Patent ID: 7918206

Claim:
An internal combustion engine with a combustion chamber, comprising: an engine body including an engine cylinder, a cylinder head forming an inner surface of the combustion chamber and at least one intake port formed in the cylinder head for directing intake air into the combustion chamber with no or low swirling effect during operation; a piston positioned for reciprocal movement in the engine cylinder between a bottom dead center position and a top dead center position, the piston including a piston crown comprising an upper surface facing the combustion chamber, the piston crown containing a piston bowl formed by an outwardly opening cavity, the piston bowl comprising a projecting portion having a distal end and an inner bowl floor section extending downwardly at an positive inner bowl floor angle from a plane perpendicular to an axis of reciprocation of the piston, the piston bowl further comprising an outwardly flared outer bowl section having a concave curvilinear shape in cross section; an injector mounted on the engine body adjacent the projecting portion of the piston bowl to inject fuel into the combustion chamber with high injection pressure, the injector comprising a plurality of orifices arranged to form fuel spray plumes, which eventually becomes flames, wherein each of the plurality of orifices has a central axis oriented at a positive spray angle from a plane perpendicular to the axis of reciprocation of the piston sufficient to cause the spray/flame to impinge on the outer bowl section and the curvilinear shape of the outer bowl section is such that a reflection angle of the impingement of the central axis is positive during at least start of injection in order to increase balance between tangential and vertical upwardly directed movements of the spray/flame and to preserve mixing energy late in the combustion cycle for increased soot oxidation.