Clearance control for the turbine of a gas turbine engine

摘要

An aerodynamic buffer zone in the gap 54 between the tip 30 of an air cooled axial flow turbine blade of a gas turbine engine and its surrounding shroud or seal (outer air seal) 56 is created by discretely discharging a high velocity stream of cooling air from the tip of the blade in a judicious direction. The stream is angularly oriented relative to the plane of rotation of the turbine so that it is discharged in the gap in the direction of the pressure side of the turbine and preferably at between a 15-45{ angle relative to the flat surface of the tip of the blade.