Turbine Engine Components with Near Surface Cooling Channels and Methods of Making the Same

Abstract

A turbine airfoil has an airfoil-shaped core and a skin extending about the outer peripheral surface of the core. The core and/or the skin are configured such that a plurality of cooling channels is formed between them. In one embodiment, the cooling channels are formed by a plurality of radially extending channels in the core. In another embodiment, the cooling channels are formed by providing a wave-shaped skin such that, when the skin is attached to the outer peripheral surface of the core, the cooling channels can be formed in the space between the outer peripheral surface of the core and each wave of the skin. Such airfoil constructions can allow the inclusion of different materials in the airfoil. Further, such constructions can allow greater flexibility in the formation of cooling channels. Moreover, such constructions can help to achieve thinner outer walls and near surface cooling of the airfoil.

1 . A turbine vane comprising:
 a core having an outer peripheral surface, the core having an airfoil shape, a plurality of channels formed in the core such that each channel opens to the outer peripheral surface of the core, the channels extending substantially radially so as to be elongated in the radial direction;   a first platform attached to the core;   a non-permeable skin having a hollow interior, the skin being airfoil-shaped and having an inner peripheral surface and an outer peripheral surface, the skin being sized so that the core can be received in the hollow interior of the skin; and   a second platform attached to the skin,   the core being received in the hollow interior of the skin such that the outer peripheral surface of the core engages the inner peripheral surface of the skin such that a plurality of generally radial cooling channels are formed between the channels in the core and the inner peripheral surface of the skin, the skin being attached to the core over at least a portion of the engaging surfaces of the outer peripheral surface of the core and the inner peripheral surface of the skin.   
     
     
         2 . The turbine vane of  claim 1  wherein the first platform is unitary with the core, and wherein the second platform is unitary with the skin. 
     
     
         3 . The turbine vane of  claim 1  wherein the core includes at least one transverse channel extending in a direction that is generally transverse to the radially extending channels, the at least one transverse channel connects between two neighboring radially extending channels, whereby fluid communication is permitted between the two neighboring radially extending channels. 
     
     
         4 . The turbine vane of  claim 1  wherein the core is made of a material that has a higher coefficient of thermal expansion than the material of the skin. 
     
     
         5 . The turbine vane of  claim 1  wherein the outer peripheral surface of the core substantially matingly engages the inner peripheral surface of the skin. 
     
     
         6 . The turbine vane of  claim 1  wherein the skin includes a distal end, wherein the distal end engages the first platform. 
     
     
         7 . The turbine vane of  claim 6  wherein the distal end of the skin is attached to the first platform. 
     
     
         8 . The turbine vane of  claim 1  wherein the core has an associated radial length, wherein each of the channels extends more than 50 percent of the radial length of the core. 
     
     
         9 . A method of forming a turbine vane comprising the steps of:
 forming an airfoil-shaped core having an outer peripheral surface;   forming a plurality of channels in the core such that each channel opens to the outer peripheral surface of the core, the channels extending substantially radially so as to be elongated in the radial direction;   forming a non-permeable, airfoil-shaped skin having a hollow interior, the skin having an inner peripheral surface and an outer peripheral surface, the skin being sized so that the core can be received in the hollow interior of the skin;   bringing the core and the skin together such that the core is received in the hollow interior of the skin such that the outer peripheral surface of the core engages the inner peripheral surface of the skin to thereby form a plurality of generally radial cooling channels between the channels in the core and the inner peripheral surface of the skin; and   attaching the skin to the core over at least a portion of the engaging surfaces of the outer peripheral surface of the core and the inner peripheral surface of the skin.   
     
     
         10 . The method of  claim 9  further including the steps of:
 forming a first platform together with the core, whereby a unitary structure is formed; and 
 forming a second platform together with the skin, whereby a unitary structure is formed. 
 
     
     
         11 . The method of  claim 10  wherein the skin includes a distal end and wherein, after the step of bring the core and the skin together, the distal end of the skin engages the first platform, and further including the step of:
 attaching the distal end of the skin to the first platform. 
 
     
     
         12 . A turbine engine component comprising:
 a core having an outer peripheral surface;   a skin extending about at least a portion of the outer peripheral surface of the core, the skin being wavy so as to have a plurality of peaks and valleys, the skin engaging the core such that the valleys of the skin substantially abut the outer peripheral surface of the core, the valleys being attached to the core such that a plurality of elongated cooling channels are formed in the space between the outer peripheral surface of the core and each wave of the skin.   
     
     
         13 . The turbine engine component of  claim 12  wherein the skin is made of oxide dispersion strengthened alloy. 
     
     
         14 . The turbine engine component of  claim 12  wherein the attachment between the valleys of the skin and the outer peripheral surface of the core is continuous in the radial direction along each valley, whereby each of the cooling channels is isolated from the other cooling channels. 
     
     
         15 . The turbine engine component of  claim 12  wherein the attachment between the valleys of the skin and the outer peripheral surface of the core is intermittent in the radial direction along each valley, whereby fluid communication is permitted between at least two of the cooling channels. 
     
     
         16 . The turbine engine component of  claim 12  wherein the core is airfoil-shaped, whereby the turbine engine component is an airfoil. 
     
     
         17 . The turbine engine component of  claim 12  wherein at least one of the cooling channels is different from the other cooling channels in at least one respect. 
     
     
         18 . The turbine engine component of  claim 12  further including a coolant received in at least one of the cooling channels. 
     
     
         19 . The turbine engine component of  claim 12  wherein the skin has an uncoated outer side, whereby the uncoated skin forms an outermost surface of the turbine engine component. 
     
     
         20 . The turbine engine component of  claim 12  wherein the skin has an outer side that is coated with a thermal insulating material, whereby the thermal insulating material forms an outermost surface of the turbine engine component.