Gas turbine engine
A gas turbine engine includes a turbomachine having an engine core including a high-pressure compressor, a combustion section, a high-pressure turbine, and a high-pressure shaft coupled to the high-pressure compressor and the high-pressure turbine. The engine core has a length (L CORE ), and the high-pressure compressor has an exit stage diameter (D CORE ). The high-pressure compressor defines a high-pressure compressor exit area (A HPCExit ) in square inches. The gas turbine engine defines a redline exhaust gas temperature (EGT) in degrees Celsius, a total sea level static thrust output (Fn Total ) in pounds, and a corrected specific thrust, wherein the corrected specific thrust is greater than or equal to 42 and less than or equal to 90, the corrected specific determined as follows: Fn Total ×EGT/(A HPCExit 2 ×1000). The high-pressure shaft is characterized by a high-speed shaft rating (HSR) from 1.5 to 6.2, and a ratio of L CORE /D CORE is from 2.1 to 4.3.
1 . A gas turbine engine comprising:
a turbomachine comprising a compressor section having a high-pressure compressor, a combustion section, and a turbine section having a high-pressure turbine arranged in serial flow order, the turbomachine includes an engine core including the high-pressure compressor, the combustion section, and the high-pressure turbine, the engine core having a length (L CORE ) in inches, the high-pressure compressor having an exit stage diameter (D CORE ) in inches, the high-pressure compressor defining a high-pressure compressor exit area (A HPCExit ) in square inches, and the high-pressure compressor including a high-pressure compressor flowpath and a plurality of stages of high-pressure compressor rotor blades and high-pressure compressor stator vanes, wherein the gas turbine engine defines a redline exhaust gas temperature (EGT) in degrees Celsius, a total sea level static thrust output (Fn Total ) in pounds, and a corrected specific thrust, wherein the corrected specific thrust is greater than or equal to 42 and less than or equal to 90, the corrected specific thrust determined as follows: Fn Total ×EGT/(A HPCExit 2 ×1000); and
a high-pressure shaft coupled to the high-pressure compressor and the high-pressure turbine, the high-pressure shaft characterized by a high-pressure shaft rating (HSR LP ) from 0.8 to 1.6, and HSR LP is given by:
HSR
L
P
=
1
k
*
N
1
r
/
l
*
D
C
O
R
E
*
(
L
C
O
R
E
D
C
O
R
E
)
2
,
where N1 r/l is a redline speed of a low-pressure shaft in RPM, and k is a constant with a value of 10 6 inch-RPM.
2 . The gas turbine engine of claim 1 , wherein the high-pressure compressor includes eight stages, nine stages, ten stages, or eleven stages.
3 . The gas turbine engine of claim 1 , wherein the high-pressure compressor includes nine stages, ten stages, or eleven stages.
4 . The gas turbine engine of claim 1 , wherein the high-pressure turbine includes one stage or two stages.
5 . The gas turbine engine of claim 1 , further comprising:
a fan; and
a reduction gearbox, wherein the fan is driven by the turbomachine across the reduction gearbox.
6 . The gas turbine engine of claim 5 , wherein a gear ratio of the reduction gearbox is within a range of 6.0 to 14.0.
7 . The gas turbine engine of claim 6 , wherein the fan comprises a plurality of unducted rotor blades that are variable pitch rotor blades.
8 . The gas turbine engine of claim 5 , wherein a gear ratio of the reduction gearbox is within a range of 3.2 to 4.5.
9 . The gas turbine engine of claim 1 , further comprising:
an inlet duct downstream of the primary fan and upstream of the compressor section of the turbomachine; and
a secondary fan located within the inlet duct, wherein a ratio of a radius of the unducted fan to a radius of the secondary fan is at least 3.3 and less than or equal to 7.
10 . The gas turbine engine of claim 1 , wherein the redline exhaust gas temperature (EGT) is from 1,063° C. to 1,282° C.
