Counter-vortex paired film cooling hole design

Abstract

An apparatus for use in a gas turbine engine includes a wall defining an exterior face, a first film cooling passage extending through the wall for providing film cooling to the exterior face of the wall, and a second film cooling passage extending through the wall adjacent to the first film cooling passage for providing film cooling to the exterior face of the wall. The first film passage includes a first vortex-generating structure for inducing a vortex in a first rotational direction in a cooling fluid passing therethrough, and the second film passage includes a second vortex-generating structure for inducing a vortex in a second rotational direction in a cooling fluid passing therethrough. The first and second rotational directions are substantially opposite one another.

1 . An apparatus for use in a gas turbine engine, the apparatus comprising:
 a wall defining an exterior face;   a first film cooling passage extending through the wall for providing film cooling to the exterior face of the wall, wherein the first film passage includes a first vortex-generating structure for inducing a vortex in a first rotational direction in a cooling fluid passing therethrough; and   a second film cooling passage extending through the wall adjacent to the first film cooling passage for providing film cooling to the exterior face of the wall, wherein the second film passage includes a second vortex-generating structure for inducing a vortex in a second rotational direction in a cooling fluid passing therethrough, and wherein the first and second rotational directions are substantially opposite one another.   
   
   
       2 . The apparatus of  claim 1 , wherein the first vortex-generating structure comprises a first helical rib disposed along an interior surface of the first film cooling passage. 
   
   
       3 . The apparatus of  claim 2 , wherein the second vortex-generating structure comprises a second helical rib disposed along an interior surface of the second film cooling passage, and wherein the first and second helical ribs of the first and second vortex-generating structures wind about respective central axes in opposite directions. 
   
   
       4 . The apparatus of  claim 1 , wherein the first and second vortex-generating structures are configured as mirror images of one another. 
   
   
       5 . The apparatus of  claim 1 , wherein the first and second film cooling passages have respective first and second outlets closely spaced from each other along the exterior face of the wall. 
   
   
       6 . The apparatus of  claim 5 , wherein the first and second film cooling passages define respective first and second central axes, wherein the first film cooling passage defines a first diameter, and wherein the first and second central axes are spaced from each other by a distance less than or equal to approximately ten times the first diameter. 
   
   
       7 . The apparatus of  claim 1 , wherein the first and second film cooling passages are both substantially cylindrically-shaped. 
   
   
       8 . The apparatus of  claim 1 , wherein the first and second film cooling passages are arranged substantially parallel to each other. 
   
   
       9 . The apparatus of  claim 1 , wherein the first and second rotational directions are arranged to flow generally toward the exterior face of the wall at a location where the vortexes adjoin each other. 
   
   
       10 . An apparatus for use in a gas turbine engine, the apparatus comprising:
 a wall defining an exterior face;   a pair of closely spaced film cooling passages extending through the wall for providing film cooling to the exterior face of the wall, the pair comprising:
 a first film cooling passage extending to a first outlet on the exterior face of the wall, wherein the first film passage includes a first helically-shaped vortex-generating structure disposed along an interior surface of the first film cooling passage for inducing a vortex in a first rotational direction in a cooling fluid passing therethrough; and 
 a second film cooling passage extending to a second outlet on the exterior face of the wall, wherein the second film passage includes a second helically-shaped vortex-generating structure disposed along an interior surface of the second film cooling passage for inducing a vortex in a second rotational direction in a cooling fluid passing therethrough. 
   
   
   
       11 . The apparatus of  claim 10 , wherein the first and second vortex-generating structures are configured as substantially mirror images of each other. 
   
   
       12 . The apparatus of  claim 10 , wherein the first and second rotational directions are arranged to flow generally toward the exterior face of the wall at a location where the vortexes adjoin each other. 
   
   
       13 . The apparatus of  claim 10 , wherein the first and second film cooling passages define respective first and second central axes, wherein the first film cooling passage defines a first diameter, and wherein the first and second central axes are spaced from each other by a distance less than or equal to approximately ten times the first diameter. 
   
   
       14 . The apparatus of  claim 10 , wherein the first and second film cooling passages are both substantially cylindrically-shaped. 
   
   
       15 . The apparatus of  claim 10 , wherein the first and second film cooling passages extend substantially parallel to each other through the wall. 
   
   
       16 . The apparatus of  claim 10 , wherein the first and second rotational directions are substantially opposite one another. 
   
   
       17 . A method of film cooling a gas turbine engine component exposed to a hot fluid stream, the method comprising:
 directing a cooling fluid into a first film cooling passage of the component;   passing the cooling fluid over at least one first vortex-generating structure to rotate a portion of the cooling fluid within the first film cooling passage in a first rotational direction;   directing a cooling fluid into a second film cooling passage of the component;   passing the cooling fluid over at least one second vortex-generating structure to rotate a portion of the cooling fluid within the second film cooling passage in a second rotational direction that counter-rotates with respect to the first rotational direction;   ejecting the cooling fluid rotating in the first rotational direction out of a first outlet in fluid communication with the first film cooling passage;   ejecting the cooling fluid rotating in the second rotational direction out of a second outlet in fluid communication with the second film cooling passage, wherein the counter-rotating cooling fluid ejected from the first and second outlets forms a contiguous cooling film jet; and   passing the counter-rotating cooling film jet along an exterior surface of the component to provide film cooling therealong.   
   
   
       18 . The method of  claim 17 , wherein the counter-rotation of the film cooling jet concentrates mixing with the hot fluid stream at a region spaced away from the exterior surface of the component.