Single skin combustor heat transfer augmenters

Abstract

A combustor for a gas turbine engine comprises a single skin liner defining a combustion chamber. The single skin liner has an inner surface facing the combustion chamber and an outer surface exposed to a coolant flow discharged in a plenum extending from the outer surface of the single skin liner to the engine casing. Cooling holes extend through the single skin liner. Open flow guiding channels are provided on the outer surface of the single skin liner, the open flow guiding channels being uncovered and aligned with the flow of air over the outer surface of the single skin liner.

1 . A single skin combustor for a gas turbine engine, the single skin combustor comprising: a single skin liner defining a combustion chamber, the single skin liner having an inner surface exposed to the combustion chamber and an outer surface exposed to an open-channel flow of air in a plenum circumscribed by a gas generator case of the gas turbine engine, the outer surface of the single skin liner being an outermost surface of the combustor, cooling holes extending through the single skin liner, and open flow guiding channels provided on the outer surface of the single skin liner, the open flow guiding channels being uncovered and aligned with the flow of air over the outer surface of the single skin liner. 
     
     
         2 . The single skin combustor defined in  claim 1 , wherein at least some of the open flow guiding channels define a curve to in use redirect a portion of the flow of air to a predetermined hot spot region. 
     
     
         3 . The single skin combustor defined in  claim 2 , wherein heat transfer augmenters are provided in the hot spot region, the heat transfer augmenters projecting from the outer surface of the single skin liner. 
     
     
         4 . The single skin combustor defined in  claim 3 , wherein the heat transfer augmenters are selected from the group consisting of: pin fins, fins, trip strips, dimples and knurled surfaces. 
     
     
         5 . The single skin combustor defined in  claim 1 , wherein the open flow guiding channels are defined between pairs of adjacent ribs projecting from the outer surface of the single skin liner. 
     
     
         6 . The single skin combustor defined in  claim 5 , wherein at least some of the ribs are curved. 
     
     
         7 . The single skin combustor defined in  claim 5 , wherein the ribs are non-uniformly distributed on the outer surface of the single skin liner to in use direct more air towards predetermined hot spot regions of the single skin liner. 
     
     
         8 . The single skin combustor defined in  claim 5 , wherein pin fins project from the outer surface of the single skin liner downstream from the ribs relative to the flow of air over the outer surface. 
     
     
         9 . The single skin combustor defined in  claim 8 , wherein a circumferential row of fins extends from the outer surface of the single skin liner downstream from the pin fins. 
     
     
         10 . The single skin combustor defined in  claim 9 , wherein a circumferential row of dilution holes is provided downstream of the circumferential row of fins. 
     
     
         11 . The single skin combustor defined in  claim 3 , wherein the heat transfer augmenters are an extension of a base metal of the single skin liner. 
     
     
         12 . The single skin combustor defined in  claim 11 , wherein each heat transfer augmenter comprises successive layers of sequentially deposit material on a sheet metal base. 
     
     
         13 . The single skin combustor defined in  claim 3 , wherein the density of heat transfer augmenters varies over the outer surface of the single skin liner. 
     
     
         14 . A gas turbine engine comprising a gas generator case, a combustor disposed within the gas generator case, the combustor having a single skin liner circumscribing a combustion chamber, the single skin liner and the gas generator case defining therebetween a plenum, the single skin liner having an outer surface exposed to a flow of air discharged in the plenum and an inner surface exposed to combustion gases in the combustion chamber, cooling holes defined in the single skin liner, the cooling holes fluidly liking the plenum to the combustion chamber, and heat transfer augmenters provided on the outer surface of the single skin liner, the heat transfer augmenters including ribs configured to redirect the flow of air from a first direction to a second direction. 
     
     
         15 . The gas turbine engine defined in  claim 14 , wherein the ribs are oriented towards a predetermined hot spot region of the single skin liner. 
     
     
         16 . The gas turbine engine defined in  claim 15 , wherein the heat transfer augmenters further comprise turbulators in the predetermined hot spot region, the turbulators projecting from the outer surface of the single skin liner. 
     
     
         17 . The gas turbine engine defined in  claim 16 , wherein the turbulators are selected from the group consisting of: pin fins, trip strips, dimples and knurled surfaces. 
     
     
         18 . The gas turbine engine defined in  claim 15 , wherein the ribs are curved. 
     
     
         19 . The gas turbine engine defined in  claim 14 , wherein the heat transfer augmenters further comprise a plurality of pin fins downstream from the ribs relative to the flow of air over the outer surface of the single skin liner, and a set of fins downstream from the pin fins, the pin fins and the fins projecting into the plenum. 
     
     
         20 . The gas turbine engine defined in  claim 14 , wherein the single skin liner is provided in the form of a metal sheet, and wherein the heat transfer augmenters include free standing ribs projecting from the outer surface of the metal sheet.