4-stroke active combustion (controlled auto-ignition) investigations using a single cylinder engine with lotus active valve train (AVT)

摘要

Lotus has devised two 4-stroke methods for initiating controlled auto-ignition (or Active Combustion). Both methods are found to improve feel consumption, thereby reducing carbon monoxide (CO) and carbon dioxide (CO{sub}2) emissions, reduce oxides of nitrogen (NO{sub}x) to ultra low levels and reduce hydrocarbons (HC's) significantly. The first method is sequential in mode and the second simultaneous in mode of trapping exhaust gases for combustion initiation. Combustion timing is found to be a function of the quantity of exhaust gas trapped in-cylinder. Increasing the quantity of trapped exhaust gas, advances the ignition toward top dead centre. A number of mechanisms (4) to elucidate the fendamental process of Active Combustion have been described relating the effects of pressure, temperature and chemical species in-cylinder as ignition is triggered.