Rotor blade having a flared tip

Abstract

A rotor blade includes an airfoil having a blade tip and a tip cavity formed at the blade tip. The blade tip defines a radially outer surface of the airfoil. The tip cavity includes a tip cap that is recessed radially inwardly from the tip and surrounded by pressure and suction side walls of the airfoil. The tip cap is in fluid communication with an internal cavity defined within the airfoil. A portion of at least one of the suction side wall or the pressure side wall that defines the tip cavity extends obliquely outwardly from the tip cavity. A plurality of slots is defined in at least one of the suction side wall or the pressure side wall along the radially outer surface proximate to the trailing edge of the airfoil.

What is claimed is: 
     
         1 . A rotor blade, comprising:
 an airfoil having a pressure side wall and a suction side wall connected at leading and trailing edges of the airfoil, a blade tip defining a radially outer surface of the airfoil, and an internal cavity for receiving a cooling medium; and   a tip cavity in fluid communication with the internal cavity and at least partially defined by a tip cap recessed radially inwardly from the radially outer surface and surrounded by the pressure and suction side walls, wherein a portion of at least one of the suction side wall or the pressure side wall that defines the tip cavity extends obliquely outwardly from the tip cavity, wherein a plurality of slots is defined in at least one of the suction side wall or the pressure side wall along the radially outer surface proximate to the trailing edge of the airfoil.   
     
     
         2 . The rotor blade as in  claim 1 , wherein at least one slot of the plurality of slots extends radially into a top surface of the tip cap. 
     
     
         3 . The rotor blade as in  claim 1 , wherein at least one slot of the plurality of slots includes at least one of a widened inlet defined along an inner surface of the pressure or suction side walls, a widened outlet defined along an outer surface of the pressure or suction side walls or a narrowing region defined between the inlet and outlet. 
     
     
         4 . The rotor blade as in  claim 1 , wherein the plurality of slots includes a first slot defined in the pressure side wall and a second slot defined within the suction side wall along the radially outer surface proximate to the trailing edge of the airfoil. 
     
     
         5 . The rotor blade as in  claim 1 , wherein a top surface of the tip cap is stepped radially inwardly proximate to the trailing edge. 
     
     
         6 . The rotor blade as in  claim 1 , further comprising a plurality of apertures that extend through the tip cap, wherein the plurality of apertures provide for fluid communication between the internal cavity and the tip cavity, wherein at least one aperture of the plurality of apertures is defined upstream from at least one slot of the plurality of slots. 
     
     
         7 . The rotor blade as in  claim 1 , wherein one or more slots of the plurality of slots is angled towards the trailing edge with respect to a chamber line of the airfoil. 
     
     
         8 . The rotor blade as in  claim 1 , further comprising a hole defined along the trailing edge of the airfoil and positioned radially below the tip cap, wherein the hole is in fluid communication with the internal cavity. 
     
     
         9 . The rotor blade as in  claim 1 , wherein a portion of the suction side wall that defines the tip cavity extends obliquely outwardly from the tip cavity with respect to a radial direction. 
     
     
         10 . The rotor blade as in  claim 1 , wherein a portion of the pressure side wall that defines the tip cavity extends obliquely outwardly from the tip cavity with respect to a radial direction. 
     
     
         11 . A gas turbine, comprising:
 a compressor section;   a combustion section; and   a turbine section, the turbine section having a rotor shaft and a plurality of rotor blades coupled to the rotor blade, each rotor blade comprising:   an airfoil having a pressure side wall and a suction side wall connected at leading and trailing edges of the airfoil, a blade tip defining a radially outer surface of the airfoil, and an internal cavity for receiving a cooling medium; and   a tip cavity in fluid communication with the internal cavity and at least partially defined by a tip cap recessed radially inwardly from the radially outer surface and surrounded by the pressure and suction side walls, wherein a portion of at least one of the suction side wall or the pressure side wall that defines the tip cavity extends obliquely outwardly from the tip cavity, wherein a plurality of slots is defined in at least one of the suction side wall or the pressure side wall along the radially outer surface proximate to the trailing edge of the airfoil.   
     
     
         12 . The gas turbine as in  claim 11 , wherein at least one slot of the plurality of slots extends into a top surface of the tip cap. 
     
     
         13 . The gas turbine as in  claim 11 , wherein at least one slot of the plurality of slots includes at least one of a widened inlet defined along an inner surface of the pressure or suction side walls, a widened outlet defined along an outer surface of the pressure or suction side walls or a narrowing region defined between the inlet and outlet. 
     
     
         14 . The gas turbine as in  claim 11 , wherein the plurality of slots includes a first slot defined in the pressure side wall and a second slot defined within the suction side wall along the radially outer surface proximate to the trailing edge of the airfoil. 
     
     
         15 . The gas turbine as in  claim 11 , wherein a top surface of the tip cap is stepped radially inwardly proximate to the trailing edge. 
     
     
         16 . The gas turbine as in  claim 11 , further comprising a plurality of apertures that extend through the tip cap, wherein the plurality of apertures provide for fluid communication between the internal cavity and the tip cavity, wherein at least one aperture of the plurality of apertures is defined along a chamber line of the airfoil between adjacent slots of the plurality of slots. 
     
     
         17 . The gas turbine as in  claim 11 , wherein one or more slots of the plurality of slots is angled towards the trailing edge with respect to a chamber line of the airfoil. 
     
     
         18 . The gas turbine as in  claim 11 , further comprising a hole defined along the trailing edge of the airfoil and positioned radially below the tip cap, wherein the hole is in fluid communication with the internal cavity. 
     
     
         19 . The gas turbine as in  claim 11 , wherein a portion of the suction side wall that defines the tip cavity extends obliquely outwardly from the tip cavity with respect to a radial direction. 
     
     
         20 . The gas turbine as in  claim 11 , wherein a portion of the pressure side wall that defines the tip cavity extends obliquely outwardly from the tip cavity with respect to a radial direction.