Abstract: A diesel cycle, direct injected internal combustion engine is provided with a piston recess or bowl into which fuel is injected each combustion cycle. One or more reaction chambers adjacent the piston recess are in communication with the recess through an array of discrete orifices located along the side wall of the recess. Partial reaction of fuel and air in the reaction chambers each combustion cycle produces radicals including intermediate species for seeding a fuel air mixture of a following combustion cycle through a delayed discharge of radicals from the reaction chamber into the piston recess. The discrete orifices are arranged in a specific array that ensures a desired chaotic flow in the reaction chambers and maximum interaction between radicals discharged from the reaction chamber and the soot cloud formed in the combustion chamber upon ignition of the fuel air mixture in the piston recess.

Abstract: A combustion chamber for a direct injected, reciprocating piston diesel cycle internal combustion engine in which fuel is injected into a piston recess and wherein the piston includes a reaction chamber adjacent the piston recess that communicates with the combustion chamber through a discrete orifice, wherein the orifice is located so as to discharge reaction products from the reaction chamber into the central portion of a soot cloud that is formed during combustion of fuel each combustion cycle.