Rotor blade with one or more side wall cooling circuits

Abstract

A rotor blade for a gas turbine engine includes an airfoil and a cooling microcircuit. The airfoil includes a first side wall, a second side wall and a tip endwall, where the first side wall and the second side wall extend to and cooperate to form the tip endwall, defining a main cavity between the first side wall and the second side wall. The cooling microcircuit includes a microcircuit cavity, an inlet, a side wall outlet and a tip outlet. The microcircuit cavity is embedded within the first side wall, and the inlet extends from the main cavity to the microcircuit cavity. The side wall outlet extends from the microcircuit cavity to an exterior first side surface of the airfoil. The tip outlet extends from the microcircuit cavity to an exterior tip surface of the airfoil.

What is claimed is: 
     
         1 . A rotor blade for a gas turbine engine, comprising:
 an airfoil comprising a first side wall, a second side wall and a tip endwall, wherein the first side wall and the second side wall extend to and cooperate to form the tip endwall defining a main cavity between the first side wall and the second side wall; and   a cooling microcircuit comprising
 a microcircuit cavity embedded within the first side wall; 
 an inlet extending from the main cavity to the microcircuit cavity; 
 a side wall outlet extending from the microcircuit cavity to an exterior first side surface of the airfoil; and 
 a tip outlet extending from the microcircuit cavity to an exterior tip surface of the airfoil. 
   
     
     
         2 . The rotor blade of  claim 1 , wherein the first side wall comprises a pressure side wall, and the second side wall comprises a suction side wall. 
     
     
         3 . The rotor blade of  claim 1 , wherein the first side wall comprises a suction side wall, and the second side wall comprises a pressure side wall. 
     
     
         4 . The rotor blade of  claim 1 , further comprising a tip shelf recessed into the tip endwall, wherein the tip shelf comprises the tip surface. 
     
     
         5 . The rotor blade of  claim 4 , wherein the tip surface is continuous with the first side surface. 
     
     
         6 . The rotor blade of  claim 1 , wherein at least a portion of the tip outlet extends to the tip surface along an axis that is angled relative to the first side surface. 
     
     
         7 . The rotor blade of  claim 1 , wherein the microcircuit cavity comprises a cavity length that extends radially through the first side wall, the inlet is one of a plurality of inlets that extend from the main cavity to the microcircuit cavity, and the inlets are arranged radially along the cavity length. 
     
     
         8 . The rotor blade of  claim 1 , wherein the microcircuit cavity comprises a cavity length that extends radially through the first side wall, the side wall outlet is one of a plurality of side wall outlets that extend from the microcircuit cavity to the first side surface, and the side wall outlets are arranged radially along the cavity length. 
     
     
         9 . The rotor blade of  claim 1 , further comprising a second microcircuit comprising
 a second microcircuit cavity embedded within the first side wall;   a second inlet extending from the main cavity to the second microcircuit cavity;   a second side wall outlet extending from the second microcircuit cavity to the first side surface; and   a second tip outlet extending from the second microcircuit cavity to the tip surface.   
     
     
         10 . The rotor blade of  claim 1 , further comprising a cooling passage extending from the main cavity to one of the first side surface and the tip surface. 
     
     
         11 . The rotor blade of  claim 1 , further comprising a protrusion extending into the microcircuit cavity. 
     
     
         12 . A turbine blade for a gas turbine engine, comprising:
 a hollow airfoil comprising a first side wall, a second side wall and a tip endwall, wherein the first side wall and the second side wall extend to the tip endwall forming a main cavity between the first side wall and the second side wall; and   a plurality of cooling microcircuits, each comprising
 a microcircuit cavity configured within the first side wall; 
 an inlet that directs cooling fluid from the main cavity into the microcircuit cavity; 
 a side wall outlet that directs a portion of the cooling fluid in the microcircuit cavity out of the airfoil to film cool an exterior first side surface of the airfoil; and 
 a tip outlet that directs a portion of the cooling fluid in the microcircuit cavity out of the airfoil to film cool an exterior tip surface of the airfoil. 
   
     
     
         13 . The turbine blade of  claim 12 , wherein the first side wall comprises a pressure side wall, and the second side wall comprises a suction side wall. 
     
     
         14 . The turbine blade of  claim 12 , wherein the first side wall comprises a suction side wall, and the second side wall comprises a pressure side wall. 
     
     
         15 . The turbine blade of  claim 12 , further comprising a tip shelf recessed into the tip endwall, wherein the tip shelf comprises the tip surface. 
     
     
         16 . The turbine blade of  claim 15 , wherein the tip surface is contiguous with the first side surface. 
     
     
         17 . The turbine blade of  claim 12 , wherein the tip outlet directs the cooling fluid out of the airfoil along an axis that is angled relative to the first side surface. 
     
     
         18 . The turbine blade of  claim 12 , wherein the microcircuit cavity comprises a cavity length that extends radially through the first side wall, the side wall outlet is one of a plurality of side wall outlets that direct a portion of the cooling air in the microcircuit cavity out of the airfoil to film cool the first side surface, and the side wall outlets are arranged radially along the cavity length. 
     
     
         19 . The rotor blade of  claim 12 , further comprising a cooling passage that directs cooling fluid in the main cavity out of the airfoil to film cool one of the first side surface and the tip surface. 
     
     
         20 . The rotor blade of  claim 12 , further comprising a protrusion extending into the microcircuit cavity.