Fuel injector having an external cross-flow nozzle for enhanced compressed natural gas jet spray
A compressed natural gas fuel injector including a housing, an inlet, an outlet, a seat, a closure member, and an attached nozzle. In a preferred embodiment, the inlet and outlet communicate a flow of gaseous fuel regulated by the closure member. The gaseous fuel passes through the seat, which is coupled to a rim surface of a retainer portion of the attached nozzle, and into a flow passage that further communicates the flow of gaseous fuel into one or more flow channels. The orientation of the flow channels within the attached nozzle greatly affects the discharge pattern and mixing characteristics of the gaseous fuel within an intake manifold. A method of flowing gaseous fuel through the fuel injector is also described.
1. A fuel injector comprising:
an inlet and an outlet and a passage extending along a longitudinal axis from the inlet to the outlet, the inlet communicable with a flow of gaseous fuel;
a closure member disposed in at least two positions along the longitudinal axis in the passage;
a seat disposed in the passage proximate the outlet, the seat including a sealing surface contiguous to a portion of the closure member in one of the two position of the closure member and a seat orifice extending through the seat from the sealing surface along the longitudinal axis;
a flow modifier having a retainer portion and flow modifier portion, the retainer portion being coupled to an outer surface of the outlet, the flow modifier including:
a first flow modifier surface and a second flow modifier surface, the first flow modifier surface disposed about the longitudinal axis to define a flow passage in fluid communication with the seat orifice and the second flow modifier surface disposed along and about a first axis generally orthogonal to the longitudinal axis to define at least a flow channel,
wherein the second flow modifier surface further comprises a second flow channel diametric to the first flow channel along the first axis, and third and fourth flow channels aligned along a second axis orthogonal to the first and longitudinal axes,
wherein each of the flow channels comprises a flow channel having a generally circular cross-section about respective first and second axes,
wherein the retainer portion comprises:
a first retainer surface contiguous to an outer surface of the outlet along the longitudinal axis to define a cylindrical inner retainer surface;
a second retainer surface that surrounds the outer surface of the outlet at an oblique angle along the longitudinal axis to define a truncated conic inner retainer surface; and
a third retainer surface defining a generally planar surface contiguous to the second retainer surface and the flow modifier portion to define an annular pocket about the longitudinal axis.
2. The fuel injector of claim 1 , wherein the first flow modifier surface comprises a tapered surface about the longitudinal axis to define a truncated conic surface contiguous to a cylindrical surface disposed about the longitudinal axis that form the flow passage.
3. The fuel injector of claim 2 , wherein the second flow modifier surface comprises a surface cincturing the first axis to define a cylindrical flow channel surface.
4. The fuel injector of claim 3 , wherein the outlet comprises a flange portion disposed in the annular pocket.
5. The fuel injector of claim 4 , wherein the outlet comprises a boss portion disposed about the longitudinal axis, the boss portion having a top surface to retain a sealing member and a bottom surface contiguous to a rim of the retainer portion.
6. The fuel injector of claim 5 , wherein the rim has an outer diameter of about 9 millimeters.
7. The fuel injector of claim 6 , wherein the cylindrical inner retainer surface comprises a cylinder with an inside diameter of about 8 millimeters and a length along the longitudinal axis of about 2 millimeters.
8. The fuel injector of claim 6 , wherein the flow modifier has an overall length of about 7 millimeters.
9. The fuel injector of claim 6 , wherein the cylindrical flow channel surface comprises a cylinder with an inside diameter of about 2 millimeters.