High area ratio turbine vane

Abstract

A vane for a turbine engine comprises an airfoil section, an inner platform and an outer platform. The airfoil section comprises pressure and suction surfaces extending from a leading edge to a trailing edge. The inner platform is attached to the airfoil section along an inner flow boundary, where the inner flow boundary extends from an upstream inlet region of the vane to a downstream outlet region of the vane. The outer platform is attached to the airfoil section along an outer flow boundary, where the outer flow boundary extends from the inlet region to the outlet region. An area ratio of the outlet region to the inlet region is greater than 2.4.

1 . A vane for a turbine engine, the vane comprising:
 an airfoil section comprising pressure and suction surfaces extending from a leading edge to a trailing edge;   an inner platform attached to the airfoil section along an inner flow boundary, the inner flow boundary extending from an upstream inlet region of the vane to a downstream outlet region of the vane; and   an outer platform attached to the airfoil section along a outer flow boundary, the outer flow boundary extending from the upstream inlet region to the downstream outlet region;   wherein an area ratio of the outlet region to the inlet region is greater than 2.4.   
     
     
         2 . The vane of  claim 1 , wherein the area ratio comprises a ratio of a cross-sectional area of the outlet region between the inner flow boundary and the outer flow boundary, to a cross-sectional area of the inlet region between the inner flow boundary and the outer flow boundary. 
     
     
         3 . The vane of  claim 2 , wherein the area ratio is between 2.4 and 2.6. 
     
     
         4 . The vane of  claim 2 , wherein the area ratio is between 2.5 and 2.9. 
     
     
         5 . The vane of  claim 1 , wherein an aspect ratio of the vane is less than 2.0. 
     
     
         6 . The vane of  claim 5 , wherein the aspect ratio is 1.5 or less. 
     
     
         7 . The vane of  claim 6 , wherein a radial spacing between the inner flow boundary and the outer flow boundary varies between the inlet region and the outlet region. 
     
     
         8 . A turbine comprising the vane of  claim 1 , wherein the vane defines a portion of a flow duct about a turbine axis. 
     
     
         9 . The turbine of  claim 8 , wherein the airfoil section defines a local flow angle of at least ten degrees with respect to the turbine axis. 
     
     
         10 . A turbine vane comprising:
 an airfoil section comprising a leading edge, a trailing edge, and pressure and suction surfaces defined therebetween;   an inner platform attached to the airfoil section, the inner platform defining an inner flow boundary between an inlet region of the turbine vane and an outlet region of the turbine vane; and   an outer platform attached to the airfoil section, the outer platform defining an outer flow boundary between the inlet region of the turbine vane and the outlet region of the turbine vane;   wherein a ratio of a cross sectional area of the outlet region to a cross sectional area of the inlet region is greater than 2.4.   
     
     
         11 . The turbine vane of  claim 10 , wherein the ratio is less than 2.9 
     
     
         12 . The turbine vane of  claim 11 , wherein the ratio is at least 2.5. 
     
     
         13 . The turbine vane of  claim 10 , wherein an aspect ratio of the airfoil section is 1.5 or less. 
     
     
         14 . A turbine engine comprising a plurality of turbine vanes as specified in  claim 10 , the plurality of turbine vanes defining an annular flow duct about a turbine axis. 
     
     
         15 . The turbine engine of  claim 14 , wherein the plurality of turbine vanes define a duct angle of at least ten degrees with respect to the turbine axis. 
     
     
         16 . A turbine engine comprising:
 a plurality of vanes arranged circumferentially about a turbine axis, each of the vanes comprising an airfoil, an inner flow boundary defined along an inner radius of the airfoil, and an outer flow boundary defined along an outer radius of the airfoil; and   an annular flow duct defined between the inner flow boundary and the outer flow boundary, the annular flow duct having an inlet region and an outlet region;   wherein a ratio of a cross sectional area of the outlet region to a cross sectional area of the inlet region is between 2.4 and 2.9.   
     
     
         17 . The turbine engine of  claim 16 , wherein each of the airfoils has an aspect ratio of 1.5 or less. 
     
     
         18 . The turbine engine of  claim 17 , wherein the annular flow duct has a duct angle of at least ten degrees with respect to the turbine axis. 
     
     
         19 . The turbine engine of  claim 18 , further comprising:
 a first turbine section upstream of the turbine section; and   a second turbine section downstream of the turbine section;   wherein the annular flow duct comprises a transition duct between the first turbine section and the second turbine section.   
     
     
         20 . A turbofan engine comprising the turbine engine of  claim 19  in flow series with a compressor and a propulsion fan.