Fuel spray nozzle for a gas turbine engine
A fuel spray nozzle comprises a fuel passage ( 1 ) having at least one inlet and at least one outlet. The outlet is configured for accelerating fuel exiting the fuel passage into a jet. An air swirler ( 3 ) is arranged outboard of the fuel passage and converges to a single outlet chamber ( 5 ) adjacent the fuel passage outlet(s). The air swirler ( 3 ) can be nominally concentrically arranged but have some freedom to move axially or radially or change its angular position. The fuel passage outlets may be arranged symmetrically in an annular configuration. An air passage may be arranged axially within the annular array of fuel passage outlets.
1. A fuel spray nozzle comprising:
a fuel injector: and
an annular air swirler, wherein
the fuel injector comprises a fuel passage arranged centrally of the annular air swirler and having at least one fuel inlet and at least one fuel outlet, the at least one fuel outlet configured for accelerating fuel exiting the fuel passage into a jet of fuel, and
the annular air swirler comprises one or more swirl passages, the one or more swirl passages comprising at least one radially outer wall with an end of the at least one radially outer wall converging towards an axis of the annular swirler and the one or more swirl passages converging towards the axis to a single outlet, the at least one fuel outlet directed towards the radially outer wall at a position upstream of said end of said wall so that a center line of the fuel passage at the at least one fuel outlet forms a non-zero angle with a center line of the fuel injector at the at least one fuel outlet, wherein, in use, the jet of fuel is directed across a stream of air exiting the one or more swirl passages at the single outlet.
2. The fuel spray nozzle as claimed in claim 1 , wherein the annular air swirler is nominally concentrically arranged with respect to the fuel passage.
3. The fuel spray nozzle as claimed in claim 1 , wherein the at least one fuel outlet and walls of the one or more swirl passages, including the at least one wall, are directed towards each other so as to create a collision of the fuel and air streams which is within an angle range, the vertex of the angle being downstream from the at least one fuel outlet, the angle range selected such that, in use, the fuel penetrates as far as possible across a radially adjacent swirl passage, without impingement on an outer wall of the walls of a swirl passage of the one or more swirl passages, the swirl passage being radially distal to a fuel outlet of the at least one fuel outlet.
4. The fuel spray nozzle as claimed in claim 3 , wherein the angle range is 30 to 150 degrees.
5. The fuel spray nozzle as claimed in claim 4 , wherein the angle range is 60 to 150 degrees.
6. The fuel spray nozzle as claimed in claim 5 , wherein the angle range is 90 to 130 degrees.
7. The fuel spray nozzle as claimed in claim 1 , further comprising a seal component arranged between the air swirler and the fuel passage and wherein the seal component is configured to allow radial and/or axial and/or angular movement between the air swirler and the fuel passage.
8. The fuel spray nozzle as claimed in claim 7 , wherein the seal component is configured to permit a metered flow between the air swirler and the fuel injector.
9. The fuel spray nozzle as claimed in claim 1 comprising a plurality of fuel passage outlets, including the at least one fuel outlet, symmetrically arranged in an annular configuration.
10. The fuel spray nozzle as claimed in claim 1 , wherein upstream of the single outlet, the air swirler comprises the one or more swirl passages coaxially arranged and extending annularly, the one or more swirl passages including vanes configured to impart swirl on the stream of air.
11. The fuel spray nozzle as claimed in claim 1 , wherein the fuel passage is annular and further comprising an air jet co-axially arranged in an air passage passing axially through the annular fuel passage.
12. The fuel spray nozzle as claimed in claim 1 , wherein the air swirler outlet and/or the at least one fuel outlet have a profiled throat configured to control a cone angle of the stream of air.
13. The fuel spray nozzle as claimed in claim 1 , further including an annular void space around the fuel passage which serves as a heat shield for the fuel passage.
14. The fuel spray nozzle as claimed in claim 1 , including an axially downstream and radially outwardly extending heat shield formed integrally with the annular air swirler.
15. A gas turbine engine incorporating a fuel spray nozzle, the fuel spray nozzle having the configuration as set forth in claim 1 .
16. The fuel spray nozzle as claimed in claim 1 , wherein the end of each wall converging towards the axis of the annular air swirler at least partially define the single outlet where the at least one fuel outlet sits.
17. A fuel spray nozzle comprising:
a fuel injector; and
an annular air swirler, wherein
the fuel injector comprises a fuel passage arranged centrally of the annular air swirler and having at least one fuel inlet and at least one fuel outlet, the at least one fuel outlet configured for accelerating fuel exiting the fuel passage into a jet of fuel, and
the annular air swirler comprises one or more swirl passages, the one or more swirl passages comprising at least one radially outer wall with an end of the at least one radially outer wall converging towards an axis of the annular swirler and the one or more swirl passages converging towards the axis to a single outlet, the at least one fuel outlet directed towards the radially outer wall at a position upstream of said end of said wall, wherein, in use, the jet of fuel is directed across a stream of air exiting the one or more swirl passages at the single outlet; and
a seal component arranged between the air swirler and the fuel passage and wherein the seal component is configured to allow radial and/or axial and/or angular movement between the air swirler and the fuel passage.
18. A fuel spray nozzle comprising:
a fuel injector; and
an annular air swirler, wherein
the fuel injector comprises a fuel passage arranged centrally of the annular air swirler and having at least one fuel inlet and at least one fuel outlet, the at least one fuel outlet configured for accelerating fuel exiting the fuel passage into a jet of fuel,
the annular air swirler comprises one or more swirl passages, the one or more swirl passages comprising at least one radially outer wall with an end of the at least one radially outer wall converging towards an axis of the annular swirler and the one or more swirl passages converging towards the axis to a single outlet, the at least one fuel outlet directed towards the radially outer wall at a position upstream of said end of said wall, wherein, in use, the jet of fuel is directed across a stream of air exiting the one or more swirl passages at the single outlet, and
the fuel passage is annular and further comprising an air jet co-axially arranged in an air passage passing axially through the annular fuel passage.