GAS TURBINE AIRFOIL COOLING

摘要

PURPOSE: An airfoil with improved High Pressure Turbine (HPT) aerodynamic efficiency is provided which improves vane and blade stage efficiency by reducing energy losses due to secondary flow mixing. CONSTITUTION: An air cooling system for a turbine section airfoil, a gas turbine engine have a mainstream gas path therethrough comprising coolant air bleed means from a compressor section of the gas turbine engine to the airfoil; the airfoil including an airfoil wall having an exterior airfoil shape and defining an internal cavity; the airfoil including a platform at an end of the airfoil; the airfoil including an aft section defining a trailing edge, an insert tube in the cavity extending from the platform and communicating with the coolant air bleed means to pass a portion of the coolant air through the insert tube and into the cavity; air exhaust slots at the trailing edge and along the span of the airfoil across the mainstream gas path for exhausting gas from the cavity to the mainstream gas path; the airfoil further communicating with the coolant air bleed means to direct another portion of the coolant air to impinge on the platform, the improvement comprising an opening defined in the platform to communicate with the cavity in the aft section between the insert tube and the exhaust slots in the aft section of the airfoil to exhaust the portion of the coolant air impinged on the platform through the exhaust slots along with the portion of the coolant air passed into the cavity through the insert tube.