Transpiration-cooled article having nanocellular foam

Abstract

A transpiration-cooled article includes a body wall that has first and second opposed surfaces. The first surface is adjacent a passage that is configured to receive a pressurized cooling fluid. At least a portion of the body wall includes a nanocellular foam through which the pressurized cooling fluid from the passage can flow to the second surface. The article can be an airfoil that includes an airfoil body that has an internal passage and an outer gas-path surface. At least a portion of the airfoil body includes a nanocellular foam through which cooling fluid from the internal passage can flow to the gas-path surface.

What is claimed is: 
     
         1 . A transpiration-cooled airfoil comprising:
 an airfoil body that includes an internal passage and an outer gas-path surface, and   at least a portion of the airfoil body includes a nanocellular foam through which cooling fluid from the internal passage can flow to the gas-path surface.   
     
     
         2 . The transpiration-cooled article as recited in  claim 1 , wherein the airfoil body includes at least one discrete window of the nanocellular foam surrounded by solid walls. 
     
     
         3 . The transpiration-cooled article as recited in  claim 1 , wherein the nanocellular foam has an average pore size of 10 micrometers to 100 nanometers. 
     
     
         4 . The transpiration-cooled article as recited in  claim 1 , wherein the nanocellular foam has a porosity of 5-95%. 
     
     
         5 . The transpiration-cooled article as recited in  claim 4 , wherein the nanocellular foam has a pore volume of 0.01-0.1 milliliters per gram. 
     
     
         6 . The transpiration-cooled airfoil as recited in  claim 1 , wherein the airfoil body includes a leading edge and a trailing edge and a first sidewall and a second sidewall that is spaced apart from the first sidewall, the first sidewall and the second sidewall join the leading edge and the trailing edge and at least partially define the internal passage, and the nanocellular foam is located in the first sidewall, and the first sidewall is a suction side of the airfoil body. 
     
     
         7 . The transpiration-cooled airfoil as recited in  claim 1 , wherein the airfoil body includes a leading edge and a trailing edge and a first sidewall and a second sidewall that is spaced apart from the first sidewall, the first sidewall and the second sidewall join the leading edge and the trailing edge and at least partially define the internal cavity, the airfoil body extending from a platform end wall, and the nanocellular foam is in the platform end wall. 
     
     
         8 . A transpiration-cooled article comprising:
 a body wall having first and second opposed surfaces, the first surface is adjacent a passage that is configured to receive a pressurized cooling fluid, and   at least a portion of the body wall includes a nanocellular foam through which the pressurized cooling fluid from the passage can flow to the second surface.   
     
     
         9 . The transpiration-cooled airfoil as recited in  claim 8 , wherein the nanocellular foam is metallic. 
     
     
         10 . The transpiration-cooled airfoil as recited in  claim 9 , wherein the nanocellular foam is selected from the group consisting of nickel, tantalum, tungsten, rhenium, niobium, hafnium, platinum, ruthenium, rhodium, palladium, osmium, iridium, copper, iron, molybdenum, yttrium, manganese, aluminum, chromium, cobalt, and combinations thereof. 
     
     
         11 . The transpiration-cooled airfoil as recited in  claim 8 , wherein the nanocellular foam is ceramic material. 
     
     
         12 . The transpiration-cooled airfoil as recited in  claim 11 , wherein the ceramic material is selected from the group consisting of oxides, nitrides, carbides, borides, silicides, and combinations thereof. 
     
     
         13 . The transpiration-cooled airfoil as recited in  claim 11 , wherein the ceramic material is a ternary ceramic. 
     
     
         14 . The transpiration-cooled airfoil as recited in  claim 11 , wherein the ceramic material is selected from the group consisting of manganese oxide, zinc oxide, silicon carbide, aluminum oxide, and combinations thereof. 
     
     
         15 . The transpiration-cooled airfoil as recited in  claim 8 , wherein the body wall includes at least one discrete window of the nanocellular foam surrounded by solid wall. 
     
     
         16 . The transpiration-cooled airfoil as recited in  claim 8 , wherein the nanocellular foam has an average pore size of less than 10 micrometers. 
     
     
         17 . The transpiration-cooled airfoil as recited in  claim 16 , wherein the nanocellular foam has a porosity of 5-95%. 
     
     
         18 . The transpiration-cooled airfoil as recited in  claim 17 , wherein the nanocellular foam has a pore volume of 0.01-0.1 milliliters per gram. 
     
     
         19 . A transpiration-cooled system comprising:
 a passage configured to receive a pressurized cooling fluid;   a wall having first and second opposed surfaces, the first surface is adjacent the passage, and the second surface is a gas-path surface that has a design boundary flow condition,   at least a portion of the wall includes a nanocellular foam through which the pressurized cooling fluid from the passage can flow to the second surface, and the nanocellular foam has controlled pore characteristics with respect to a design discharge velocity of the pressurized cooling fluid from the nanocellular foam and the design boundary flow condition.