Gas turbine engine having composite fan blades
A gas turbine engine includes: a turbomachine comprising a drive turbine and defining a working gas flowpath and an inlet to the working gas flowpath; a fan having a fan blade formed of a composite material, the fan blade defining a leading edge fan radius R Fan_LE and a trailing edge fan radius R Fan_TE , and the fan defining a leading edge hub radius R Hub_LE and a trailing edge hub radius R Hub_TE , the gas turbine engine defining a bypass ratio during operation of the gas turbine engine in a cruise operating mode; and a reduction gearbox mechanically coupling the drive turbine of the turbomachine to the fan; wherein the gas turbine engine defines a Fan Leading Edge to Trailing Edge Compression Factor (FLTCF) greater than or equal to 1.05 and less than or equal to 1.8.
1 . A gas turbine engine defining a radial direction, the gas turbine engine comprising:
a turbomachine comprising a drive turbine and defining a working gas flowpath and an inlet to the working gas flowpath;
a fan having a fan blade formed of a composite material, the fan blade defining a leading edge fan radius R Fan_LE and a trailing edge fan radius R Fan_TE , and the fan defining a leading edge hub radius R Hub_LE and a trailing edge hub radius R Hub_TE , the gas turbine engine defining a bypass ratio equal to a mass flowrate of an airflow from the fan over the turbomachine to a mass flowrate of an airflow from the fan through the inlet to the working gas flowpath during operation of the gas turbine engine in a cruise operating mode, the bypass ratio being greater than or equal to 10 and less than or equal to 100; and
a reduction gearbox mechanically coupling the drive turbine of the turbomachine to the fan;
wherein the gas turbine engine defines a Fan Leading Edge to Trailing Edge Compression Factor (FLTCF) greater than or equal to 1.05 and less than or equal to 1.8, the FLTCF being equal to:
R
Fan
LE
×
R
Hub
TE
R
Fan
TE
×
R
Hub
LE
.
2 . The gas turbine engine of claim 1 , wherein the FLTCF is greater than or equal to 1.07 and less than or equal to 1.65.
3 . The gas turbine engine of claim 1 , wherein the bypass ratio is greater than or equal to 13 and less than or equal to 25.
4 . The gas turbine engine of claim 1 , wherein the turbomachine comprises a compressor section having a low pressure compressor and a high pressure compressor, wherein the low pressure compressor is rotatable with the drive turbine.
5 . The gas turbine engine of claim 1 , further comprising:
an outer nacelle surrounding at least in part the fan.
6 . The gas turbine engine of claim 1 , wherein the fan is an unducted fan.
7 . The gas turbine engine of claim 6 , wherein the leading edge fan radius R Fan_LE is greater than or equal to 65 inches and less than or equal to 85 inches, and wherein the fan defines a fan blade count greater than or equal to 5 and less than or equal to 15.
8 . The gas turbine engine of claim 6 , wherein the FLTCF is greater than or equal to 1.07 and less than or equal to 1.25.
9 . The gas turbine engine of claim 1 , wherein the leading edge fan radius R Fan_LE is greater than or equal to 35 inches and less than or equal to 50 inches, wherein the fan defines a fan blade count greater than or equal to 12 and less than or equal to 23, and wherein the reduction gearbox defines a gear ratio between 2:1 and 4:1.
10 . The gas turbine engine of claim 9 , wherein the FLTCF is greater than or equal to 1.12 and less than or equal to 1.35.
11 . The gas turbine engine of claim 1 , wherein the gas turbine engine defines a Fan Leading Edge to Trailing Edge Opening Ratio (FLTOR) greater than or equal to 1.03 and less than or equal to 1.5, the FLTOR being equal to:
R
Fan
LE
-
R
Hub
LE
R
Fan
TE
-
R
Hub
TE
.
12 . A gas turbine engine defining a radial direction, the gas turbine engine comprising:
a turbomachine comprising a drive turbine and defining a working gas flowpath and an inlet to the working gas flowpath;
a fan having a fan blade formed of a composite material, the fan blade defining a leading edge fan radius R Fan_LE and a trailing edge fan radius R Fan_TE , and the fan defining a leading edge hub radius R Hub_LE and a trailing edge hub radius R Hub_TE , the gas turbine engine defining a bypass ratio equal to a mass flowrate of an airflow from the fan over the turbomachine to a mass flowrate of an airflow from the fan through the inlet to the working gas flowpath during operation of the gas turbine engine in a cruise operating mode, the bypass ratio being greater than or equal to 10 and less than or equal to 100; and
a reduction gearbox mechanically coupling the drive turbine of the turbomachine to the fan;
wherein the gas turbine engine defines a Fan Leading Edge to Trailing Edge Opening Ratio (FLTOR) greater than or equal to 1.03 and less than or equal to 1.5, the FLTOR being equal to:
R
Fan
LE
-
R
Hub
LE
R
Fan
TE
-
R
Hub
TE
.
