Drilled cooling air openings in gas turbine components

A rotor blade for a gas turbine comprising:

• a hollow blade having outside walls and a tip cover, and having first and second internal guide walls arranged between the outside walls, said first and second guide walls being spaced apart from each other and each intersecting said tip cover, a central guide wall between the first and second guide walls, said central guide wall being spaced from said tip cover, thereby forming a cooling air passage extending in sequence between the first guide wall and the central guide wall and extending between the central guide wall and the tip cover and extending between the central guide wall and the second guide wall, the cooling air passage having flow stagnation zones adjacent the intersection between the tip coever and the respective first and second guide walls, and a plurality of openings drilled in an outside wall on the suction side of the blade in proximity to at least one of said flow stagnation zones, whereby cooling air is able to flow from the cooling air passage to the outside of the blade to obtain a more efficient cooling effect.

A rotor blade for a gas turbine comprising:

• a hollow blade having outside walls and a tip cover, and having first and second internal guide walls arranged between the outside walls, said first and second guide walls being spaced apart from each other and each intersecting said tip cover, a central guide wall between the first and second guide walls, said central guide wall being spaced from said tip cover, thereby forming a cooling air passage extending in sequence between the first guide wall and the central guide wall and extending between the central guide wall and the tip cover and extending between the central guide wall and second guide wall, the cooling air passage having flow stagnation zones adjacent the intersection between the tip cover and the respective first and second guide walls, and a plurality of openings in an outside wall arranged in proximity to at least one of said flow stagnation zones, the openings are cylindrical and extend perpendicular to the outside wall, the openings being spaced apart from each other by at least one diameter of the openings, and being arranged in rows, the openings being spaces at least 5 diameters of the openings from the tip cover and the openings being located adjacent the second guide wall, whereby cooling air is able to flow from the cooling air passage to the outside of the blade to obtain a more efficient cooling effect.