Patent attributes
A turbine blade with improved tip cooling includes an airfoil having a tip cap and a tip wall extending outwardly from the tip cap. A recessed portion of the tip wall forms a tip shelf. At least one tip shelf hole extends through the tip shelf in flow communication with an internal airfoil cooling circuit. At least one tip wall opening extends through the recessed portion of the tip wall radially outward of the tip shelf in flow communication with the internal cooling circuit. The recessed tip wall portion may be tapered from a wider base to a minimum thickness. In a cooling method, cooling air channeled through the tip wall openings joins and mixes with a stream of hot combustion gases downstream of where cooling air channeled through the tip shelf openings joins and mixes with the stream of hot gasses to enhance convection cooling of the blade tip. A system for cooling a blade includes at least one tip shelf hole and at least one tip wall opening for channeling cooling air from an internal cooling circuit toward a stream of hot combustion gases for improved cooling of at least the blade tip.