to burn the charge. It is noted that any attempt to increase the charge temperature leads to better combustion conditions. By applying t...

The preparation of air–fuel mixture is considerably dependent on fluid flow dynamics to achieve improved performance, efficiency, and engine combustion in the appearance of flow. In this study, the effects of mixtures of hydrogen and compressed natural gas (CNG) on a spark ignition engine are numerically considered. This article presents the results of a direct-injection engine using methane–hy...

Experimental research has been conducted on the effect of ignition timings characteristics and performance gasohol engines such as power, torque, specific fuel consumption, thermal efficiency. The used in this is pure gasoline a mixture 50% bioethanol (BE50). results show that timing gives maximum occurs at top bottom dead points 9 degrees for 12 BE50 fuel. Furthermore, power obtained 6,500 rpm...

conventional compression ignition (ci) engines are known for their high thermal efficiency compared to spark ignited (si) engines. gasoline because of its higher ignition delay has much lower soot emission in comparison with diesel fuel. using double injection strategy reduces the maximum heat release rate that leads to nox emission reduction. in this paper, a numerical study of a gasoline fuel...

The effect of variable water injection timing on performance and emission characteristics of hydrogen fueled compression ignition (HFCI) engine has been investigated and the results are presented in this paper. In this study, water is injected from 20 BTDC to 20 ATDC with injection duration of 20 CA and 40 CA. Hydrogen is injected at the intake port with fixed injection timing from 0 CA to 40 C...