Ducted combustion systems utilizing duct structures

An internal combustion engine, comprising:

• an engine block having at least one cylinder bore;
• a cylinder head having a flame deck surface disposed at one end of the cylinder bore;
• a piston connected to a crankshaft and configured to reciprocate within the cylinder bore, the piston having a piston top surface facing the flame deck surface such that a combustion chamber is defined within the cylinder bore bound at a first end by the flame deck surface and at a second end by the piston top surface;
• a fuel injector in fluid connection with the combustion chamber and including a plurality of orifices in an injector tip of a fuel injector, the plurality of orifices injecting fuel into the combustion chamber as a plurality of fuel jets;
• and
• a duct structure defining a plurality of ducts and disposed within the combustion chamber between the flame deck surface and the piston top surface, the plurality of ducts being disposed such that each of the plurality of fuel jets at least partially enters one of the plurality of ducts upon being injected into the combustion chamber, wherein the duct structure is a generally conical disc structure.