Combustor liner cooling at transition duct interface and related method

A combustor assembly for a turbine comprising:

• a combustor including a combustor liner;
• a first flow sleeve surrounding said combustor liner forming a first substantially axially-extending flow annulus radially therebetween, said first flow sleeve having a first plurality of apertures formed about a circumference thereof for directing compressor discharge air as cooling air radially into said first flow annulus;
• a transition piece connected to said combustor liner, said transition piece adapted to carry hot combustion gases to the turbine;
• a second flow sleeve surrounding said transition piece forming a second substantially axially-extending flow annulus radially therebetween, said second flow sleeve having a second plurality of apertures for directing compressor discharge air as cooling air radially into said second flow annulus, said first substantially axially-extending flow annulus connecting with said second substantially axially-extending flow annulus;
• a resilient annular seal structure disposed radially between an aft end of said combustor liner and a forward end of said transition piece, said resilient annular seal structure configured to form a first annular cavity radially between said forward end of said transition piece and said aft end of said combustor liner;
• and
• at least one transfer tube radially extending from said second flow sleeve through said second flow annulus to said transition piece, and arranged to supply compressor discharge cooling air radially from an area outside said first and second substantially axially-extending flow annuli directly to said resilient annular seal structure and to said aft end of said combustor liner;
• wherein said forward end of said transition piece is formed with a first annular cooling plenum, and wherein, in use, said at least one transfer tube supplies compressor discharge cooling air to said first annular cooling plenum which, in turn, supplies the compressor discharge cooling air to said resilient annular seal structure and to said aft end of said combustor liner.