Aerodynamic Design and Performance of Aspirated Airfoils

TLDR

The paper examines how boundary‑layer aspiration affects the design and performance of turbomachinery airfoils. The authors use computational studies of a controlled diffusion cascade, two compressor stages, and a turbine exit guide vane to analyze how aspiration influences loading, loss, and blade design requirements. Results show that modest aspiration can sustain high loading across most of the blade span, though three‑dimensional end‑wall effects can reduce performance depending on loading level.

Abstract

The impact of boundary layer aspiration, or suction, on the aerodynamic design and performance of turbomachinery airfoils is discussed in this paper. Aspiration is studied first in the context of a controlled diffusion cascade, where the effect of discrete aspiration on loading levels and profile loss is computationally investigated. Blade design features which are essential in achieving high loading and minimizing the aspiration requirement are described. Design studies of two aspirated compressor stages and an aspirated turbine exit guide vane using three dimensional Navier-Stokes calculations are presented. The calculations show that high loading can be achieved over most of the blade span with a relatively small amount of aspiration. Three dimensional effects close to the endwalls are shown to degrade the performance to varying degrees depending on the loading level.