A Three Dimensional Computational Study of Windage Heating Within an Axial Compressor Stator Well

Abstract

Shrouded stator blades are sometimes used to prevent vibration problems, but more often they are used to eliminate blade over-tip leakage flows. A trench or recess referred to as a stator well must be provided in the rotor drum assembly in order to accommodate the stator shroud. This paper presents a computational study of the flow and windage generation within an axial compressor stator well. Windage heating levels for a three dimensional compressible solution of flow through a geometry comprising upstream and downstream stator well cavities, labyrinth seal and the stator blade row are quantified. The potential for hot fluid ejected from the upstream stator well seal into the mainstream annulus, migrating through the blade row and being re-ingested at the downstream stator well seal for further windage heating has been studied using a layered temperature boundary condition at entry to the stator row. The possible reconfiguration of detailed stator well geometry has been explored to identify options for controlling flow rate and reducing windage levels, other than controlling clearances, yielding a 9% reduction in flow rate and a 9% reduction in windage heating.