US Patent 9506439 Ducted combustion systems utilizing adjustable length ducts

A ducted combustion system is disclosed. The ducted combustion system includes a combustion chamber bound by a flame deck surface of a cylinder head of an internal combustion engine and by a piston top surface of a piston disposed within the internal combustion engine. The system includes a fuel injector including one or more orifices, the one or more orifices injecting fuel into the combustion chamber as one or more fuel jets. The system includes one or more adjustable length ducts disposed within the combustion chamber between the flame deck surface and the piston top surface, the one or more adjustable length ducts being disposed such that each of the one or more fuel jets, at least partially, enters one of the one or more adjustable length ducts upon being injected into the combustion chamber.