Aft flowing serpentine airfoil cooling circuit with side wall

Abstract

A gas turbine engine hollow airfoil includes an airfoil outer wall having width wise spaced aparted pressure and suction side walls joined together at chordally spaced apart leading and trailing edges of the airfoil and extending longitudinally from a root to a tip. At least one internal aft flowing serpentine cooling circuit inside the airfoil has an exit that is positioned aft of the entrance so as to have a chordal flow direction afterwards from the leading edge to the trailing edge within the serpentine circuit. At least one longitudinally extending first side wall impingement chamber is in downstream fluid communication with the serpentine cooling circuit within the airfoil and positioned between one of the side walls, preferably the pressure side wall, and a first inner wall bounding the serpentine cooling circuit. Impingement cooling apertures are disposed in the first inner wall between one of the serpentine channels and the side wall impingement chamber. A first plurality of side wall film cooling holes may extend out from the first side wall impingement chamber through the pressure side wall. At least one tip cooling hole extending out of at least one of the impingement chambers may be disposed through a longitudinally outer tip wall of the tip of the airfoil.