Turbine airfoil with enhanced cooling

A vane for a turbine of a gas turbine engine comprising:

• first and second endwalls;
• and
• an airfoil comprising:
• an outer wall structure defining at least one inner cavity adapted to receive a cooling fluid, said wall structure comprising first and second cooling fluid path circuits, each of said circuits comprising:
• first and second metering openings spaced apart from one another, said first and second metering openings extending from an inner surface of said wall structure such that said first and second metering openings communicate with said at least one inner cavity;
• first and a second diffusion regions located downstream from said first and second metering openings and communicating respectively with said first and second metering openings;
• a third metering opening positioned downstream from said first and second diffusion regions and communicating with said first and second diffusion regions;
• and,
• a third diffusion region positioned downstream from said third metering opening for communicating with said third metering opening and extending to an exit in an outer surface of said wall structure.

An airfoil for a turbine of a gas turbine engine comprising:

• an outer wall structure defining at least one inner cavity adapted to receive a cooling fluid, said wall structure comprising at least one cooling fluid path circuit communicating with said at least one inner cavity comprising:
• at least one metering opening extending from an inner surface of said wall structure such that said metering opening communicates with said at least one inner cavity;
• at least one intermediate diffusion region communicating with said metering opening;
• an intermediate metering opening positioned downstream from said intermediate diffusion region and communicating with said intermediate diffusion region;
• and,
• an end diffusion region positioned downstream from said intermediate metering opening for communicating with said intermediate metering opening and extending to an exit in an outer surface of said wall structure.