Internal combustion engine and piston having stepped combustion bowl with non-axisymmetric profile

An internal combustion engine system comprising:

• an engine housing having a combustion cylinder formed therein;
• a fuel injector supported in the engine housing and having a plurality of spray orifices formed therein each defining a spray jet path;
• and
• a piston within the combustion cylinder and including a piston crown defining a piston center axis extending between a first piston axial end, and a second piston axial end having a combustion face;
• the combustion face forming a combustion bowl having a center cone and a bowl peripheral edge, a circumferential rim having a rim inner peripheral edge and a rim outer peripheral edge, and a step having a first step surface transitioning with the bowl peripheral edge and a second step surface transitioning with the rim inner peripheral edge;
• the combustion face having a profile of rotation around the piston center axis that is varied to form jet-jet interaction limiters;
• the jet-jet interaction limiters being arranged at locations offset from the spray jet paths and each including a bowl component protruding, within the combustion bowl to limit interaction between adjacent spray jets of combusting fuel injected from the plurality of spray orifices advanced radially outward through the combustion bowl, and a step component protruding, within the step, to limit interaction between the adjacent spray jets of combusting fuel once advanced from the combustion bowl into the step and spread azimuthally;
• and
• the combustion face profile includes a limiter profile at locations of the jet-jet interaction limiters, and a base profile at locations circumferentially between the jet-jet interaction limiters, and the limiter profile is congruous with the base profile.

A piston crown for a piston in an internal combustion engine comprising:

• a piston crown body including a piston outer surface having a top land and extending circumferentially around a piston center axis, a cooling gallery surface formed on a first axial side of the piston crown body, and a combustion face formed on a second axial side of the piston crown body;
• the combustion face forming a combustion bowl having a center cone and a bowl peripheral edge, a circumferential rim extending radially outward to the piston outer surface and having a rim outer peripheral edge and a rim inner peripheral edge, and a step having a first step surface transitioning with the bowl peripheral edge and a second step surface transitioning with the rim inner peripheral edge;
• the combustion face having a profile of rotation around the piston center axis that is varied to form jet-jet interaction limiters at spaced angular orientations around the piston center axis;
• and
• the jet-jet interaction limiters each including a bowl component protruding, within the combustion bowl, and a step component protruding, within the step, to limit interaction between adjacent spray jets of combusting fuel within the combustion bowl and the step;
• and
• the first step surface is formed in part upon the bowl component of each of the jet-jet interaction limiters, and the circumferential rim is formed in part upon the step component of each of the jet-jet interaction limiters.