Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Experimental study in an optically accessible spark ignition engine using methane ignition with a lateral spark plug under stoichiometric and lean combustion
Submission Author:
Enrico Rapetti Malheiro de Oliveira , SP , Brazil
Co-Authors:
Enrico Rapetti Malheiro de Oliveira, Fábio Dias, Alexander Penaranda, Leila Ribeiro dos Santos, Andre Martelli, Pedro Lacava
Presenter: Enrico Rapetti Malheiro de Oliveira
doi://10.26678/ABCM.COBEM2023.COB2023-0779
Abstract
Commonly, in-cylinder pressure and exhaust gas analyses are used to investigate spark-ignition engines, but they lack details about the combustion process. To gain deeper insights into combustion itself, several authors have increasingly used optical techniques. In this study, it was employed optical methods to investigate combustion flame propagation in a unique setup where the spark plug is positioned laterally, which promotes ignition and flame propagation near the cylinder wall. This approach leads to greater heat exchange with the wall than with the center of the combustion chamber, where further investigation is needed to compare these results with engine cyclic variability, flame stability, and wrinkling. Experiments were conducted using methane (CH4) as fuel under stoichiometric and lean conditions at a fixed engine speed of 1000 rpm. The fuel mass flow rate was varied to adjust the air-fuel ratio (λ) to 1.5. The results revealed non-uniform flame propagation speeds, flame front stretching, and wrinkling due to the lateral spark plug positioning, resulting in engine instabilities and cyclic variability. Also, increasing air dilution resulted in less stable and efficient combustion. Leaner mixtures showed slower flame development and lower NO emissions.
Keywords
Experiments in optical access engine, flame images processing, Lateral ignition, Methane gas, lean combustion
