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Gasoline engines employ various mechanisms for improvement of fuel consumption and reduction of exhaust emissions to deal with environmental problems. Direct fuel injection is one such technology. This paper presents a new quasi-dimensional combustion model applicable to direct injection gasoline engine. The Model consists of author's original in-cylinder turbulence and mixture homogeneity sub model suitable for direct fuel injection conditions. Model validation results exhibit good agreement with experimental and 3D CFD data at steady state and transient operating conditions.

One promising solution for increasing vehicle fuel economy, while still maintaining long-range driving capability, is the plug-in hybrid electric vehicle (PHEV). A PHEV is a hybrid electric vehicle (HEV) whose rechargeable energy source can be recharged from an external power source, making it a combination of an electric vehicle and a traditional hybrid vehicle. A PHEV is capable of operating as an electric vehicle until the battery is almost depleted, at which point the on-board internal combustion engine turns on, and generates power to meet the vehicle demands. When the vehicle is not in use, the battery can be recharged from an external energy source, once again allowing electric driving. A series of models is presented which simulate various powertrain architectures of PHEVs. To objectively evaluate the effect of powertrain architecture on fuel economy, the models were run according to the latest test procedures and all fuel economy values were utility factor weighted.

Hybrid powertrain technology, which combines an internal combustion engine and an electric motor as power sources, is penetrating auto markets as a practical approach for reducing vehicle fuel consumption and exhaust emissions. This paper describes the development of an integrated powertrain simulation technology for predicting the fuel economy and exhaust emissions of hybrid electric vehicles with high accuracy and computation speed. Primary paths of kinetic, electric, chemical and thermal energies and their management were modeled. The predicted exhaust emissions and temperatures of the coolant and lubrication oil agreed well with experimental data in various vehicle driving conditions. This simulation was used to study an air-fuel ratio control strategy for reducing NOx at engine restart and to examine an exhaust heat recovery method for reducing fuel consumption and exhaust emissions under cold start conditions.