Lean combustion is one of the most applied methods to increase engine efficiency and maintain a good trade-off with engine emissions. The pre-chamber combustion (PCC) is one of the most promising combustion concepts to extend the lean operating limits of the engine. The Narrow throat pre-chamber has shown long lean limit extension than other ignition sources. The pre-chamber combustion and main-chamber combustion were studied in a Heavy-Duty optical engine using methane fuel to determine the generalities of the combustion process in the two volumes: pre- and main chamber. The combustion process was recorded using three collection systems: (a) Natural Flame Luminosity (NFL), (b) OH* Chemiluminescence, and (c) CH* Chemiluminescence. Additionally, the effect of three pre-chamber geometrical parameters, volume, nozzle area and throat diameter, on the pre-chamber combustion was also addressed in this research. The generalities of the pre-chamber combustion inside the pre-chamber exhibited a flame propagation nature for the combustion process, with high propagation velocities inside the throat. The main chamber process for the reference narrow throat pre-chamber exhibited defined jets from six of the twelve jets corresponding to the bottom row of nozzles for the reference pre-chamber. Regarding the geometrical parameters, the throat area to nozzle area ratio determines the propagation mode for the main chamber, evolving from only six jets and ultra-low throat intensity for ultra-low ratios to, twelves jethe ts with same penetration and high throat intensity for ratios above one.
|Date of Award
- Physical Sciences and Engineering
|James Turner (Supervisor)