ABSTRACT Stringent NOx and particulate emission constraints require high levels of exhaust gas recirculation. In this paper we model and analyze a Variable Valve Timing methodology that in steady-state achieves large levels of internal Exhaust Gas Recirculation (iEGR) or residual charge in Compression Ignition Direct Injection (CIDI) engines. Current external Exhaust Gas Recirculation (eEGR) te...

The tests were carried out with the spark timing adjusted to the maximum brake torquetiming in various equivalence ratios and engine speeds for gasoline and natural gas operations. In thiswork, the lower heating value of gasoline is about 13.6% higher than that of natural gas. Based on theexperimental results, the natural gas operation causes an increase of about 6.2% brake special fuelconsumpt...

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...

Nowadays, ceramic exhaust gas sensors are installed in quantities of millions in automotive exhaust gas systems. Almost any automobile being powered by a gasoline combustion engine is equipped with at least one zirconia exhaust gas oxygen sensor (l probe) for detection of the air-to-fuel ratio l. The first part of this short overview focuses on potentiometric as well as on amperometric zirconia...

in this study a heat exchanger is designed for cooling exhaust gas and an experiment is carried out to investigate the effect of exhaust gas recirculation (egr) temperature on destruction of the fuel’s availability due to combustion processes in idi diesel engine cylinder. to serve this aim an exergy analysis is conducted on the engine cylinder which provides all the availability terms by which...

The effects of spark timing and exhaust valve timing change on exhaust gas temperature during cold start of an SI engine are studied through engine bench tests. It is observed that the exhaust gas temperature increases when the spark timing and valve timing are retarded individually or simultaneously, due to late combustion or slow flame speed. However, using COVimep it is also investigated tha...

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...

In this research, a new exhaust manifold and its cooling jackets is first designed for the integrated exhaust manifold into cylinder head (IEMCH) for a turbocharged engine. Then, the gas exchange and flow analysis is carried out numerically to evaluate the proper conditions for the exhaust gas and the coolant stream respectively. Finally, the entire engine parts are thermally analyzed to assure...

This paper presents an experimental investigation of various exhaust gas recirculation (EGR) rates on the engine performance like brake thermal efficiency, brake specific fuel consumption and brake power and engine exhaust gas emission parameters like nitrogen oxides(NOx), carbon monoxide (CO), hydrocarbon(HC) and particulate matter (PM) for the fuel used in the engine. Four observations are ma...