Patent ID: 8109099

Claim:
A combustion duct for a gas turbine engine comprising: a combustion liner to receive products of combustion, and deliver them downstream toward a turbine rotor; an outer housing positioned radially outwardly of said combustion liner; a flow sleeve positioned radially intermediate said outer housing and said combustion liner, said flow sleeve defining a chamber, radially outwardly of said flow sleeve, for receiving cooling air, and a plurality of holes through said flow sleeve to deliver cooling air against an outer periphery of said combustion liner; a plurality of tabs associated with at least some of said holes in said flow sleeve, said tabs being positioned to extend radially inwardly on a downstream side of said holes, and said tabs urging air that has passed through said holes back upstream; said plurality of tabs being associated with a ring that extends for more than 270° about a central axis of said flow sleeve; said ring having a cylindrical base within said flow sleeve, and said tabs extending radially inwardly for a greater distance than said base; said base having base holes to correspond with said holes in said flow sleeve; said flow sleeve and its plurality of holes being a separate part from said ring and said base holes; said base holes in said ring surrounding said holes in said flow sleeve; said plurality of tabs being circumferentially spaced; and there being spaces circumferentially intermediate said plurality of circumferentially spaced tabs.