Search Results

Suppression or reduction of soot emissions is an important goal in the development of automotive engines for environmental and human health purposes. A better understanding at the molecular level of the formation process of soot particles resulting from collision and aggregation of smaller particles made of Polycyclic Aromatic Hydrocarbon (PAH) is needed. In addition to experiments, computational methods are efficient and valuable tools for this purpose. As a first step in our detailed computational chemistry study, we applied Ultra-Accelerated Molecular Dynamics (UAQCMD) and Canonical Monte-Carlo (CMC) methods to investigate the nucleation process. The UA-QCMD can calculate chemical reaction dynamics 107 times faster than conventional first principle molecular dynamics methods, while CMC can calculate equilibrium properties at various temperatures, pressures, and chemical compositions.

For recent high efficiency engine with high compression ratio and highly boosted technology, combustion occurs at resultant more elevated pressure condition, as compared to conventional engine, which is known to decrease laminar burning velocity and cause flame instability. Flame instability could play an important role in combustion performance, and so far many theoretical and experimental studies have been devoted to the relevant matters. In this study, effects of flame instabilities on the combustion properties, such as the topography of flame surface and the variation in flame speed, have been experimentally examined using a dual constant volume combustion chamber in consideration of elevated pressure combustion in state-of-art IC engine.