11 . The gas turbine engine of claim 1 , wherein a ratio L CORE /D CORE is a function of a high-pressure shaft operating parameter (HSP X ) given by:
HSP
X
=
(
A
e
x
)
2
*
P
STD
*
OPR
T
/
O
FN
T
/
O
*
(
N
S
t
g
/
10
)
2
,
where N Stg is the number of stages in the high-pressure compressor, A EX equals A HPCExit , P STD is standard pressure in pounds per square inch, OPR T/O is an overall pressure ratio of the gas turbine engine at takeoff flight conditions corresponding to a maximum thrust rating for an engine core configuration, and FN T/O is a sea-level static thrust in lbf of the gas turbine engine at takeoff flight conditions corresponding to the maximum thrust rating for the engine core configuration.
12 . The gas turbine engine of claim 11 , wherein L CORE /D CORE is less than
4
.
0
8
(
HSP
X
-
8
)
0.14
.
13 . The gas turbine engine of claim 11 , wherein HSP X is from 3.8 in 2 to 69.1 in 2 .
14 . The gas turbine engine of claim 11 , wherein A EX is from 11 in 2 to 95 in 2 .
15 . The gas turbine engine of claim 11 , wherein P STD is approximately 14.7 psi.
16 . The gas turbine engine of claim 11 , wherein OPR T/O is from 26.3 to 82, and wherein FN T/O is from 12,674 lbf to 107,480 lbf.
17 . The gas turbine engine of claim 11 , wherein A EX is given by:
A
E
X
=
π
*
(
R
TIP
,
EX
2
-
R
HUB
,
E
X
2
)
,
where R TIP,EX is a radius in inches of a tip of a high-pressure compressor blade of the exit stage of the high-pressure compressor, and R HUB,EX is a radius in inches of a hub of the high-pressure compressor at the exit stage.
18 . The gas turbine engine of claim 17 , wherein R TIP,EX is from 4.73 in. to 15.83 in., and wherein R HUB,EX is from 4.31 in. to 14.85 in.
19 . A method of operating the gas turbine engine of claim 1 , the method comprising operating the gas turbine engine to generate an engine thrust, a redline speed of the high-pressure shaft (N2 r/l ) in RPM being from 10,580 RPM to 35,788 RPM.
20 . A gas turbine engine comprising:
a turbomachine comprising a compressor section having a high-pressure compressor, a combustion section, and a turbine section having a high-pressure turbine arranged in serial flow order, the turbomachine includes an engine core including the high-pressure compressor, the combustion section, and the high-pressure turbine, the engine core having a length (L CORE ) in inches, the high-pressure compressor having an exit stage diameter (D CORE ) in inches, the high-pressure compressor defining a high-pressure compressor exit area (A HPCExit ) in square inches, and the high-pressure compressor including a high-pressure compressor flowpath and a plurality of stages of high-pressure compressor rotor blades and high-pressure compressor stator vanes, wherein the gas turbine engine defines a redline exhaust gas temperature (EGT) in degrees Celsius, a total sea level static thrust output (Fn Total ) in pounds, and a corrected specific thrust, wherein the corrected specific thrust is greater than or equal to 42 and less than or equal to 90, the corrected specific thrust determined as follows: Fn Total ×EGT/(A HPCExit 2 ×1000);
a power turbine in flow communication with the high-pressure turbine;
a low-pressure shaft coupled to the power turbine; and
a high-pressure shaft coupled to the high-pressure compressor and the high-pressure turbine, the high-pressure shaft characterized by a high-pressure shaft rating (HSR LP ) from 0.8 to 1.6 and HSR LP is given by:
HSR
L
P
=
1
k
*
N
1
r
/
l
*
D
C
O
R
E
*
(
L
C
O
R
E
D
C
O
R
E
)
2
,
where N1 r/l is a redline speed of a low-pressure shaft in RPM and k is a constant with a value of 10 6 inch-RPM.