Nozzle

1. A fuel injector apparatus comprising:

a plurality of rings of nozzles, the rings being coaxial with an injector axis, each nozzle defining a gas flow path having an outlet for discharging a fuel/air mixture jet; and means for introducing said fuel to said air, wherein one or more groups of the nozzles are oriented to direct the associated jets along axes non-coplanar, non-intersecting, and non-parallel to the injector axis.

2. The apparatus of claim 1 wherein:

a first group of the one or more groups includes every nozzle of at least a first of said rings.

3. The apparatus of claim 1 wherein:

a first group of the one or more groups includes every nozzle of at least an outermost of said rings.

4. The apparatus of claim 1 wherein:

a first group of the one or more groups includes every nozzle of at least a first and a second of said rings, said nozzles of said first and second rings being oriented to direct their associated jets with an angular component of like sign about the injector axis.

5. The apparatus of claim 1 wherein the one or more groups include a first, a second, and a third of the rings.

6. The apparatus of claim 1 wherein the means provides at least partially independent control of fuel delivery to a first group of the one or more groups relative to others of the nozzles.

7. The apparatus of claim 1 used with a gas turbine engine combustor.

8. A method for engineering a fuel injector apparatus, the apparatus comprising: a plurality of rings of nozzles, the rings being coaxial with an injector axis, each nozzle defining a gas flow path having an outlet for discharging a fuel/air mixture jet; and means for introducing said fuel to said air, wherein one or more groups of the nozzles are oriented to direct the associated jets along axes non-coplanar, non-intersecting, and non-parallel to the injector axis.

the method comprising iteratively: selecting one or more off-longitudinal orientations for respective groups of the one or more groups; and determining at least one performance factor associated with the selected one or more off-longitudinal orientations, so as to achieve a selected performance.

9. The method of claim 8 wherein the determining comprises at least one of:

software simulation; and

physical measurement.

10. The method of claim 8 wherein the determining comprises:

determining said performance factor in view of or in combination with fuel/air ratios of the one or more groups at one or more operating conditions.

11. The method of claim 10 wherein the selecting is performed so as to achieve a target stabilization of one or more cool zones by one or more hot zones.

12. The method of claim 8 wherein the at least one performance factor includes levels of UHC, CO, and NOX at one or more power levels.

13. A fuel injector apparatus comprising:

a plurality of nozzles, each defining a gas flow path having:

an inlet receiving air;

a port receiving fuel; and

an outlet discharging a fuel/air mixture jet; and wherein one or more groups of the nozzles are oriented to direct the associated jets partially tangentially to a circumference coaxial with an overall flowpath from the injector.

14. The apparatus of claim 13 wherein:

the nozzles are arrayed in a plurality of concentric groups.

15. The apparatus of claim 13 wherein:

the nozzles are arrayed in a plurality of circularly-arrayed concentric groups.

16. The apparatus of claim 13 wherein:

the nozzles are formed in a common injector body.

17. The apparatus of claim 13 wherein:

the nozzles of a first of said groups are operated at a first fuel/air ratio;

the nozzles of a second of said groups, substantially outboard of the first group are fueled at a second fuel/air ratio, greater than the first fuel/air ratio; and

the nozzles of a third of said groups, substantially outboard of the second group are fueled at a third fuel/air ratio, less than the second fuel/air ratio.

18. The apparatus of claim 13 operating to provide:

a first combustion zone;

a second combustion zone inboard of the first and leaner than the first; and

a third combustion zone inboard of the second and richer than the second.

19. The apparatus of claim 18 wherein the first, second, and third combustion zones are below stoichiometric.

20. The apparatus of claim 1 further comprising:

a central nozzle along the injector axis.

21. A can-type combustor comprising:

a can-type wall structure having an inlet and an outlet and an interior; and

the apparatus of claim 1 positioned to introduced a fuel air mixture to the interior.