Film cooled vanes and turbines

摘要

The film of cooling air adjacent the outer surface of the airfoil of a turbine of a gas turbine engine issuing from internally of the turbine subsequent to cooling is controlled by regulating the pressure ratio of the internal to external pressures by forming an internal chamber extending longitudinally in the turbine and having fixed orifices admitting cooling air therein bearing a predetermined relationship to the exit orifices forming the film of cooling air. By regulating this pressure ratio the diameter of the exit holes can be longer than heretofore designs for a given application so that they can be precast rather than drilled and can be arranged to give fuller coverage of films of cooling air on the outer surface of the airfoil.