US 11,781,447 B2
Low pressure ratio fan engine having a dimensional relationship between inlet and fan size
Wesley K. Lord, South Glastonbury, CT (US); Robert E. Malecki, Storrs, CT (US); Yuan J. Qiu, Glastonbury, CT (US); Becky E. Rose, Colchester, CT (US); and Jonathan Gilson, West Hartford, CT (US)
Assigned to RTX CORPORATION, Farmington, CT (US)
Filed by RAYTHEON TECHNOLOGIES CORPORATION, Farmington, CT (US)
Filed on Sep. 23, 2021, as Appl. No. 17/482,666.
Application 17/482,666 is a continuation of application No. 16/391,476, filed on Apr. 23, 2019, granted, now 11,286,811.
Application 16/391,476 is a continuation of application No. 15/887,136, filed on Feb. 2, 2018, granted, now 10,301,971, issued on May 28, 2019.
Application 15/887,136 is a continuation of application No. 13/721,095, filed on Dec. 20, 2012, granted, now 9,920,653, issued on Mar. 20, 2018.
Prior Publication US 2022/0010689 A1, Jan. 13, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. F01D 25/24 (2006.01); F02K 3/06 (2006.01); F01D 5/14 (2006.01); F02C 7/04 (2006.01); F01D 5/02 (2006.01); F01D 15/12 (2006.01); F01D 17/10 (2006.01)
CPC F01D 25/24 (2013.01) [F01D 5/02 (2013.01); F01D 5/141 (2013.01); F01D 15/12 (2013.01); F01D 17/105 (2013.01); F02C 7/04 (2013.01); F02K 3/06 (2013.01); F05D 2220/32 (2013.01); F05D 2250/00 (2013.01); F05D 2260/40311 (2013.01); F05D 2260/96 (2013.01); Y02T 50/60 (2013.01)] 30 Claims
OG exemplary drawing
 
1. A gas turbine engine assembly comprising:
a fan section including a fan and a fan case surrounding the fan to define a bypass duct, the fan including a plurality of fan blades having circumferentially outermost edges, a diameter of the fan having a dimension D extending between the circumferentially outermost edges of the fan blades, each fan blade having a leading edge, and a forward most portion on the leading edges of the fan blades in a first reference plane perpendicular to an engine central longitudinal axis, wherein a portion of the fan case is forward of the leading edges of the fan blades relative to the engine central longitudinal axis, and the fan has a pressure ratio of greater than 1.20 and less than 1.45 across the fan blade alone at a cruise design point;
a compressor section including a low pressure compressor and a high pressure compressor;
a geared architecture defining a gear reduction ratio of greater than 2.3;
a turbine section including a high pressure turbine and a low pressure turbine, the low pressure turbine driving the fan through the geared architecture;
a nacelle surrounding the fan and the fan case, the nacelle including an inlet portion forward of the fan relative to the engine central longitudinal axis, a forward edge on the inlet portion in a second reference plane, the second reference plane oriented at an oblique angle relative to the first reference plane and to the engine central longitudinal axis, and a length of the inlet portion having a dimension L measured in a direction parallel to the engine central longitudinal axis between a location of the leading edges of the fan blades and the leading edge on the inlet portion;
wherein the fan delivers a portion of air into the compressor section and a portion of air into the bypass duct, and a bypass ratio of greater than 10, the bypass ratio being a ratio of a volume of air passing to the bypass duct compared to a volume of air passing into the compressor section; and
wherein the dimension L is different at a plurality of locations on the inlet portion, the leading edge on the inlet portion is further from the first reference plane near the top of the engine assembly than it is near the bottom of the engine assembly, a dimensional relationship of L/D varies with respect to the plurality of locations, the plurality of locations include a value of L/D that is between 0.30 and 0.40, a greatest value of L corresponds to a value of the dimensional relationship of L/D that is at most 0.45, and a smallest value of L corresponds to a value of the dimensional relationship of L/D that is at least 0.20.
 
18. A gas turbine engine assembly comprising:
a fan section including a fan and a fan case surrounding the fan to define a bypass duct, the fan including a plurality of fan blades having circumferentially outermost edges, a diameter of the fan having a dimension D extending between the circumferentially outermost edges of the fan blades, each fan blade having a leading edge, and a forward most portion on the leading edges of the fan blades in a first reference plane perpendicular to an engine central longitudinal axis, wherein a portion of the fan case is forward of the leading edges of the fan blades relative to the engine central longitudinal axis, the axial location of the leading edges of the fan blades relative to the engine central longitudinal axis varies from hub to tip, and the fan has a pressure ratio of greater than 1.20 and less than 1.45 across the fan blade alone at a cruise design point;
a compressor section including a low pressure compressor and a high pressure compressor;
a geared architecture defining a gear reduction ratio of greater than 2.3;
a turbine section including a high pressure turbine and a low pressure turbine, the low pressure turbine driving the fan through the geared architecture;
a nacelle surrounding the fan and the fan case, the nacelle including an inlet portion forward of the fan relative to the engine central longitudinal axis, a forward edge on the inlet portion in a second reference plane, the second reference plane oriented at an oblique angle relative to the first reference plane and to the engine central longitudinal axis, and a length of the inlet portion having a dimension L measured in a direction parallel to the engine central longitudinal axis between a location of the leading edges of the fan blades and the leading edge on the inlet portion;
wherein the fan delivers a portion of air into the compressor section and a portion of air into the bypass duct, and a bypass ratio of greater than 10, the bypass ratio being a ratio of a volume of air passing to the bypass duct compared to a volume of air passing into the compressor section; and
wherein the dimension L is different at a plurality of locations on the inlet portion, the leading edge on the inlet portion is further from the first reference plane near the top of the engine assembly than it is near the bottom of the engine assembly, a dimensional relationship of L/D varies with respect to the plurality of locations, and the plurality of locations include a value of L/D that is between 0.30 and 0.40.