Cooled transition duct for a gas turbine engine

A transition duct for a gas turbine engine for conducting hot combustion gas along a direction of flow between a combustor outlet and a turbine inlet, the transition duct comprising:

• a first panel comprising a plurality of subsurface cooling channels disposed generally parallel to the direction of flow of the combustion gas;
• a second panel comprising a plurality of subsurface cooling channels disposed generally parallel to the direction of flow of the combustion gas;
• the first panel and second panel each formed to comprise corners disposed generally parallel to the direction of flow to shape the respective panels into generally U-shapes with respective internal cooling channels extending along the corners generally parallel to the direction of flow of the combustion gas and effective to cool the entire respective corner;
• and
• first side and second side welds joining the first panel to the second panel along respective opposed edges to define a hot combustion gas passageway having an inlet end of generally circular cross-section conforming to a shape of the combustor outlet and an exit end of generally rectangular cross-section conforming to a shape of the turbine inlet, the first side and second side welds being disposed remote from the corners.

A gas turbine engine comprising:

• a plurality of combustors each comprising an outlet comprising a circular cross-section;
• a turbine comprising an inlet comprising an annular cross-section;
• and
• a plurality of transition ducts interconnecting respective combustor outlets with the turbine inlet, each transition duct comprising an inlet comprising a circular cross-section for mating with a respective combustor outlet and comprising a generally rectangular outlet for mating with an arcuate portion of the turbine inlet;
• adjacent transition duct outlets being separated by a gap G in a cold condition, gap G being adequate to accommodate thermal growth along an arcuate width W of the respective transition ducts;
• a plurality of cooling channels formed through each transition duct and spaced along the entire arcuate width W of each transition duct to effectively cool the entire arcuate width W of each transition duct to control the thermal growth.