The case for new divided-chamber diesel combustion systems - Part one: Critical analysis of current DI and past significant divided-chamber engines

摘要

This first of three papers discusses the Diesel Industry's potential survival vis-a-vis future environmental demands; and why Divided Chamber systems may be warranted. Ignitability and startability are linked to valve-timing more than to Nominal Compression Ratio (CR{sub}n) or chamber design. A proper Air-Cycle is key, as overlap and IVC affect the Effective Compression Ratio (CR{sub}e) and Trapped Air-Mass (TAM). An in-depth historical review reveals why some Divided-Chamber engines started and idled well, while others did not; and how much the operational characteristics were penalized by poor prechambers, injection systems and valve-timing events.