GAS TURBINE ENGINE AIRFOIL TIP RECESSES

摘要

A gas turbine engine airfoil extending from an airfoil base to an airfoil tip at a free end of the airfoil and from a leading edge to a trailing edge of the airfoil has at least one recess extending into and circumferentially completely through the airfoil tip and located inwardly of the leading and trailing edges. The recess is located in an area of the airfoil tip subject to high tip vibratory stress and or rubs and may be a circular scallop having a scallop radius and a maximum depth of a few mills in a range of about 0.005-0.01 inches as measured from a nominal tip edge without the recess. The airfoil may be on a radial blade, a stator vane, or an impeller blade. An annular tip seal may surround a plurality of such airfoil tips with an airfoil tip clearance therebetween.