초록 ▼

The present invention provides active convection cooling through micro channels within or adjacent to a bond coat layer applied to the trailing edge of a turbine engine high pressure airfoil. When placed adjacent to or within a porous TBC, the micro channels additionally provide transpiration coolin

The present invention provides active convection cooling through micro channels within or adjacent to a bond coat layer applied to the trailing edge of a turbine engine high pressure airfoil. When placed adjacent to or within a porous TBC, the micro channels additionally provide transpiration cooling through the porous TBC. The micro channels communicate directly with at least one cooling circuit contained within the airfoil from which they receive cooling air, thereby providing direct and efficient cooling for the bond coat layer. Because the substrate includes an actively cooled flow path surface region that can reduce the cooling requirement for the substrate, the engine can run at a higher firing temperature without the need for additional cooling air, achieving a better, more efficient engine performance. In one embodiment, a metallic bond coat is added to an airfoil with pressure side bleed film cooling slots. The bond coat is grooved such that the grooves are structured, with at least one structured micro groove communicating with at least one cooling fluid supply contained within the airfoil. A TBC layer is applied, using a shadowing technique, over the structured grooves, resulting in the formation of hollow micro channels for the transport of the cooling fluid. In different embodiments, the location of the structured grooves, hence, the resulting micro channels are placed within the airfoil substrate at the substrate/bond coat interface or within the TBC layer.

대표청구항 ▼

1. A cooling system for actively cooling a flow path surface region of a gas turbine airfoil trailing edge extending into a gas flow path comprising:a substrate having a trailing edge first surface adjacent the gas flow path; a bond coat applied to the trailing edge first surface; at least one coati

1. A cooling system for actively cooling a flow path surface region of a gas turbine airfoil trailing edge extending into a gas flow path comprising:a substrate having a trailing edge first surface adjacent the gas flow path; a bond coat applied to the trailing edge first surface; at least one coating material overlying the bond coat, an outer portion of the coating material forming the gas flow path surface; at least one channel in the substrate, the channel extending through the substrate between a first and second end, the first end of the substrate channel terminating in proximity to the trailing edge first surface of the substrate adjacent to the flow path surface, the second end of the substrate channel in fluid communication with a cooling fluid supply; at least one micro channel formed by the shadowing of the at least one coating material to a structured micro groove positioned between the first surface of the substrate and the outer surface of the coating material in a generally axial direction, the micro channel extending substantially parallel to the first surface of the substrate for a predetermined length, the micro channel in fluid communication with the first end of the substrate channel; and, means for expelling cooling fluid from the micro channel.