Turbofan engine having angled inlet pre-swirl vanes

Abstract

A turbofan engine is provided. The turbofan engine includes a fan having a plurality of fan blades; a turbomachine operably coupled to the fan for driving the fan, the turbomachine having a compressor section, a combustion section, and a turbine section in serial flow order and together defining a core air flowpath; a nacelle surrounding and at least partially enclosing the fan, the nacelle defining a radius and a longitudinal axis; and an inlet pre-swirl vane located upstream of the plurality of fan blades and defining a chord, the inlet pre-swirl vane coupled to the nacelle, wherein the inlet pre-swirl vane is angled at a first angle with respect to the radius of the nacelle, and wherein the chord of the inlet pre-swirl vane is angled at a second angle with respect to the longitudinal axis of the nacelle.

1 . A turbofan engine comprising:
 a fan comprising a plurality of fan blades;   a turbomachine operably coupled to the fan for driving the fan, the turbomachine comprising a compressor section, a combustion section, and a turbine section in serial flow order and together defining a core air flowpath;   a nacelle surrounding and at least partially enclosing the fan, the nacelle defining a radius and a longitudinal axis; and   an inlet pre-swirl vane located upstream of the plurality of fan blades and defining a chord, the inlet pre-swirl vane coupled to the nacelle, wherein the inlet pre-swirl vane is angled at a first angle with respect to the radius of the nacelle, and wherein the chord of the inlet pre-swirl vane is angled at a second angle with respect to the longitudinal axis of the nacelle.   
     
     
         2 . The turbofan engine of  claim 1 , wherein the inlet pre-swirl vane is angled at the first angle with respect to the radius of the nacelle in a clockwise direction from an inlet of the nacelle. 
     
     
         3 . The turbofan engine of  claim 1 , wherein the inlet pre-swirl vane is angled at the first angle with respect to the radius of the nacelle in a counterclockwise direction from an inlet of the nacelle. 
     
     
         4 . The turbofan engine of  claim 1 , wherein the first angle is between approximately 2 degrees and approximately 45 degrees. 
     
     
         5 . The turbofan engine of  claim 1 , wherein the second angle is between approximately 5 degrees and approximately 35 degrees. 
     
     
         6 . The turbofan engine of  claim 1 , wherein the inlet pre-swirl vane is one of a plurality of part span inlet guide vanes extending from the nacelle upstream of the plurality of fan blades and aft of an inlet of the nacelle. 
     
     
         7 . The turbofan engine of  claim 6 , wherein each of the plurality of part span inlet guide vanes is angled at the same first angle with respect to the radius of the nacelle. 
     
     
         8 . The turbofan engine of  claim 6 , wherein a first portion of each of the plurality of part span inlet guide vanes is angled at the first angle with respect to the radius of the nacelle,
 wherein a second portion of each of the plurality of part span inlet guide vanes is angled at a third angle with respect to the radius of the nacelle, and   wherein the first angle is different than the third angle.   
     
     
         9 . The turbofan engine of  claim 6 , wherein the nacelle includes a top portion, a bottom portion, a first side portion, and a second side portion,
 wherein a first portion of each of the plurality of part span inlet guide vanes is angled at the first angle with respect to the radius of the nacelle at the top portion,   wherein a second portion of each of the plurality of part span inlet guide vanes is angled at a third angle with respect to the radius of the nacelle at the bottom portion, and   wherein the first angle is different than the third angle.   
     
     
         10 . A nacelle assembly for a turbofan engine, the turbofan engine comprising a fan including a plurality of fan blades, the nacelle assembly comprising:
 a nacelle surrounding and at least partially enclosing the fan, the nacelle defining a radius and a longitudinal axis; and   an inlet pre-swirl vane located upstream of the plurality of fan blades and defining a chord, the inlet pre-swirl vane coupled to the nacelle,   wherein the inlet pre-swirl vane is angled at a first angle with respect to the radius of the nacelle, and   wherein the chord of the inlet pre-swirl vane is angled at a second angle with respect to the longitudinal axis of the nacelle.   
     
     
         11 . The nacelle assembly of  claim 10 , wherein the inlet pre-swirl vane is angled at the first angle with respect to the radius of the nacelle in a clockwise direction from an inlet of the nacelle. 
     
     
         12 . The nacelle assembly of  claim 10 , wherein the inlet pre-swirl vane is angled at the first angle with respect to the radius of the nacelle in a counterclockwise direction from an inlet of the nacelle. 
     
     
         13 . The nacelle assembly of  claim 10 , wherein the first angle is between approximately 2 degrees and approximately 45 degrees. 
     
     
         14 . The nacelle assembly of  claim 10 , wherein the second angle is between approximately 5 degrees and approximately 35 degrees. 
     
     
         15 . The nacelle assembly of  claim 10 , wherein the inlet pre-swirl vane is one of a plurality of part span inlet guide vanes extending from the nacelle upstream of the plurality of fan blades and aft of an inlet of the nacelle. 
     
     
         16 . The nacelle assembly of  claim 15 , wherein each of the plurality of part span inlet guide vanes is angled at the same first angle with respect to the radius of the nacelle. 
     
     
         17 . The nacelle assembly of  claim 15 , wherein a first portion of each of the plurality of part span inlet guide vanes is angled at the first angle with respect to the radius of the nacelle,
 wherein a second portion of each of the plurality of part span inlet guide vanes is angled at a third angle with respect to the radius of the nacelle, and   wherein the first angle is different than the third angle.   
     
     
         18 . The nacelle assembly of  claim 15 , wherein the nacelle includes a top portion, a bottom portion, a first side portion, and a second side portion,
 wherein a first portion of each of the plurality of part span inlet guide vanes is angled at the first angle with respect to the radius of the nacelle at the top portion,   wherein a second portion of each of the plurality of part span inlet guide vanes is angled at a third angle with respect to the radius of the nacelle at the bottom portion, and   wherein the first angle is different than the third angle.   
     
     
         19 . (canceled) 
     
     
         20 . (canceled) 
     
     
         21 . The turbofan engine of  claim 1 , wherein the inlet pre-swirl vane includes an outer end and an inner end, wherein the inner end is radially inward from the outer end, and wherein the second angle of the chord at the outer end is greater than the second angle of the chord at the inner end. 
     
     
         22 . The turbofan engine of  claim 1 , wherein the inlet pre-swirl vane includes an outer end and an inner end, wherein the inner end is radially inward from the outer end, and wherein the second angle of the chord increases from the inner end to the outer end.