Film effectiveness enhancement using tangential effusion

Abstract

Film effectiveness enhancement is provided by a plurality of tangentially angled effusion holes in a combustor liner. The effusion holes positioned in the initial flow region at the start of the panel have a tangential angle between about 75° and about 90° to the combustor axis. The tangential angle of the effusion holes positioned downstream from the initial flow region is gradually reduced to a value corresponding to the bulk swirl of the combustor internal flow or to zero so that the effusion hole orientation at the end of the panel corresponds to that of convention effusion.

1 . An apparatus for an effusion cooled component comprising: 
 a plurality of initial effusion hole openings positioned in an initial flow region of said effusion cooled component, at least one of said initial effusion hole openings positioned such that a longitudinal line of said effusion cooled component and a centerline of said at least one initial effusion hole opening forms an initial hole tangential angle of between about 75′ and about 90°; and    a plurality of transition openings positioned downstream from said initial effusion hole openings, at least one of said transition openings positioned such that a longitudinal line of said effusion cooled component and a centerline of said at least one transition opening forms a transition hole tangential angle, said transition hole tangential angle having a value less than a value of said initial hole tangential angle.    
   
   
       2 . (canceled)  
   
   
       3 . The apparatus of  claim 1 , wherein said transition hole tangential angle is inversely proportional to a distance between said transition opening and an upstream end of said effusion cooled component.  
   
   
       4 . The apparatus of  claim 1 , wherein said plurality of transition openings comprises between about five and about ten circumferential rows of transition openings.  
   
   
       5 . The apparatus of  claim 1 , wherein said effusion cooled component comprises a combustor.  
   
   
       6 . The apparatus of  claim 5 , wherein said combustor comprises an annular combustor liner.  
   
   
       7 . The apparatus of  claim 1 , wherein said plurality of initial effusion hole openings comprises between about five and about ten circumferential rows of initial effusion hole openings.  
   
   
       8 . The apparatus of  claim 1 , wherein each said initial effusion hole opening has a diameter between about 0.015 and about 0.030 inches.  
   
   
       9 . The apparatus of  claim 1 , wherein said initial hole tangential angle is between about 75° and about 85°.  
   
   
       10 . The apparatus of  claim 1 , wherein said initial hole tangential angle is between about 80° and about 90°.  
   
   
       11 . An effusion array for a component comprising: 
 a plurality of effusion hole openings through said component, said plurality of effusion hole openings positioned such that (i) a plurality of initial effusion hole openings are formed in an initial flow region of said component and (ii) at least five circumferential rows of transition openings are formed in a transition region of said component, said plurality of initial effusion hole openings capable of providing an effusion flow at a tangential angle of between about 75° and about 90° to an axis of said component, said at least five circumferential rows of transition openings capable of providing an effusion flow at a tangential angle of less than that of said plurality of initial effusion hole openings.    
   
   
       12 . (canceled)  
   
   
       13 . The effusion array of  claim 13 , wherein each said transition opening has a diameter between about 0.01 and about 0.05 inches.  
   
   
       14 . The effusion array of  claim 13 , wherein said at least five circumferential rows of transition openings comprise between about 5 and about 10 circumferential rows of transition openings.  
   
   
       15 . The effusion array of  claim 11 , wherein said plurality of initial effusion hole openings comprises between about 5 and about 10 circumferential rows of initial effusion hole openings.  
   
   
       16 . The effusion array of  claim 11 , wherein said plurality of initial effusion hole openings are capable of providing an effusion flow at a tangential angle of between about 75° and about 85° to an axis of said component.  
   
   
       17 . The effusion array of  claim 11 , wherein said component comprises a combustor.  
   
   
       18 . The effusion array of  claim 11 , wherein said component comprises an annular combustor liner.  
   
   
       19 . The effusion array of clam  11 , wherein a density of said initial effusion hole openings is between about 10 and about 100 holes/in 2 .  
   
   
       20 . A component requiring cooling comprising: 
 at least two circumferential rows of initial effusion hole openings through said component, each said initial effusion hole opening positioned such that a longitudinal line of said component and a centerline of said initial effusion hole opening forms an initial hole tangential angle of between about 80° and about 90°; and    at least five circumferential rows of transition openings positioned downstream from said initial effusion hole openings, each said transition opening positioned such that a longitudinal line of said component and a centerline of said transition opening forms a transition hole tangential angle, said transition hole tangential angle having a value less than a value of said initial hole tangential angle.    
   
   
       21 . The apparatus of  claim 20 , wherein said at least two circumferential rows of initial effusion hole openings comprise between about 5 and about 10 circumferential rows of initial effusion hole openings.  
   
   
       22 . The apparatus of  claim 20 , wherein said at least five circumferential rows of transition openings comprise between about 5 and about 10 circumferential rows of transition openings.  
   
   
       23 . A combustor for a gas turbine engine comprising: 
 an inner liner;    an outer liner positioned radially outward from said inner liner, said outer liner having at least about two circumferential rows of initial effusion hole openings there through and at least about five circumferential rows of transition openings downstream from said at least about two circumferential rows of initial effusion hole openings, said initial effusion hole openings having a tangential angle between about 75° and about 90° to an axis of said gas turbine engine; and    a dome positioned between and connected to said inner liner and said outer liner.    
   
   
       24 . The combustor of  claim 23 , wherein said inner liner comprises an annular combustor liner.  
   
   
       25 . (canceled)  
   
   
       26 . The combustor of  claim 23 , wherein said outer liner has at least about five circumferential rows of transition openings there through, each transition opening having a tangential angle inversely proportional to a distance between said transition opening and an upstream end of said outer liner.  
   
   
       27 . An effusion array for an annular combustor liner comprising: 
 at least three circumferential rows of initial effusion hole openings positioned in an initial flow region of said annular combustor liner, each initial effusion hole opening positioned such that a longitudinal line of said annular combustor liner and a centerline of said initial effusion hole opening forms an initial hole tangential angle of between about 75° and about 90°, each initial effusion hole opening having a diameter between about 0.015 and about 0.030 inches, each initial effusion hole opening forming an axial angle of between about 15° and about 30° with a surface of said annular combustor liner; and    at least five circumferential rows of transition openings positioned downstream from said initial effusion hole openings, each said transition opening positioned such that longitudinal line of said annular combustor liner and a centerline of said transition opening forms a transition hole tangential angle, said transition hole tangential angle having a value of less than a value of said initial hole tangential angle.    
   
   
       28 . A method of enhancing the film effectiveness for an effusion cooled component comprising the step of: 
 passing a first portion of effusion flow through a plurality of initial effusion hole openings in an initial flow region of said effusion cooled component, at least one said initial effusion hole opening positioned such that a longitudinal line of said effusion cooled component and a a centerline of said at least one initial effusion hole opening forms an initial hole tangential angle of between about 75° and about 90°; and    passing a second portion of effusion flow through a plurality of transition openings in a transition region of said effusion cooled component, at least one transition opening positioned such that longitudinal line of said effusion cooled component and a centerline of said at least one transition opening forms a transition hole tangential angle, said transition hole tangential angle less than said initial hole tangential angle.    
   
   
       29 . (canceled)  
   
   
       30 . The method of  claim 28 , wherein said step of passing a first portion of effusion flow provides a cooling film capable of protecting said initial flow region from a hot combustion flow through said effusion cooled component.