Airfoil turn caps in gas turbine engines

A vane of a gas turbine engine comprising:

• a hollow body having a pressure side and a suction side and the hollow body having a first up-pass cavity and a first down-pass cavity, the hollow body having an inner diameter end and an outer diameter end, the first up-pass cavity including a first pressure side airfoil passage arranged along the pressure side of the hollow body and a first suction side airfoil passage arranged along the suction side of the hollow body, the first up-pass cavity having a flow direction from the inner diameter end toward the outer diameter end and the first down-pass cavity having a flow direction from the outer diameter end toward the inner diameter end, the first down-pass cavity defined between external walls of the pressure side and the suction side of the hollow body;
• a first airfoil platform arranged at the outer diameter end of the hollow body, the first airfoil platform having a gas path surface and a non-gas path surface, wherein the hollow body extends from the gas path surface of the first airfoil platform;
• a first up-pass cavity opening formed in the non-gas path surface of the first airfoil platform fluidly connected to the first up-pass cavity;
• a first down-pass cavity opening formed in the non-gas path surface of the first airfoil platform fluidly connected to the first down-pass cavity;
• and
• a first turn cap fixedly attached to the first airfoil platform on the non-gas path surface covering the first up-pass cavity opening and the first down-pass cavity opening of the first airfoil platform, the first turn cap having:
• exterior side walls, the exterior side walls extending between a forward-end of the turn cap and an aft-end of the turn cap;
• an exterior top wall extending between the exterior side walls and between the forward-end and the aft-end of the turn cap;
• and
• a first divider located within the first turn cap extending from the exterior top wall and positioned between the exterior side walls and defining a first suction-side turn passage between the exterior side wall and the first divider and a first pressure-side turn passage between the exterior side wall and the first divider, wherein the first divider fluidly separates the first pressure-side turn passage from the first suction-side turn passage within the first turn cap, wherein the first divider extends from the forward-end of the turn cap toward the aft-end of the turn cap and separates the first pressure-side turn passage and the first suction-side turn passage,
• wherein a merging chamber is formed in the turn cap proximate the aft-end of the turn cap,
• wherein, in operation, a fluid flow passes radially through the first pressure side airfoil passage of the first up-pass cavity into the first pressure-side turn passage proximate the forward-end of the turn cap and fluid flows radially through the first suction side airfoil passage of the first up-pass cavity into the first suction-side turn passage proximate the forward-end of the turn cap,
• wherein, in operation, the fluid flow flows axially once entering the respective first pressure-side turn passage and first suction-side turn passage toward the aft-end of the turn cap,
• wherein, in operation, the fluid flow passing-flows axially through the first suction side turn passage and the first pressure side turn passage and are merged at the merging chamber in an axial direction proximate the aft-end of the turn cap, and
• wherein, in operation, the fluid flow is turned from an axial flow to a radial flow within the merging chamber and directed radially into the first down-pass cavity of the hollow body.