Introducing steam into core air upstream of turbine engine diffuser plenum

1 . An aircraft propulsion system, comprising:

a propulsor rotor;

a turbine engine core configured to power the propulsor rotor, the turbine engine core comprising:

a core flowpath,

a compressor section,

a combustor section and

a turbine section,

the core flowpath extending through the compressor section, the combustor section and the turbine section from a flowpath inlet to a flowpath exhaust,

the compressor section comprising:

a low pressure compressor section and a high pressure compressor section,

 the low pressure compressor section comprising: a low pressure compressor rotor and

 the high pressure compressor section comprising; a high pressure compressor rotor,

the combustor section comprising:

 an injector assembly,

 a diffuser plenum and a combustor disposed within the diffuser plenum, the injector assembly comprising: a fuel injector and a swirler mated with the fuel injector, the fuel injector configured to inject fuel into a combustion chamber of the combustor, and the swirler configured to direct air received from the diffuser plenum into the combustion chamber of the combustor to facilitate mixing of the air with the fuel; and a steam system configured to introduce steam from an evaporator into the core flowpath downstream of the compressor section and upstream of the diffuser plenum between the high pressure compressor section and the diffuser plenum, at an inlet into the diffuser plenum,

wherein the turbine engine core further includes a pre-diffuser structure comprising; an inner wall and an outer wall, the core flowpath extends through the pre-diffuser structure to the diffuser plenum: wherein

at least one of the inner wall or the outer wall comprises a first section and a second section extending mainly axially, and an intermediate section extending mainly radially from an interior end connected to the first section to an exterior end connected to the second section, and wherein

the steam system comprises a first steam outlet on the intermediate section, and the steam system is configured to introduce the steam into the core flowpath through the first steam outlet.

2 . The aircraft propulsion system of claim 1 , wherein

the pre-diffuser structure includes a plurality of vanes arranged circumferentially about a centerline, each of the plurality of vanes extends across the core flowpath, and the plurality of vanes comprise a first vane; and

the steam system comprises a first second steam outlet configured with the first vane, and the steam system is configured to introduce the steam into the core flowpath through the first second steam outlet.

3 . The aircraft propulsion system of claim 2 , wherein

the first vane extends longitudinally between a leading end and a trailing end, and the first vane extends laterally between a first side and a second side; and

the first-second steam outlet is arranged at the trailing end.

4 . The aircraft propulsion system of claim 3 , wherein the steam system further comprises a third steam outlet arranged at the trailing end, and the steam system is configured to further introduce the steam into the core flowpath through the third steam outlet.

5 . The aircraft propulsion system of claim 3 , wherein the steam system further comprises a third steam outlet arranged along the first side, and the steam system is configured to further introduce the steam into the core flowpath through the third steam outlet.

6 . The aircraft propulsion system of claim 5 , wherein the steam system further comprises a fourth steam outlet arranged along the second side, and the steam system is configured to further introduce the steam into the core flowpath through the fourth steam outlet.

7 . The aircraft propulsion system of claim 2 , wherein

the first vane extends longitudinally between a leading end and a trailing end, and the first vane extends laterally between a first side and a second side; and

the second steam outlet is arranged at the first side.

8 . The aircraft propulsion system of claim 7 , wherein the steam system further comprises a third steam outlet arranged at the first side, and the steam system is configured to further introduce the steam into the core flowpath through the second third steam outlet.

9 . The aircraft propulsion system of claim 7 , wherein the steam system further comprises a third steam outlet arranged at the second side, and the steam system is configured to further introduce the steam into the core flowpath through the third steam outlet.

10 . The aircraft propulsion system of claim 2 , wherein

each of the plurality of vanes extends radially between and is connected to the inner wall and the outer wall; and

the inner wall forms an inner peripheral boundary of the core flowpath through the pre- diffuser structure, the outer wall forms an outer peripheral boundary of the core flowpath through the pre-diffuser structure, and the core flowpath radially expands as the core flowpath extends within the pre-diffuser structure towards the diffuser plenum.

11 . The aircraft propulsion system of claim 2 , wherein

the steam system further comprises a steam passage extending within the first vane; and

the second steam outlet extends through a sidewall of the first vane from the steam passage to the core flowpath.

