TECHNICAL FIELD

The present disclosure relates generally to fuel systems of gas turbine engines and, more particularly, to fuel nozzle assemblies for such fuel systems.

BACKGROUND

Fuel nozzles of gas turbine engines operate by atomizing liquid fuel into a flow of droplets suitable for combustion and efficient extraction of energy. One or more conduits are provided for carrying the fuel from a fuel source of the engine toward atomizing features of the fuel nozzle. Typically, such conduits must be routed along non-linear paths and are segmented across multiple components between the fuel source and the fuel nozzle. Such discontinuities, particularly where gaps or unwanted fuel galleries may be formed, may lead to coking, a phenomenon by which a deposit of fuel constituents such as carbon may gradually build-up onto conduit walls when high-temperature yet unburned fuel runs therealong. Monitoring and servicing techniques dedicated to coking management are conventionally employed to maintain optimal fuel nozzle performance and minimize engine downtime.

SUMMARY

In an aspect of the present technology, there is provided a fuel nozzle assembly for a fuel system of a gas turbine engine, the fuel nozzle assembly comprising: a fuel nozzle at a downstream end of the fuel nozzle assembly relative to fuel flow through the fuel nozzle assembly; a first body and a second body upstream of the fuel nozzle, the first body defining a first fuel passage extending between a first inlet fluidly connectable to a fuel source of the fuel system and a first outlet, and the second body defining a second fuel passage extending between a second inlet and a second outlet in fluid communication with the nozzle, the first outlet and the second inlet being in fluid communication with each other; a downstream end of the first body having the first outlet and an upstream end of the second body having the second inlet matingly engaged together along an engagement axis, the first outlet and the second inlet being spaced apart in an axial direction relative to the engagement axis to define a gallery between the first body and the second body, the gallery having a depth in the axial direction and a width in a transverse direction relative to the engagement axis; and a gap filler disposed within the gallery, the gap filler being compressible in at least one of the axial direction and the transverse direction, the gap filler having an uncompressed dimension in said at least one of the axial direction and the transverse direction, the uncompressed dimension being greater than a corresponding dimension of the gallery in said at least one of the axial direction and the transverse direction.

In another aspect, there is provided a gas turbine engine, comprising: a compressor, a turbine and a combustor disposed between the compressor and the turbine, the combustor including a casing and a fuel nozzle assembly received inside the casing, the fuel nozzle assembly including: a fuel nozzle at a downstream end of the fuel nozzle assembly relative to fuel flow through the fuel nozzle assembly; a fuel nozzle adapter and a fuel nozzle stem upstream of the fuel nozzle, the adapter defining a first fuel passage extending between a first inlet in fluid communication with a fuel source of the gas turbine engine and a first outlet, and the stem defining a second fuel passage extending between a second inlet and a second outlet in fluid communication with the fuel nozzle, the first outlet and the second inlet being in fluid communication with each other; a downstream end of the adapter having the first outlet and an upstream end of the stem having the second inlet matingly engaged together along an engagement axis, the first outlet and the second inlet being spaced apart in an axial direction relative to the engagement axis to define a gallery between the adapter and the stem, the gallery having a depth in the axial direction; and a gap filler disposed within the gallery, the gap filler being compressible in the axial direction, the gap filler having an uncompressed axial length being greater than a corresponding dimension of the gallery in the axial direction.

In yet another aspect, there is also provided a method of making a fuel nozzle assembly including: aligning a downstream portion of a fuel nozzle adapter with an upstream portion of a nozzle stem relative to an engagement axis, matingly engaging the downstream portion and the upstream portion along the engagement axis such that the downstream portion and the upstream portion together define a gallery, positioning the downstream portion relative to the upstream portion relative to one another along the engagement axis so as to define an axial depth of the gallery and to position an outlet of the upstream portion and an inlet of the downstream portion at either end of a gap filler located inside the gallery and extending axially relative to the axial depth.

In some embodiments, the method further comprises compressing the gap filler between the upstream and downstream portions so as to conform the gap filler to the axial depth of the gallery.

In some embodiments, the method further comprises positioning the gap filler relative to at least one of the upstream and downstream portions so as to direct a passage of the gap filler away from the outlet of the upstream portion toward the inlet of the downstream portion.

In some embodiments, the method comprises affixing the gap filler to one of the upstream and downstream portions prior to mating engagement.

