Arrangement for preventing contamination and plugging of holes on tip of gas turbine blade

摘要

The internally cooled airfoil is for a blade of a turbine rotor of a gas turbine engine. The airfoil is subjected to the fluid working medium of the gas turbine engine and including a tip surface, a leading edge, a trailing edge and a pressure side. There is an annular shroud concentrically supported around the airfoil and defining with the tip surface a gap. The airfoil has wall for defining an internal passageway leading cooling air to a discharge port formed adjacent the tip of the airfoil in proximity to the pressure surface for creating a jet of cooling air egressing into the gap at a given angle for creating a blockage in the gap to seal the gap and prevent leakage of the fluid working medium from entering into the gap. There are members for guarding against the clogging of the discharge port including a cavity formed adjacent the discharge port and extending from the pressure surface to the portion of the wall means defining the discharge port that is furthest away from the pressure surface and extending the width of the discharge port.