This paper presents a modeling study of a CNG Homogenous Charge Compression Ignition (HCCI) engine using single-zone and multi-zone combustion models. Authors' developed code could be able to predict engine combustion and performance parameters in closed part of the engine cycle. As detailed chemical kinetics is necessary to investigate combustion process in HCCI engines, therefore, GRI-m...

in this study, a numerical simulation using the cfd software, fluent, has been conducted to examine the effect of various shapes of the venturi component sections in order to find the optimum venturi specifications to increase the egr rate with minimum pressure loss at the part load operation range. the cfd results reveal that the venturi should be precisely optimized to introduce the required ...

Air pollution is one of the major issues about the diesel engines in todays' world. It is a special concern in those areas that have difficulty meeting health-based outdoor air quality standards. Natural gas has low emission and resource abundance and also conventional compression ignition engine can be easily converted to a dual fuel mode to use natural gas as main fuel and diesel as pilot ...

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...

current approaches to the analysis of internal combustion engines are no longer merely based on the first law of thermodynamics and are conducted from the second law either. the evaluation of processes by the first law cannot provide a sophisticated insight into the issue. so, due to the necessity of having a detailed perspective of the losses in different thermodynamic processes, a useful meth...

homogenous charge compression ignition (hcci) combustion is spontaneous multi-site combustion of a nominally premixed air/fuel mixture that exhibits high rate of pressure rise and short combustion duration. to avoid excessive pressure rise rate and knocking, hcci engines are fueled with highly diluted mixture using a combination of excess air and/or egr. hcci combustion is attractive due to ext...

This paper documents the application of exhaust gas fuel reforming of two alternative fuels, biodiesel and bioethanol, in internal combustion engines. The exhaust gas fuel reforming process is a method of on-board production of hydrogen-rich gas by catalytic reaction of fuel and engine exhaust gas. The benefits of exhaust gas fuel reforming have been demonstrated by adding simulated reformed ga...

Gas motion within the cylinder is one of the major factors that control the combustion process in spark ignition engine. It also has significant impact on heat transfer. Both the bulk gas motion and the turbulence characteristics of the flow are important and governing the overall behavior of the flow. An arrangement for obtaining a stratified charge, using port injection, is proposed for a ...