13 . The gas turbine engine of claim 12 , wherein the FLTOR is greater than or equal to 1.05 and less than or equal to 1.3.
14 . The gas turbine engine of claim 12 , wherein the bypass ratio is greater than or equal to 13 and less than or equal to 25.
15 . The gas turbine engine of claim 12 , further comprising:
an outer nacelle surrounding at least in part the fan.
16 . The gas turbine engine of claim 12 , wherein the fan is an unducted fan.
17 . The gas turbine engine of claim 16 , wherein the leading edge fan radius R Fan_LE is greater than or equal to 65 inches and less than or equal to 85 inches, wherein the fan defines a fan blade count greater than or equal to 5 and less than or equal to 15, and wherein the FLTOR is greater than or equal to 1.05 and less than or equal to 1.2.
18 . The gas turbine engine of claim 12 , wherein the leading edge fan radius R Fan_LE is greater than or equal to 35 inches and less than or equal to 50 inches, wherein the fan defines a fan blade count greater than or equal to 12 and less than or equal to 23, wherein the reduction gearbox defines a gear ratio between 2:1 and 4:1, and wherein the FLTOR is greater than or equal to 1.07 and less than or equal to 1.18.
19 . The gas turbine engine of claim 12 , wherein the gas turbine engine defines a Fan Leading Edge to Trailing Edge Compression Factor (FLTCF) greater than or equal to 1.05 and less than or equal to 1.8, the FLTCF being equal to:
R
Fan
LE
×
R
Hub
TE
R
Fan
TE
×
R
Hub
LE
.
20 . The gas turbine engine of claim 19 , wherein the fan is an unducted fan, wherein the leading edge fan radius R Fan_LE is greater than or equal to 65 inches and less than or equal to 85 inches, wherein the fan defines a fan blade count greater than or equal to 5 and less than or equal to 15, wherein the reduction gearbox defines a gear ratio greater than 4 and less than 12, wherein a thrust rating for the gas turbine engine is between 20,000 pounds and 45,000 pounds, wherein the FLTCF is greater than or equal to 1.07 and less than or equal to 1.25, and wherein the FLTOR is greater than or equal to 1.03 and less than or equal to 1.12.
21 . The gas turbine engine of claim 19 , wherein the fan is a ducted fan, wherein the leading edge fan radius R Fan_LE is greater than or equal to 35 inches and less than or equal to 50 inches, wherein the fan defines a fan blade count greater than or equal to 12 and less than or equal to 23, wherein the reduction gearbox defines a gear ratio greater than 2 and less than 4, wherein a thrust rating for the gas turbine engine is between 20,000 pounds and 45,000 pounds, wherein the FLTCF is greater than or equal to 1.12 and less than or equal to 1.35, and wherein the FLTOR is greater than or equal to 1.06 and less than or equal to 1.19.
22 . The gas turbine engine of claim 19 , wherein the fan is a ducted fan, wherein the leading edge fan radius R Fan_LE is greater than or equal to 51 inches and less than or equal to 66 inches, wherein the fan defines a fan blade count greater than or equal to 17 and less than or equal to 23, wherein a thrust rating for the gas turbine engine is between 60,000 pounds and 118,000 pounds, wherein the FLTCF is greater than or equal to 1.27 and less than or equal to 1.5, and wherein the FLTOR is greater than or equal to 1.18 and less than or equal to 1.5.
23 . The gas turbine engine of claim 19 , wherein the fan is a ducted fan, wherein the leading edge fan radius R Fan_LE is greater than or equal to 55 inches and less than or equal to 70 inches, wherein the fan defines a fan blade count greater than or equal to 12 and less than or equal to 22, wherein a thrust rating for the gas turbine engine is between 100,000 pounds and 150,000 pounds, wherein the FLTCF is greater than or equal to 1.46 and less than or equal to 1.65, and wherein the FLTOR is greater than or equal to 1.2 and less than or equal to 1.5.