Method and system for late cycle oxygen injection in an internal combustion engine

A method of reducing particulate emissions from a compression ignition engine, said engine having an intake manifold and at least one piston assembly moveable within a cylinder to form a combustion chamber, an intake air system adapted for providing intake air to said intake manifold and combustion chamber, and an exhaust system adapted for transporting exhaust gases from said combustion chamber, said method comprising the steps of:

• moving said piston assembly in said cylinder to increase the volume of said combustion chamber and inducting a charge of intake air from said intake manifold into said combustion chamber;
• moving said piston assembly in said cylinder to compress said charge of intake air in said combustion chamber;
• introducing fuel into said combustion chamber and igniting said mixture of fuel and charge of compressed intake air to form expanding exhaust gas within said combustion chamber;
• introducing a charge of supplemental oxygen enriched air into said combustion chamber late in a combustion cycle after ignition of said mixture of fuel and charge of compressed intake air, wherein said charge of supplemental oxygen enriched air reacts with said exhaust gases resident within in said combustion chamber to form exhaust gases having reduced particulate content;
• and
• moving said piston assembly within said cylinder to expel said exhaust gases having reduced particulate content from said combustion chamber to said exhaust system.

An air flow management system for an internal combustion engine, said engine having an intake manifold and at least one combustion chamber, an intake air system adapted for providing intake air to said intake manifold and combustion chamber, and an exhaust system adapted for transporting exhaust gases from said combustion chamber, said air flow management system comprising:

• an oxygen enriched air source;
• an oxygen enriched air flow circuit extending from said oxygen enriched air source to said combustion chamber while circumventing said intake manifold;
• a flow control device disposed along said oxygen enriched air flow circuit, said flow control device adapted for introducing said oxygen enriched air from said oxygen enriched air circuit into said combustion chamber;
• and
• a controller operatively coupled to said flow control device and adapted to control the introduction of said oxygen enriched air into said combustion chamber late in said combustion cycle in response to selected engine operating conditions.