Method of forming cooling apertures in airfoil-shaped blades

摘要

Apertures in airfoils for use in a hot gas path of a turbine are formed from the interior of the airfoil to the exterior in circumstances where line-of-sight access from locations external to the nozzle is inhibited or prohibited. A water jet nozzle head is disposed in a cavity within the airfoil and angled at the desired inclination to cut an angled hole through the airfoil wall using a water jet and abrasive material contained in the water. A protective device, e.g., a backstop or shield, is provided on the outside of the nozzle to prevent damage to other portions of the nozzle from the water jet which would otherwise impinge but for the protective device.