Injector nozzle spray hole with Venturi and air entertainment feature

A method of conducting fuel injection in an engine, comprising:

• opening a fuel injecting apparatus in response to an operation signal from an engine control system;
• inserting fuel through a primary passage formed in the fuel injection apparatus, the primary passage comprising a first portion, a second portion, and a third portion, wherein the second portion is disposed between the first portion and the third portion and has a cross-sectional area smaller than that of both the first portion and the third portion;
• directing air into the primary passage through a secondary passage that is fluidly coupled with the second portion of the primary passage, wherein the primary passage defines a first central axis, and the secondary passage defines a second central axis, such that the first and second central axes are offset from and nonplanar with each other to cause a swirling motion of air injected into the second portion of the one or more primary passages;
• and
• combusting a mixture of air and fuel inside the engine.

An engine system comprising:

• a plurality of cylinder heads, each cylinder head defining a combustion chamber;
• a plurality of fuel injectors, each fuel injector coupled with one of the plurality of cylinder heads and comprising:
• an inner sac with one or more primary passages extending therefrom, the one or more primary passages configured to inject fuel into the combustion chamber and comprising a first portion, a second portion, and a third portion, wherein the second portion is disposed between the first portion and the third portion and has a cross-sectional area smaller than that of both the first portion and the third portion, and
• one or more secondary passages extending from the combustion chamber to fluidly couple with the second portion of the one or more primary passages, the one or more secondary passages configured to inject air from the combustion chamber to form fuel-and-air mixture with the fuel injected from the one or more primary passages, wherein each of the one or more primary passages defines a first central axis, and each of the one or more secondary passages defines a second central axis, such that the first and second central axes are offset from and nonplanar with each other to cause a swirling motion of air injected into the second portion of the one or more primary passages;
• and
• a plurality of pistons, each piston coupled to the combustion chamber of the one of the plurality of cylinder heads.