Iso-octane ignition delay times (τign) and hydroxyl (OH) radical mole fraction (χOH) time histories were measured under conditions relevant to homogeneous charge compression ignition engine operating regimes using the University of Michigan rapid compression facility. Absolute quantitative OH mole fraction time histories were obtained using differential narrow-line laser absorption of the R1(5)...

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...

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 ...

High-repetition-rate laser-induced fluorescence measurements of fuel and OH concentrations in internal combustion engines are demonstrated. Series of as many as eight fluorescence images, with a temporal resolution ranging from 10 micros to 1 ms, are acquired within one engine cycle. A multiple-laser system in combination with a multiple-CCD camera is used for cycle-resolved imaging in spark-ig...

Ignition and propagation of a reaction front in a counterflow system of an iso-octane/air stream mixing with an exhaust gas stream is computationally investigated to understand the fundamental characteristics of homogeneous charge compression ignition (HCCI) auto-ignition. Various mixing rates are imposed on the system and the effects of dissipation rates on auto-ignition are studied. Ignition ...

  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...

Use of liquefied petroleum gas (LPG) in compression-ignition (C-I) engines has always been considered important in the diesel engineering field. This is due to its easy accessibility and good combustion characteristics. In this paper the application of LPG fuel along with diesel oil in a direct- injection automotive diesel engine is experimentally investigated. In order to convert the pure dies...

PCCI engines can reduce NOx and PM emissions simultaneously without sacrificing thermal efficiency, but a low combustion temperature resulting from early fuel injection, and ignition occurring prior to TDC, can cause higher THC and CO emissions and fuel consumption. In conclusion, it was found that the PCCI combustion achieved by the 2-stage injection strategy with optimized calibration factors...

In wake of the present energy environment crises it has become essential to identify renewable and alternative clean burning fuels. One of the significant routes to tackle the problem of increasing prices and the pollution problems of petroleum fuels is by the use of vegetable oil fuels known as biodiesels. In the present work biodiesel was prepared from Honge oil (Pongamia) and used as a fuel ...