An internal combustion engine includes a combustion chamber, at least one intake port for directing intake air into the combustion chamber with no/low swirling; a piston with piston bowl, an injector with plurality of orifices arranged to inject fuel with high injection pressure to form spray plumes, each of the plurality of orifices having a central axis oriented at a positive spray angle sufficient to cause the spray/flame to impinge on a piston outer bowl section and a 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 vertical upwardly directed and tangential movements of the spray/flame and to preserve mixing energy late in the combustion cycle for increased soot oxidation.