Nozzle film cooling with alternating compound angles

Abstract

A nozzle segment for a nozzle ring of a gas turbine engine is disclosed. The nozzle segment includes a first endwall, a second endwall, and an airfoil extending between the first endwall and the second endwall. The airfoil includes a multiple groups of cooling apertures spaced apart and alternating in directionality such that a first grouping of cooling apertures is angled toward the first endwall, a second grouping of cooling apertures is angled toward the second endwall and spaced apart from the first grouping of cooling apertures, and a third grouping of cooling apertures are angled toward the first endwall and spaced apart from the second grouping of cooling apertures.

What is claimed is: 
     
         1 . A nozzle segment for a nozzle ring of a gas turbine engine, the nozzle segment comprising:
 a first endwall;   a second endwall; and   an airfoil extending between the first endwall and the second endwall, the airfoil including
 a leading edge extending radially from the first endwall to the second endwall, 
 a trailing edge extending radially from the first endwall to the second endwall axially distal to the leading edge, 
 a pressure side wall extending from the leading edge to the trailing edge, 
 a suction side wall extending from the leading edge to the trailing edge, 
 a plurality of showerhead cooling apertures spanning along the leading edge, 
 a plurality of forward cooling apertures grouped together in the pressure side wall proximate the plurality of showerhead cooling apertures, and 
 a plurality of intermediate cooling apertures grouped together in the pressure side wall between the trailing edge and the plurality of forward cooling apertures, 
 the plurality of showerhead cooling apertures, the plurality of forward cooling apertures, and the plurality of intermediate cooling apertures alternating in directionality such that the plurality of showerhead cooling apertures are angled toward the first endwall, the plurality of forward cooling apertures are angled toward the second endwall, and the plurality of intermediate cooling apertures are angled toward the first endwall. 
   
     
     
         2 . The nozzle segment of  claim 1 , wherein each showerhead cooling aperture is angled toward the first endwall as each showerhead cooling aperture extends through a wall of the airfoil, each forward cooling aperture includes a forward compound angle from fifteen to forty-five degrees towards the second endwall relative to a flow direction of air through the nozzle segment during operation, and each intermediate cooling aperture including an intermediate compound angle from fifteen to forty-five degrees towards the first endwall relative to a flow direction of air through the nozzle segment during operation. 
     
     
         3 . The nozzle segment of  claim 2 , wherein the airfoil further includes a plurality of aft cooling apertures grouped together in the pressure side wall proximate the trailing edge, each aft cooling aperture including an aft compound angle from fifteen to forty-five degrees towards the second endwall relative to a flow direction of air through the nozzle segment during operation. 
     
     
         4 . The nozzle segment of  claim 1 , wherein the plurality of forward cooling apertures are arranged in a single column and the plurality of intermediate cooling apertures are arranged in a single column. 
     
     
         5 . The nozzle segment of  claim 1 , wherein the first endwall is a lower endwall and the second endwall is an upper endwall located radially outward from the lower endwall. 
     
     
         6 . The nozzle segment of  claim 1 , wherein each forward cooling aperture is spaced apart from an adjacent forward cooling aperture from 3 to 4 pitch over diameter and each intermediate cooling aperture is spaced apart from an adjacent intermediate cooling aperture from 3 to 4 pitch over diameter. 
     
     
         7 . The nozzle segment of  claim 1 , wherein the plurality of showerhead cooling apertures is configured to direct air to film cool the leading edge and cool the first endwall, the plurality of forward cooling apertures is configured to direct air to film cool a pressure side surface of the pressure side wall and cool the second endwall, and the plurality of intermediate cooling apertures is configured to direct air to film cool the pressure side surface and cool the first endwall. 
     
     
         8 . A gas turbine engine including the nozzle segment of  claim 1 , wherein the nozzle segment is located in a first stage turbine nozzle of the gas turbine engine. 
     
