Introduction In order to overcome the pollutant emission limitations the use of homogeneous charge compression ignition (HCCI) mode must be considered in direct injection diesel engine using biodiesel fuel. HCCI mode reduces PM and NOx emissions without penalize the performances [1]. This occurs because the combustion develops with low temperature and burns a premixed air/fuel mixture. Biodiese...

This paper is concerned with the Residual Gas Fraction measurement and estimation on a Homogeneous Charge Compression Ignition (HCCI) engine. A novel incylinder gas sampling technique was employed to obtain cyclic dynamic measurements of CO2 concentration in the compression stroke and in combination with CO2 concentration measurements in the exhaust stroke, cyclic Residual Gas Fraction was meas...

A large eddy simulation (LES) model was developed to simulate the combustion process in a spark-assisted homogeneous charge compression ignition (SACI) engine. First, an ignition and flame propagation model based on a reaction progress variable is presented. The reaction progress variable is defined based on the normalized cumulative heat release. Transport equation for the progress variable is...

Homogeneous charge compression ignition (HCCI) combustion enables higher thermal efficiency and lower NOx emission to be achieved in internal combustion engines compared to conventional combustion systems. A new concept HCCI engine system fueled with dimethyl ether (DME) with a high cetane number and methanol-reformed gas (MRG) with high anti-knock properties has been proposed by the author et ...

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 ...

Spark-assisted homogeneous charge compression ignition (HCCI) combustion may be a method to improve the operation of HCCI engines. In the current study, the impact of spark assist on the fundamental properties of ignition and combustion was investigated in a single cylinder, optically-accessible research engine. Early port fuel injection and air preheating were used with indolene fuel in the st...

Homogeneous charge compression ignition (HCCI) engines are attracting attention as next-generation internal combustion engines mainly because of very low NOx and PM emission potential and excellent thermal efficiency. Particulate emissions from HCCI engines have been usually considered negligible however recent studies suggest that PM number emissions from HCCI engines cannot be neglected. This...

Homogeneous charge compression ignition (HCCI) is an advanced combustion concept that is developed as an alternative to diesel engines with higher thermal efficiency along with ultralow NOx and PM emissions. To study the performance of this novel technique, experiments were performed in a two cylinder engine, in which one cylinder is modified to operate in HCCI mode while other cylinder operate...

A mathematical engine model is developed in this paper to study the operation process in HCCI engines. Isooctane is used as fuel for testing in this model. Two-step reaction mechanisms are implemented to model combustion process and heat transfer process is also included. Results from this model show good correlation with experiment with respect to combustion phasing, pressure rise and peak pre...

An experimental study has been conducted to provide insight into heat transfer to the piston of a light-duty single-cylinder research engine under Conventional Diesel (CDC), Homogeneous Charge Compression Ignition (HCCI), and Reactivity Controlled Compression Ignition (RCCI) combustion regimes. Two fast-response surface thermocouples embedded in the piston top measured transient temperature. A ...