12 . The aircraft propulsion system of claim 11 , wherein a supplementary passage extends within the first vane; and the supplementary passage is fluidly decoupled from the steam passage.

13 . The aircraft propulsion system of claim 12 , wherein the supplementary passage comprises a lubricant passage or an air passage.

14 . The aircraft propulsion system of claim 2 , wherein the intermediate section is downstream of the first vane.

15 . The aircraft propulsion system of claim 1 , wherein the combustor comprises a hollow, dual-walled structure comprising:

a combustor wall shell;

a combustor wall heat shield; and

one or more combustor wall cooling cavities radially formed between the combustor wall shell and the combustor wall heat shield.

16 . The aircraft propulsion system of claim 15 , wherein

the one or more combustor wall cooling cavities comprises a first cooling cavity;

the combustor wall shell comprises one or more impingement apertures;

the combustor wall heat shield comprises one or more effusion apertures;

the first cooling cavity is fluidly coupled to the diffuser plenum through the one or more impingement apertures; and

the first cooling cavity is fluidly coupled to the combustion chamber through the one or more effusion apertures.

17 . An assembly for a turbine engine, comprising:

a turbine engine core comprising:

a core flowpath,

a compressor section,

a combustor section, and

a turbine section, the core flowpath extending through the compressor section, the combustor section and the turbine section from a flowpath inlet to a flowpath exhaust,

the combustor section comprising:

a diffuser plenum and

a combustor disposed within the diffuser plenum, and

the compressor section includingcomprising:

a low pressure compressor section comprising:

 a low pressure compressor rotor, and a high pressure compressor section comprising: a high pressure compressor rotor,

a vane array structure comprising:

an inner wall,

an outer wall, the core flowpath extending through the vane array structure towards the diffuser plenum, at least one of the inner wall or the outer wall comprising; a first section and a second section extending mainly axially, and an intermediate section extending mainly radially from an interior end connected to the first section to an exterior end connected to the second section, and

a plurality of vanes arranged circumferentially about a centerline, each vane of the plurality of vanes extending across the core flowpath, the plurality of vanes comprising:

a first vane, the first vane extending longitudinally between a leading end and a trailing end, and the first vane extending laterally between a first side and a second side; and

a steam system comprising:

a steam source having an evaporator,

a first steam outlet on the intermediate section, and

a second steam outlet arranged along the first side of the first vane, the steam system

configured to inject steam from the evaporator into the core flowpath downstream of the

compressor section, upstream of the diffuser plenum between the high pressure

compressor section and the diffuser plenum, at an inlet into the diffuser plenum, and

through the first steam outlet and the second steam outlet.

18 . The assembly of claim 17 , wherein the steam system further comprises a third steam outlet arranged along the second side of the first vane, and the steam system is configured to further inject the steam into the core flowpath through the third steam outlet.

19 . An assembly for a turbine engine, comprising:

a turbine engine core including:

a compressor section,

a combustor section,

a turbine section and

a core flowpath,

the combustor section including:

a fuel injector,

a diffuser plenum, and

a combustor disposed within the diffuser plenum, and

the compressor section including:

a low pressure compressor section comprising:

 a low pressure compressor rotor, and

 a high pressure compressor section comprising:

 a high pressure compressor rotor, the fuel injector configured to inject fuel into a combustion chamber of the combustor, and the core flowpath extending through the compressor section, the combustor section and the turbine section from a flowpath inlet to a flowpath exhaust;

a peripheral boundary of the core flowpath upstream of the diffuser plenum formed by a flowpath wall, the flowpath wall extending circumferentially about and axially along a centerline, the flowpath wall comprising:

a first section,

a second section, and

an intermediate section extending mainly radially from an interior end connected to the first section to an exterior end connected to the second section, the first section extending mainly axially to the intermediate section, and the second section extending mainly axially from the intermediate section; and

a steam system comprising:

an evaporator, and

a plurality of steam outlets on the intermediate section, the steam system configured to inject steam from the evaporator into the core flowpath downstream of the compressor section and upstream of the diffuser plenum and the fuel injector, between the high pressure compressor section and the diffuser plenum, at an inlet into the diffuser plenum, and through the plurality of steam outlets.