Pre-chamber charge stratification of a spark ignited internal combustion engine
Thesis DisciplineMechanical Engineering
Degree GrantorUniversity of Canterbury
Degree NameMaster of Engineering
This thesis details and reviews the development of a Pre-Chamber Stratified Charge Combustion System developed on a Ricardo E6/Mk6 single cylinder, variable compression, spark ignition research engine in the Thermodynamics Laboratory of the Mechanical Engineering Department at the University of Canterbury. Operating a spark ignition engine on an overall lean charge has tile potential to simultaneously reduce exhaust emissions and maintain good thermal efficiency. However, problems associated with ignition of the lean mixture to increased exhaust emissions and reduced thermal efficiency. Stratified charge engines offer the potential to overcome these ignition problems, and restore thermal efficiency and reduce exhaust emissions. The stratified charge combustion process developed was centred around the separate injection of methane and air into a pre-chamber, located in an auxiliary spark plug hole in the cylinder head, to form an easily ignitable mixture which would establish a flame which would propagate through a lean mixture located in the main combustion chamber. Timing and duration of the injected methane was controlled electronically, whereas the air introduced into the pre-chamber was controlled by a metering valve and a check valve connected to the pre-chamber. The main charge to the engine was formed by using a gas carburettor.