     
         9 . A nozzle segment for a nozzle ring of a gas turbine engine, the nozzle segment comprising:
 a first endwall;   a second endwall;   an airfoil extending between the first endwall and the second endwall, the airfoil including
 a leading edge extending radially from the first endwall to the second endwall, 
 a trailing edge extending radially from the first endwall to the second endwall, 
 a pressure side wall extending from the leading edge to the trailing edge, the pressure side wall including a pressure side surface with a concave shape, the pressure side surface being the outer surface of the pressure side wall, 
 a suction side wall extending from the leading edge to the trailing edge, 
 a cooling cavity located between the leading edge, the trailing edge, the pressure side wall, and the suction side wall, 
 a plurality of showerhead cooling apertures spanning along the leading edge, each showerhead cooling aperture including a showerhead inlet end adjacent the cooling cavity and a showerhead outlet end at the outer surface of the leading edge, the showerhead inlet end being radially closer to the second endwall than the showerhead outlet end and the showerhead outlet end being radially closer to the first endwall than the showerhead inlet end, 
 a plurality of forward cooling apertures in the pressure side wall grouped together and spaced apart from the plurality of showerhead cooling apertures at least ⅛ the length of the pressure side wall, each forward cooling aperture including a forward inlet end adjacent the cooling cavity and a forward outlet end adjacent the pressure side surface, the forward inlet end being radially closer to the first endwall and axially closer to the leading edge than the forward outlet end, and the forward outlet end being radially closer to the second endwall and axially closer to the trailing edge than the forward inlet end, and 
 a plurality of intermediate cooling apertures in the pressure side wall grouped together and spaced apart from the plurality of forward cooling apertures at least ⅛ the length of the pressure side wall, each intermediate cooling aperture including an intermediate inlet end adjacent the cooling cavity and an intermediate outlet end adjacent the pressure side surface, the intermediate inlet end being radially closer to the second endwall and axially closer to the leading edge than the intermediate outlet end, and the intermediate outlet end being radially closer to the first endwall and axially closer to the trailing edge than the intermediate inlet end. 
   
     
     
         10 . The nozzle segment of  claim 9 , wherein the airfoil further includes a plurality of aft cooling apertures in the pressure side wall grouped together and spaced apart from the plurality of intermediate cooling apertures at least ⅛ the length of the pressure side wall, each aft cooling aperture including an aft inlet end adjacent the cooling cavity and an aft outlet end adjacent the pressure side surface, the aft inlet end being radially closer to the first endwall and axially closer to the leading edge than the aft outlet end, and the aft outlet end being radially closer to the second endwall and axially closer to the trailing edge than the aft inlet end. 
     
     
         11 . The nozzle segment of  claim 9 , wherein the first endwall is a lower endwall of a lower shroud and the second endwall is an upper endwall of an upper shroud, the lower endwall being located radially inward from the upper endwall. 
     
     
         12 . The nozzle segment of  claim 9 , wherein each forward cooling aperture is spaced apart from an adjacent forward cooling aperture from 3 to 4 pitch over diameter and each intermediate cooling aperture is spaced apart from an adjacent intermediate cooling aperture from 3 to 4 pitch over diameter. 
     
     
         13 . The nozzle segment of  claim 10 , wherein each forward cooling aperture is spaced apart from an adjacent forward cooling aperture from 3 to 4 pitch over diameter, each intermediate cooling aperture is spaced apart from an adjacent intermediate cooling aperture from 3 to 4 pitch over diameter, and each aft cooling aperture is spaced apart from an adjacent aft cooling aperture from 3 to 4 pitch over diameter. 
     
     
         14 . A nozzle segment for a nozzle ring of a gas turbine engine, the nozzle segment comprising:
 an upper shroud including an upper endwall, the upper endwall being the shape of a sector of a toroid;   a lower shroud including a lower endwall located radially inward from the upper endwall, the lower endwall being the shape of a sector of a toroid;   an airfoil extending between the upper endwall and the lower endwall, the airfoil including
 a leading edge extending radially from the upper endwall to the lower endwall, 
 a trailing edge extending radially from the upper endwall to the lower endwall axially distal to the leading edge, 
 a pressure side wall extending from the leading edge to the trailing edge, the pressure side wall including a concave shape, 
 a suction side wall extending from the leading edge to the trailing edge, the suction side wall including a convex shape, 
 a cooling cavity located between the leading edge, the trailing edge, the pressure side wall, and the suction side wall, 
 a plurality of showerhead cooling apertures arranged in four to seven columns spanning along the leading edge, each showerhead cooling aperture being angled toward the lower endwall as each showerhead cooling aperture extends through a wall of the airfoil from the cooling cavity, 
 a plurality of forward cooling apertures arranged in a column extending radially between the upper endwall and the lower endwall and located in the third of the pressure side wall adjacent the leading edge, each forward cooling aperture extending through the pressure side wall from the cooling cavity and including a forward compound angle from fifteen to forty-five degrees towards the upper endwall and the trailing edge relative to a reference line in the plane of a pressure side surface of the pressure side wall, the reference line being defined as an intersection between the pressure side surface and a plane perpendicular to a radial extending from an axis of the upper shroud along the pressure side surface, 
 a plurality of intermediate cooling apertures arranged in a column extending radially between the upper endwall and the lower endwall and located in the middle third of the pressure side wall between the leading edge and the trailing edge, each intermediate cooling aperture extending through the pressure side wall from the cooling cavity and including an intermediate compound angle from fifteen to forty-five degrees towards the lower endwall and the trailing edge relative to the reference line, and 
 a plurality of aft cooling apertures arranged in a column extending radially between the upper endwall and the lower endwall and located in the third of the pressure side wall adjacent the trailing edge, each aft cooling aperture extending through the pressure side wall from the cooling cavity and including an aft compound angle from fifteen to forty-five degrees towards the upper endwall and the trailing edge relative to the reference line. 
   
