Estudo da variabilidade ciclo a ciclo em um motor HCCI

Abstract

The study of new technologies related to internal combustion engines has become increasingly necessary as regulations on emissions and demand for greater energy efficiency turn more stringent and challenging. Inevitably, hybrid and electric vehicle technologies are expected to dominate the market in the future; however, there is still a long way to go before these technologies become commercially prevalent. With the dominance of internal combustion engines for the next decades, a need arises for deepening studies and research seeking their improvement through the application of new technologies, such as the Homogeneous Charge Compression Ignition (HCCI) technology. This technology allows achieving thermal efficiencies comparable to those of conventional diesel engines, with the advantage of reduced pollutant emission. However, this technology also presents some barriers for its application, such as cycle-by-cycle variability. Thus, through the simulation of a single-cylinder engine fueled with pure ethanol and operated in HCCI mode, this work aims at identifying the operational conditions causing unstable combustion and the consequent cycle-by-cycle variability.