Film coolant passage with swirl diffuser

摘要

The wall of a hollow turbine airfoil has a longitudinally extending coolant outlet slot in its external surface which intersects, along its length, a longitudinally extending cylindrical channel within the wall. Metering passages extend from the inside surface of the airfoil wall to the cylindrical channel and direct a metered amount of coolant into the channel in a manner which results in a swirling motion being imparted to the fluid as the fluid diffuses within the channel. The coolant is thereupon ejected from the channel through the slot in the external surface as a film on the external surface of the airfoil along the length of the slot. The swirling of the fluid within the cylindrical channel helps diffuse the fluid such that the outlet slot becomes completely filled with coolant, whereby a film of coolant is created on the airfoil surface downstream of the slot over the full length of the slot.