Thermal Barriers Adoption in D.I. Diesel Engines: Effect on Smoke and Gaseous Emissions

The paper describes some experiments carried out on two DI Diesel engines running with insulated pistons. Three different thermal barriers were tested; namely, a stainless steel cup, a Si3N4 cup and a stainless steel piston crown. The combustion process was characterized by heat release calculation and ignition delay measurements. The experiments showed that the indicated efficiency is not affected by thermal insulation adoption, NOx level increases while smoke level decreases consistently.