     
     
         15 . The nozzle segment of  claim 14 , further comprising:
 a second airfoil extending between the upper endwall and the lower endwall, the second airfoil including
 a second leading edge extending radially from the upper endwall to the lower endwall, 
 a second trailing edge extending radially from the upper endwall to the lower endwall distal to the second leading edge, 
 a second pressure side wall extending from the second leading edge to the second trailing edge, the second pressure side wall including a second concave shape, 
 a second suction side wall extending from the second leading edge to the second trailing edge, the second suction side wall including a second convex shape, 
 a second cooling cavity located between the second leading edge, the second trailing edge, the second pressure side wall, and the second suction side wall, 
 a plurality of second showerhead cooling apertures arranged in four to seven columns spanning along the second leading edge, each second showerhead cooling aperture being angled toward the lower endwall as each second showerhead cooling aperture extends through a second wall of the second airfoil from one of the second cooling cavity, 
 a plurality of second forward cooling apertures arranged in a column extending radially between the upper endwall and the lower endwall and located in the third of the second pressure side wall adjacent the second leading edge, each second forward cooling aperture extending through the second pressure side wall from the second cooling cavity and including a second forward compound angle from fifteen to forty-five degrees towards the upper endwall and the second trailing edge relative to a second reference line in the plane of a second pressure side surface of the second pressure side wall, the second reference line being defined as an intersection between the second pressure side surface and a second plane perpendicular to a radial extending from the axis of the upper shroud along the second pressure side surface, 
 a plurality of second intermediate cooling apertures arranged in a column extending radially between the upper endwall and the lower endwall and located in the middle third of the second pressure side wall between the second leading edge and the second trailing edge, each second intermediate cooling aperture extending through the second pressure side wall from the second cooling cavity and including a second intermediate compound angle from fifteen to forty-five degrees towards the lower endwall and the second trailing edge relative to the second reference line, and 
 a plurality of second aft cooling apertures arranged in a column extending radially between the upper endwall and the lower endwall and located in the third of the second pressure side wall adjacent the second trailing edge, each second aft cooling aperture extending through the second pressure side wall from the second cooling cavity and including a second aft compound angle from fifteen to forty-five degrees towards the upper endwall and the second trailing edge relative to the second reference line. 
   
     
     
         16 . The nozzle segment of  claim 14 , wherein each forward cooling aperture is spaced apart from an adjacent forward cooling aperture from 3 to 4 pitch over diameter, each intermediate cooling aperture is spaced apart from an adjacent intermediate cooling aperture from 3 to 4 pitch over diameter, and each aft cooling aperture is spaced apart from an adjacent aft cooling aperture from 3 to 4 pitch over diameter. 
     
     
         17 . The nozzle segment of  claim 14 , wherein each forward cooling aperture is spaced apart from an adjacent forward cooling aperture at 3.5 pitch over diameter, each intermediate cooling aperture is spaced apart from an adjacent intermediate cooling aperture at 3.5 pitch over diameter, and each aft cooling aperture is spaced apart from an adjacent aft cooling aperture at 3.5 pitch over diameter. 
     
     
         18 . The nozzle segment of  claim 14 , wherein the plurality of forward cooling apertures are spaced apart from the plurality of showerhead cooling apertures from ⅛ to ¼ the length of the pressure side wall, the plurality of intermediate cooling apertures are spaced apart from the plurality of forward cooling apertures from ¼ to ⅜ the length of the pressure side wall, and the plurality of aft cooling apertures are spaced apart from the plurality of intermediate cooling apertures from ¼ to ⅜ of the length of the pressure side wall. 
     
     
         19 . The nozzle segment of  claim 14 , wherein the forward compound angle is within a predetermined tolerance of thirty degrees, the intermediate compound angle is within a predetermined tolerance of thirty degrees, and the aft compound angle is within a predetermined tolerance of thirty degrees. 
     
     
         20 . A gas turbine engine including the nozzle segment of  claim 14 , wherein the nozzle segment is located in a first stage turbine nozzle of the gas turbine engine.